SG181950A1

SG181950A1 - A multi-layer structure and a method of forming the same

Info

Publication number: SG181950A1
Application number: SG2012047361A
Authority: SG
Inventors: Kazuya Takayama; Ieng Kin Lao
Original assignee: Nitto Denko Corp
Priority date: 2010-03-24
Filing date: 2010-08-10
Publication date: 2012-08-30
Also published as: WO2011119107A1; WO2011119104A1; SG183141A1; SG182817A1; WO2011119105A1; WO2011119106A1

Abstract

In an embodiment, a multi-layer structure may be provided. The multi-layer structure may include a waveguide (104); and at least one inclined in-guiding channel (106) optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, wherein the at least one inclined in-guiding channel may be configured to receive light and to direct the light to the waveguide such that the light may travel within the at least one inclined in-guiding channel by means of reflection into the waveguide. A method of forming the same may also be provided.

Description

A MULTI-LAYER STRUCTURE AND A METHOD OF FORMING THE SAME : Co Co Cross-reference to related applications

[0001] This application claims the benefit of priority of United States Provisional patent application number 61/317,194 filed on 24 March 2010 and United States Provisional patent application number 61/317,281 filed on 25 March 2010, the contents of which is : hereby incorporated by reference in its entirety for all purposes.

Technical Field

[0002] Embodiments relate to a multi-layer structure and a method of forming the same.

CL © Background

[0003] Generally, multi-layer structures are used for many various applications, such as being implemented as sensors for physical and/or chemical and/or biological applications, for example. A conventional multi-layer structure usually includes various differerit components such as light sources, photo detectors, waveguides, for example.

[0004] To achieve effective light coupling within the multi-layer structure, there is a need for an alternative multi-layer structure which may enhance the light coupling into and out of the waveguide by means of total internal reflection.

Summary

[0005] In various embodiments, a multi-layer structure may be provided. The multi- layer structure may include a waveguide; and at least one inclined in-guiding channel optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, wherein the at least one inclined in-guiding channel may be configured to receive light and to direct the light to the waveguide such that the light may : travel within the af least one inclined in-guiding channel by means of reflection into the waveguide. :

[0006] In various embodiments, a method of forming a multi-layer structure may be provided. The method may include forming a waveguide on a device substrate; and forming at least one inclined in-guiding channel on the waveguide such that the at least ; one inclined in-guiding channel may be optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, wherein the at least one inclined in-guiding channel may be configured to receive light and to direct the light to the waveguide such that the light may travel within the at least one inclined in-guiding channel by means of reflection into the waveguide.

Brief Description of the Drawings

[0007] In the drawings, like reference characters generally refer to the same parts "throughout the different views. - The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of various embodiments.

In the following description, various embodiments of the invention are described with : reference to the following drawings, in which:

FIG. 1 shows a side view of a multi-layer structure including a waveguide and four iriclined in-guiding channels according to an embodiment; .-. FIG. 2 shows a side view of a multi-layer structure including a waveguide, four inclined in-guiding channels and four inclined out-guiding channels according to an embodiment; oo

FIGs. 3A to 3K show respective side views of a multi-layer structure : according to an embodiment; . FIGs. 4A to 4G show respective cross-sectional views along A-A of the respective side views of the multi-layer structure as shown in FIGs. 3A to 3K according to an embodiment;

FIG. 5A shows a side view of a multi-layer structure including an I-shape waveguide, one inclined in-guiding channel and ome inclined out-guiding channel according to an embodiment; FIG. 5B shows a top view of the multi-layer structure as shown in FIG. 5A according to an embodiment; ++ FIG. 6A shows a side view of a multi-layer structure including an U-shape waveguide, ong inclined in-guiding channel and one inclined out-guiding channel according to an embodiment; FIG. 6B shows a top view of the multi-layer structure as shown in FIG. 6A according to an embodiment; "* FIG. 7 shows a side view of a multi-layer structure including a plurality of "inclined in-guiding channels, the plurality of inclined in-guiding channels being considered as a single region according to an embodiment;

FIG. 8 shows a side view of a multi-layer structure including a plurality of inclined in-guiding channels, each of the plurality of inclined in-guiding channels being considered individually according to an embodiment;

FIG. 9 shows a side view of a multi-layer structure including a waveguide, a - plurality of inclined in-guiding channels and an in-capping portion according to an embodiment;

FIG. 10A shows a side view of a multi-layer structure including a waveguide, ;

Co two inclined in-guiding channels and an in-capping portion with two plane surfaces : according to an embodiment; FIG. 10B shows a side view of a multi-layer structure including a waveguide, two inclined in-guiding channels and an in-capping portion with one curved portion pointing away from the waveguide according to an embodiment; FIG. - 10C shows a side view of a multi-layer structure including a waveguide, two inclined in- . guiding channels and an in-capping portion with two curved portions pointing away from the waveguide according to an embodiment; FIG. 10D shows a side view of a multi-layer structure including a waveguide, two inclined in-guiding channels and an in-capping portion with two curved portions pointing towards the waveguide according to an + embodiment;

FIG. 11 shows a side view of a multi-layer structure including a waveguide and four inclined out-guiding channels according to an embodiment;

FIG. 12A shows a side view of a multi-layer structure including a waveguide and four inclined’ out-guiding channels for use in a fifst scenario according to an - embodiment; FIG. 12B shows a side view of a multi-layer structure including a waveguide and four inclined out-guiding channels for use in a second scenario according to an embodiment; .

FIG. 13 shows a flow-~chart of a method of forming a multi-layer structure according to an embodiment; . FIG. 14A shows a flow-chart of an energy-assisted method of attaching a device substrate to a supporting substrate according to an embodiment; FIG. 14B shows a flow-chart of a method of attaching a device substrate to a supporting substrate according to an embodiment; : FIG. 15 shows a flow-chart of a method of forming an anti-refraction coating on a device substrate according to an embodiment;

FIG. 16A shows a flow-chart of a method of forming a waveguide, the method involving photolithography according to an embodiment; FIG. 16B shows a flow-chart of a method of forming a waveguide, the method involving imprinting according to an embodiment; FIG.16C shows a flow-chart of a method of forming a waveguide, the method involving hot embossing or thermal compression according to an "embodiment; FIG. 16D shows a flow-chart of a method of forming a waveguide, the method involving molding according to an embodiment; - -- FIG. 17A shows a flow-chart of a method of forming an inclined in-guiding channel or an inclined out-guiding channel, the method involving an inclined UV exposure according to an embodiment; FIG. 17B shows a flow-chart of a method of forming an inclined in-guiding channel or an inclined out-guiding channel, the method "involving laser excitation according to an embodiment; FIG. 17B’ shows a laser source positioned at a first position relative to a device substrate according to an embodiment;

FIG. 17B’’ shows a laser source positioned at a second position relative to a device substrate according to an embodiment; FIG.17C shows a flow-chart of a method of forming an inclined in-guiding channel or an inclined out-guiding channel, the method involving imprinting according to an embodiment; FIG. 17D shows a flow-chart of a method of forming an inclined in-guiding channel or an inclined out-guiding channel, the method involving hot embossing: or thermal compression according to an embodiment;

FIG. 17E shows a flow-chart of a method of forming an inclined in-guiding channel or an inclined out-guiding channel, (the method involving molding according to an "embodiment; :

FIG. 18A shows a flow-chart of a method of forming an in-capping portion or an out-capping portion, the method involving ultra-violet exposure of an existing layer according to an embodiment; FIG. 18B shows a flow-chart of a method of forming an in- capping portion or an out-capping portion, the method involving ultra-violet exposure of an additional layer according to an embodiment; FIG. 18C shows a flow-chart of a method of forming an in-capping portion or an out-capping portion, the method involving depositing an additional unexposed layer according to an embodiment; FIG. 18D shows a + flow-chart of a method of forming an in-capping portion or an out-capping portion, the method involving photolithography of an additional layer according to an embodiment;

FIG. 18E shows a flow-chart of a method of forming an in-capping portion or an out- capping portion, the method involving imprinting according to an embodiment; FIG. 18F shows. a flow-chart of a method of forming an in-capping portion or an out-capping - portion, the method involving hot embossing or thermal compression according to an embodiment; FIG. 18G shows a flow-chart of a method of forming an in-capping portion or an out-capping portion, the method involving molding according to an embodiment; and

.- . FIG. 19A shows a flow-chart of an energy-assisted method of detaching a device substrate from a supporting substrate according to an embodiment; FIG. 19B shows a flow-chart of a’ mechanical method of detaching a device substrate from a supporting substrate according to an embodiment.

Description

[0008] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and : structural, logical, and electrical changes may be made without departing from the scope of the invention. The various embodiments are not necessarily mutually exclusive, as "some embodiments can be combined with one or more other embodiments to form new - embodiments. © . Co - ~~ [0009] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs:

[0010] An embodiment may provide a multi-layer structure. The multi-layer structure may include a waveguide; and at least one inclined in-guiding channel optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, wherein the at least one inclined in-guiding channel may be configured to receive light and to direct the light to the waveguide such that the light may travel within the at least one inclined in-guiding channel by means of reflection into the waveguide.

[0011] In an embodiment, the waveguide may include any suitable number of layers. For example, the waveguide may include one layer (i.e. core), or two layers (one core, one cladding) or three layers (one core and two cladding), or a stacked layer arrangement (for example, two core and two cladding, one after another in an alternating arrangement).

[0012] In an embodiment, the multi-layer structure may further include at least one inclined out-guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide. :

[0013] In an embodiment, the first predetermined non-zero angle may be measured in a clockwise direction from the surface of the waveguide while the second predetermined non-zero angle may be measured in an anti-clockwise direction from the surface of the waveguide or vice versa. However, both the first predetermined non-zero angle and the . second pre-determined non-zero angle may also be measured in a same clockwise direction or anti-clockwise direction from the surface of the waveguide. . [0014] In an embodiment, the at least one inclined out-guiding channel may be configured to direct the light out of the waveguide such that the light exiting the waveguide may travel within the at least one inclined out-guiding channel.

[0015] In an embodiment, the multi-layer structure may further include an in-capping portion disposed above the at least one inclined in-guiding channel, wherein the in- capping portion may include at least one planar surface for subsequent arrangement ofa component. The in-capping portion may be of any suitable shape, dimension or’ orientation depending on user and design requirements. © [0016] ‘Tn an embodiment, the multi-layer structure may further include an out-capping portion disposed above the at least one inclined out-guiding channel, wherein the out- capping portion may include at least one planar surface for subsequent arrangement ofa component. The out-capping portion may also be of any suitable shape, dimension or orientation depending on user and design requirements.

[0017] In an embodiment, the in-capping portion and the at least one inclined in-guiding channel may be formed as a single integrated portion and/or the out-capping portion and the at least one light out-capping module may be formed as a single integrated portion.

[0018] In an embodiment, the in-capping portion may be the same as or different from "the out-capping portion. For example, the in-capping portion may be similar or different in shape, dimension or orientation with the out-capping portion.

[0019] Tn an embodiment, the multi-layer structure may further include at least one first - active optical element that may be an organic or inorganic light source, disposed above the at least one inclined in-guiding channel.

[0020] In an embodiment, the at least one first active optical element may be disposed above the in-capping portion.

[0021] In an embodiment, the at least one first active optical element may include at least one light source that may be an organic, inorganic or a combination of organic and inorganic, configured to provide the light.

[0022] In an embodiment, the multi-layer structure may further include at least one second active optical element disposed above the inclined out-guiding channel.

[0023] In an embodiment, the at least one second active optical element may be disposed above the out-capping portion. :

[0024] In an embodiment, the at least one second active optical element may include at least one photo detector that may be an organic, inorganic or a combination of organic and inorganic. :

[0025] In an embodiment, the at least one inclined in-guiding channel may be directly

Co coupled to the waveguide such that light may be coupled in directly from the at least one _ inclined in-guiding channel into the waveguide. In this regard, the at least one inclined in- guiding channel may be configured to direct light emitted from the light source to the waveguide.

[0026] Similarly, the at least one inclined out-guiding channel may be directly coupled to the waveguide such that light may be coupled directly out from the waveguide The at least. one inclined’ out-guiding channel may be configured to direct light exiting the . waveguide to the photo detector. .

[0027] There may be a presence of an intermediate structure or layer positioned between the at least one inclined in-guiding channel and the waveguide or between the waveguide and the at least one inclined out-guiding channel. The intermediate structure or layer may provide the following advantages, such as barrier function or as a substrate during

: individual component fabrication while the multi-layer structure may be integrated through hybrid integration (e.g. bonding). The intermediate structure or layer may not be . necessary for monolithic integrated multi-layer structure unless the intermediate structure or layer provides an additional purpose e.g. barrier, improve adhesion for example.

[0028] There may not be an indirect light coupling mechanism (i.e. require an intermediate structure for light coupling) for coupling light from the at least one inclined in-guiding channel into the waveguide. In addition, there may not also be an indirect light coupling mechanism for coupling light out from the waveguide to the at least one inclined out-guiding channel. In this regard, light from the at least one inclined in-guiding channel may be channeled directly into the waveguide and then out to the at least one inclined out-guiding channel.

[0029] In an embodiment, the at least one inclined in-guiding channel may include one or a plurality of inclined in-guiding channels. The number of inclined in-guiding channels may vary depending on user and.design requirements. - :

[0030] In an embodiment, each of the plurality of inclined in-guiding channels may be arranged at any suitable position above the waveguide.

[0031] In an embodiment, each of the plurality of inclined in-guiding channels may be inclined at the same or different first predetermined non-zero angle from another of the plurality of inclined in-guiding channels.

[0032] In an embodiment, each of the plurality of inclined in-guiding channels may be spaced apart by a same or different first distance from another of the plurality of inclined in-guiding channels.

[0033] In an embodiment, the at least one inclined out-guiding channel may include one or a plurality of inclined out-guiding channels. The number of inclined out-guiding channels may vary depending on user and design requirements.

[0034] In an embodiment, each of the plurality of inclined out-guiding channels may be arranged at any suitable position above the waveguide.

[0035] In an embodiment, the plurality of inclined in-guiding channels may be arranged at a same surface of the waveguide as the plurality of inclined out-guiding channels so - that light may enter and exit the waveguide from the same surface. oC [0036] In an embodiment, each of the plurality of inclined out-gniding channels may be - inclined at a same or different second predetermined non-zero angle from another of the plurality of inclined out-guiding channels. .. [0037] In an embodiment, each of the plurality of inclined out-guiding channels may be ~~ spaced ‘apart by a same or different second distance from another of the plurality of inclined out-gniding channels. - .

[0038] In an embodiment, the first distance may include a value substantially the same as or different from the second distance.

[0039] In an embodiment, the first distance may include a value between 10 um to mm, for example. For different physical mechanisms, there may be different values for the first distance. For example, for a photonic crystal structure, the first distance may

: be in the nm range, for a refraction grating, the first distance may be in the sub-um range, and for a light channel bundle, the first distance may be in the mm range. © [0040] In an embodiment, the second distance may include a value between 10 um to 10 mm, for example. Similar to that for the first distance, for different physical mechanisms, there may be different values for the second distance. For example, for a photonic crystal structure, the second distance may be in the nm range, for a refraction grating, the second distance may be in the sub-um range, and for a light channel bundle, the second distance may be in the mm range.

[0041] In an embodiment, the first predetermined angle may include a value substantially the same as or different from the second predetermined angle.

[0042] In an embodiment, the first predetermined non-zero angle may include a value between about 1° and about 179°, for example.

[0043] In an embodiment, the second predetermined non-zero angle may include a value between about 1° and about 179°; for example.

[0044] In an embodiment, the at least one inclined in-guiding channel may be substantially non-wavelength selective. The terms “wavelength selective” and “non- wavelength selective” have a clear and plain meaning to reflect the bandwidth "characteristics of optical components, including a coupling arrangement. Such terminology has been widely used in the art of optics and are incorporated in various industrial standards, e.g., EVS-EN 181101:1995 “Specification for Harmonized system of quality assessment for electronic components - Blank detail specification - Fibre optic branching devices - Type: Non wavelength selective transmissive star”, CEI IEC 60875- 1:2000” Non-wavelength-selective-fibre optic branching devices. Part 1. Generic specification”, and IEC 61753-031-3:2009 “Fibre optic interconnecting devices and passive components performance standard - Part 031-3: Non-connectorized single-mode 1xN and 2xN non-wavelength-selective branching devices (NWBD) for Category U -

Uncontrolled environment”.

[0045] Such terminology has also been well understood by people skilled in the art and implemented in various applications, for example, US 4,737,007 ‘“Narrow-band wavelength selective optical coupler”, US 6,320,996 “Wavelength selective optical switch”, W0/2001/029596 “Optical wavelength multiplexing device and WDM optical telecommunication system”, US20090274176 “Compact, thermally stable multi-laser © engine”. :

[0046] The term “non-wavelength selective typically means that the difference of the . attenuation of the incoming optical signal at different wavelengths may be negligible, and as such, the shape of the spectra of the incoming optical signal remains substantially the same after being coupled into thé waveguide or out to the photo detector. More generally, a person skilled in the art of optics will understand the two terms as follows.

[0047] Wavelength selective: Narrowband - responding only to particularly narrow " bandwidth wavelength because coupling efficiency of light coupling arrangement is affected by wavelength dispersion of refractive index of the waveguide.

[0048] Non-wavelength selective: Broadband - covering significantly broad bandwidth wavelength because coupling efficiency of light coupling arrangement is not affected by

: wavelength dispersion of refractive index of the waveguide, due to multimode size of module (inclined in-guiding channel/inclined out-guiding channel) and RI of material insignificantly dependent of the wavelength, further implying that attenuation is thus negligible.

[0049] In an embodiment, the at least one inclined in-guiding channel may be substantially non-wavelength selective in a wavelength range from about 400 nm to about : 1700 nm, for example.

[0050] In an embodiment, the at least one inclined in-guiding channel may include one or more materials selected from a group of materials consisting of polymer materials, metals, metal oxides, electro-opto organic materials and thermal-opto organic materials, . . forexample. ~~ - Co * [0051] Ini an embodiment, the at least one inclined in-guiding channel may be the same as or different from the at least one inclined out-guiding channel. For example, the at least one inclined in-guiding channel may be similar or different in shape, dimension, number or orientation with the at least one inclined out-guiding channel.

[0052] In an embodiment, the waveguide may include a same or different material as the at least one inclined in-guiding channel and the at least one inclined out-guiding channel. . [0053] In an embodiment, the waveguide, the at least one inclined in-guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element may be integrated.

[0054] In an embodiment, the waveguide, the at least one inclined in-guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element may be monolithically integrated.

[0055] In an embodiment, the waveguide, the at least one inclined in-guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the out-capping . portion, the at least one first active optical element and the at least one second active optical element may include organic material.

[0056] In an embodiment, the multi-layer structure may be packaged or encapsulated.

[0057] In an embodiment, the at least one first active optical element and the at least one second active optical element may include inorganic material.

[0058] In an embodiment, the waveguide may be disposed on a device substrate. The . device substrate may include a material selected from a group consisting of silicon, : polymer, glass, plastic, metal sheet, and ceramic. The device substrate may also include a barrier film or a flexible film substrate. ~~ -

[0059] An embodiment may provide a method of forming a multi-layer structure. The method may include forming a waveguide; and forming at least one inclined in-guiding "channel on the waveguide such that the at least one inclined in-guiding channel may be optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, wherein the at least one inclined in-guiding channel may be configured to receive light and to direct the light to the waveguide such that the light may

: travel within the at least one inclined in-guiding channel by means of reflection into the waveguide.

[0060] In an embodiment, the method may further include forming at least one inclined out-guiding channel on the waveguide such that the at least one inclined out-guiding channel may be optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide.

[0061] In an embodiment, forming the at least one inclined out-guiding channel on the waveguide may include forming the at least one inclined out-guiding channel such that the at least one inclined out-guiding channel may be configured to direct the light out of : the waveguide such that the light exiting the waveguide may travel within the at least one . inclined out-guiding channel.

[0062] In an embodiment, the method may further include forming an in-capping portion . above!the at least one inclined in-guiding channel, wherein the in-capping portion may include at least one planar surface for subsequent arrangement of a component.

[0063] In an embodiment, the method may further include forming an out-capping portion above the at least one inclined out-guiding channel, wherein the out-capping portion may include at least one planar surface for subsequent arrangement of a ‘ component.

[0064] In an embodiment, forming the in-capping portion may be the same as or different : from forming the out-capping portion.

[0065] In an embodiment, the method may further include forming at least one first active optical element above the at least one inclined in- guiding channel.

[0066] In an embodiment, the forming the at least one first active optical element above the at least one inclined in-guiding channel may include forming the at least one first active optical element above the in-capping portion. . [0067] In an embodiment, the at least one first active optical element may include at least . one light source configured to provide the light.

[0068] In an embodiment, the method may further include forming at least one second active optical element above the at least one inclined out-guiding channel.

[0069] In an embodiment, the forming the at least one second active optical element above the at least one inclined out-guiding channel may include forming the at least one second active optical element above the out-capping portion. -. [0070] In an embodiment, the at least one second active optical element may include at least one photo detector. so Co 2

[0071] In an embodiment, forming the at least one inclined in-guiding channel on the waveguide may include forming the at least one inclined in-guiding channel such that the at least one inclined in-guiding channel may include a plurality of inclined in-guiding channels.

[0072] In an embodiment, forming the plurality of inclined in-guiding channels may further include forming each of the plurality of inclined in-guiding channels inclined at wo 2011/119106 PCT/SG2010/000295 . the same or different first predetermined non-zero angle from another of the plurality of inclined in-guiding channels. ~ [0073] In an embodiment, forming the plurality of inclined in-guiding channels may further include forming each of the plurality of inclined in-guiding channels spaced apart : by a same or different first distance from another of the plurality of inclined in-guiding channels.

[0074] In an embodiment, forming the at least one inclined out-guiding channel on the waveguide may include forming the at least one inclined out-guiding channel such that the at least one inclined out-guiding channel may include a plurality of inclined out- ~ guiding channels. . © [0075] In an embodiment, forming the plurality of inclined out-guiding channels may further include forming each of the plurality of inclined out-guiding channels inclined at the same or different second predetermined non-zero angle from another of the plurality of inclined out-guiding channels.

[0076] In an embodiment, forming the plurality of inclined out-guiding channels may further include forming each of the plurality of inclined out-guiding channels spaced apart by a same or different second distance from another of the plurality of inclined out- guiding channels. :

[0077] In an embodiment, the first distance may include a value substantially the same as or different from the second distance.

[0078] In an embodiment, the first distance may include a value between 10 um to 10 mm, for example.

[0079] In an embodiment, the second distance may include a value between 10 um to 10 mm, for example. :

[0080] In an embodiment, the first predetermined angle may include a value substantially the same as or different from the second predetermined angle.

[0081] In an embodiment, the first predetermined non-zero angle may include a value between 1° and 179°, for example. - [0082] In an embodiment, the second predetermined non-zero angle may include a value between 1° and 179°, for example. © [0083] In an embodiment, the at least one inclined in-guiding channel may be substantially non-wavelength selective. + [0084] In an embodiment, the at least one inclined in-guiding channel may be substantially non-wavelength selective in a wavelength range from about 400 nm to about 1700 nm, for example.

[0085] In an embodiment, the at least one inclined in-guiding channel may include one or _ more materials selected from a group of materials consisting of polymer materials, metals, metal oxides, electro-opto organic materials and thermal-opto organic materials, for example.

. [0086] In an embodiment, forming the at least one inclined in-guiding channel may be the same as or different from forming the at least one inclined out-guiding channel. © [0087] In an embodiment, the waveguide may include a same or different material as the at least one inclined in-guiding channel and the at least one inclined out-guiding channel.

[0088] In an embodiment, forming the waveguide, the at least one inclined in-guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the out- capping portion, the at least one first active optical element and the at least one second active optical element comprises forming the waveguide, the at least one inclined in- : guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the - out-capping portion, the at least one first active optical element and the at least one . second active optical element such that the waveguide, the at least one inclined in- guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the _. out-capping portion, the at least one first active optical element and the at least one second active optical element may be integrated.

[0089] In an embodiment, forming the waveguide, the at least one inclined in-guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the out- capping portion, the at least one first active optical element and the at least one second active ‘optical element may include forming the waveguide, the at least one inclined in- "guiding channel, the at least one inclined out-gniding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element such that the waveguide, the at least one inclined in- guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element may be monolithically integrated.

[0090] In an embodiment, the waveguide, the at least one inclined in-guiding channel, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active : optical element may include organic material.

[0091] In an embodiment, the at least one first active optical clement and the at least one second active optical element may include inorganic material.

[0092] In an embodiment, forming the at least one inclined in-guiding channel on the : waveguide may include depositing a light in-coupling layer above the surface of the waveguide.

[0093] In an embodiment, forming the at least one inclined in-guiding channel on the waveguide may further include directly shining an UV laser source over the light in- coupling layer. ~~ . :

[0094] In an embodiment, forming the at least one inclined in-guiding channel on the wavegnide may further include positioning the UV laser source at a first laser predetermined non-zero angle relative to the light in-coupling layer. * [0095] In an embodiment, forming the at least one inclined in-guiding channel on the waveguide may further include exposing ultra-violet radiation at a first exposure predetermined non-zero angle relative to the light in-coupling layer.

: [0096] In an embodiment, the first laser predetermined non-zero angle may be the same or different from the first predetermined non-zero angle.

[0097] In an embodiment, the first exposure predetermined non-zero angle may be the same or different from the first predetermined non-zero angle.

[0098] In an embodiment, forming the at least one inclined out-guiding channel on the waveguide may include depositing a light out-coupling layer above the surface of the waveguide.

[0099] In an embodiment, forming the at least one inclined out-guiding channel on the waveguide may further include directly positioning a further UV laser source over the . light out-coupling layer. :

[00100]. © In an embodiment, forming the at least one inclined out-guiding channel on the waveguide may further include positioning the further UV laser source at a second laser predetermined non-zero angle relative to the light out-coupling layer.

[00101] In an embodiment, forming the at least one inclined out-gniding channel on the waveguide may further include exposing ultra-violet radiation at a second exposure predetermined non-zero angle relative to the light out-coupling layer.

[00102] In an embodiment, the second laser predetermined non-zero angle may be the same or different from the second predetermined non-zero angle. © [00103] In an embodiment, the second exposure predetermined non-zero angle may be the same or different from the second predetermined non-zero angle.

[00104] In an embodiment, the method of forming the respective layers within the multi-layer structure may be layer-by-layer (monolithic), bonding or combination of layer-by-layer and bonding. Bonding may be carried out by pick-and-place, compression, flat plate lamination, roller lamination, plasma for example. Bonding may also be achieved by UV illustration, heating up through pressure-sensitive adhesive molecule layer, pressure sensitive adhesive tape, for example.

[00105] FIG. 1 shows a side view of a multi-layer structure 102 including a waveguide 104 and four inclined in-guiding channels 106 according to an embodiment.

[00106] The multi-layer structure 102 may include the waveguide 104 and four inclined in-guiding channels 106 optically coupled to the waveguide 104. Each of the four inclined in-guiding channels 106 may be inclined at a first predetermined non-zero angle 108 to a surface 110 of the waveguide 104, wherein each of the four inclined in- guiding channels 106 may be configured to receive light and to direct the light to the . waveguide 104 such that the light may travel within each of the four inclined in-guiding channels 106 to the waveguide 104. ©. [00107] The number of the inclined in-guiding channels: 106 may vary depending on user and design requirement. There may be four inclined in-guiding channels 106 for examplé as shown in FIG. 1. Each of the four inclined in-guiding channels 106 may be arranged at any suitable position above the waveguide 104. For example, each of the four inclined in-guiding channels 106 may be arranged such that the four inclined in- _ guiding channels 106 may be substantially parallel to each other.

[00108] Each of the four inclined in-guiding channels 106 may be inclined at the same or different first predetermined non-zero angle 108 from another of the four inclined in-

CL : 12 wo 2011/119106 PCT/SG2010/000295 guiding channels 106. The first predetermined non-zero angle 108 may include a value : between 1° and 179°, for example. " [00109] Each of the four inclined in-guiding channels 106 may be spaced apart by a same or different first distance “d1” (or gap) from another of the four inclined in-guiding channels 106. The first distance may include a value between 10 um to 10 mm, for example.

[00110] Each of the four inclined in-guiding channels 106 may be substantially non- wavelength selective. Each of the four inclined in-guiding channels 106 may be substantially non-wavelength selective in a wavelength range from about 400 nm to about 1700 nm, for example. The material and the multimode size of the inclined in-guiding . channel (or module) may have an extremely low transmission loss within the large wavelength range, and the RI may have weak dependence on the wavelength.

[00111] Bach of the four inclined in-guiding channels 106 may include one or more materials selected from a group of materials consisting of polymer materials, metals, metal oxides, electro-opto organic materials and thermal-opto organic materials for example.

[00112] The waveguide 104 may include a same or different material as each of the four inclined in-gniding channels 106. The waveguide may also be multiple-mode (i.e. several propagation modes within one waveguide).

[00113] The waveguide 104 and the four inclined in-guiding channels 106 may be integrated. For example, the waveguide 104 and the four inclined in-guiding channels 106 may be monolithically integrated. :

[00114] The waveguide 104 and each of the four inclined in-guiding channels 106 may include organic material.

[00115] The direction of light entering into each of the four inclined in-guiding i : channels 106 and the waveguide 104 are as shown by the arrows in FIG. 1.

[00116] FIG. 2 shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106 and four inclined out-guiding channels 112 according to an embodiment.

[00117] The multi-layer structure 102 as shown in FIG. 2 may be similar to the multi- layer structure 102 as shown in FIG. 1 with the addition of four inclined out-guiding - channels 112. _ -

[00118]° Like in FIG. 1, the multi-layer structure 102. in FIG. 2 may include a . waveguide 104 and four inclined in-guiding channels 106 optically coupled to the waveguide 104. Each of the four inclined in-guiding channels 106 may be inclined at a first predetermined non-zero angle 108 to a surface 110 of the waveguide 104, wherein each of the four inclined in-guiding channels 106 may be configured to receive light and to direct the light to the waveguide 104 such that the light may travel within each of the . four inclined in-guiding channels 106 to the waveguide 104.

[00119] The multi-layer structure 102 may further include four inclined out-guiding channels 112 optically coupled to the waveguide 104. Each of the four inclined out-

Cn Le Lo 13

. guiding channels 112 may be inclined at a second predetermined non-zero angle 114 to the surface 110 of the waveguide 104.

[00120] The first predetermined non-zero angle 108 may be measured in a clockwise direction from the surface 110 of the waveguide 104 while the second predetermined non-zero angle 114 may be measured in an anti-clockwise direction from the surface 110 of the waveguide 104 or vice versa. However, both the first predetermined non-zero angle 108 and the second predetermined non-zero angle 114 may also be measured in a same clockwise direction or anti-clockwise direction from the surface 110 of the waveguide 104. -

[00121] Each of the four inclined out-guiding channels 112 may be configured to . direct the light out of the waveguide 104 such that the light exiting the waveguide 104 may travel within each of the four inclined out-guiding channels 112.

[00122] The number of inclined in-guiding channels 106 may vary depending on user and design requirements. There may be four inclined in-guiding channels 106 for example as shown in FIG. 2. Each of the four inclined in-guiding channels 106 may be arranged at any suitable position above the waveguide 104.

[00123] Each of the four inclined in-guiding channels 106 may be inclined at the same _ or different first predetermined non-zero angle 108 from another of the four inclined in- guiding channels 106.

[00124] Each of the four inclined in-guiding channels 106 may be spaced apart by a same or different first distance “d1” from another of the four inclined in-guiding channels 106.

[00125] The number of inclined out-guiding channels 112 may vary depending on user and design requirements. There may be four inclined out-gniding channels 112 for example as shown in FIG. 2. Each of the four inclined out-guiding channels 112 may be arranged at any suitable position above the waveguide 104. The four inclined in-guiding channels 106 may be arranged at a same surface 110 of the waveguide 104 as the four inclined out-guiding channels 112 so that light may enter and exit the waveguide 104 : from the same surface 110.

[00126] Each of the four inclined out-guiding channels 112 may be inclined at a same : or different second predetermined non-zero angle 114 from another of the four inclined out-guiding channels 112. © [00127] - Each of the four inclined out-guiding channels 112 may be spaced apart by a same or different second distance “d2” (or gap) from another of the four inclined out- "guiding channels 112. :

[00128] The first distance may include a value substantially the same as the second distance. The first distance may include a value between about 10 um to about 10 mm, for example. The second distance may include a value between about 10 um to . about 10 mm, for example.

[00129] The first predetermined non-zero angle 108 may include a value substantially the same as the second predetermined non-zero angle 114. The first predetermined non- zero angle 108 may include a value between about 1° and about 179°, for example. The

STE 14

. second predetermined non-zero angle 114 may include a value between about 1° and about 179°, for example. + [00130] Each of the four inclined in-guiding channels 106 may be substantially non- wavelength selective. Each of the four inclined in-guiding channels 106 may be substantially non-wavelength selective in a wavelength range from about 400 nm to about 1700 nm, for example.

[00131] Each of the four inclined in-guiding channels 106 may include one or more materials selected from a group. of materials consisting of polymer materials, metals, metal oxides, electro-opto organic. materials and thermal-opto organic materials, for © example. Co :

[00132] Each of the four inclined in-guiding channels 106 may be the same or different as each of the four inclined out-guiding channels 112. For example, each of the four inclined in-guiding channels 106 may be similar or different in shape, dimension, number or orientation with each of the four inclined out-guiding channels 112.

[00133] The waveguide 104 may include a same or different material as each of the four inclined in-guiding channels 106 and each of the four inclined out-gniding channels : 112.. The waveguide may also be multiple-mode waveguide (i.e. several propagation ~ modés within one waveguide). | -

[00134] The waveguide 104, the four inclined in-guiding channels 106 and the four inclined out-guiding channels 112 may be integrated. For example, the waveguide 104, the four inclined in-guiding channels 106 and the four inclined out-guiding channels 112 may be monolithically integrated.

[00135] The waveguide 104, each of the four inclined in-guiding channels 106 and each of the four inclined out-guiding channels 112 may include organic material.

[00136] The direction of light entering into each of the four inclined in-guiding channels 106, the waveguide 104 and exiting from each of the four inclined out-guiding channels 112 are as shown by the arrows in FIG. 2.

[00137] FIGs. 3A to 3K show respective side views of a multi-layer structure 102 according to an embodiment. © [00138] FIG. 3A shows a side view of a multi-layer structure 102 including a waveguide 104 and four inclined in-guiding channels 106. The multi-layer structure 102 as shown in FIG. 3A may be similar to the multi-layer structure 102 as shown in FIG. 1.

[00139] The waveguide 104 may include any suitable number of layers. For example, the waveguide 104 may include one layer (i.e. core), or two layers (one core, one * cladding) or three layers (one core and two cladding), or a stacked layer arrangement (for example, two core and two cladding, one after another in an alternating arrangement).

[00140] FIG. 3B shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106 and four inclined out-guiding channels 112. The multi-layer structure 102 as shown in FIG. 3B may be similar to the * multi-layer structure 102 as shown in FIG. 2.

[00141] FIG. 3C shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106 and an in-capping portion 116.

: [00142] The multi-layér structure 102 as shown in FIG. 3C may be similar to the multi-layer structure 102 as shown in FIG. 3A with an addition of the in-capping portion 116. ’

[00143] As shown in FIG. 3C, the in-capping portion 116 may be disposed above the four inclined in-guiding channels 106, wherein the in-capping portion 116 may include at least ‘one planar surface for subsequent arrangement of a component. The in-capping portion 116 may be of any suitable shape, dimension or orientation depending on user and design requirements. "-

[00144] The waveguide 104, the four inclined in-guiding channels 106 and the in- capping, portion 116 may be integrated. For example, the waveguide 104, the four : inclined in-guiding channels 106 and the in-capping portion 116 may be monolithically integrated. : [00145] The waveguide 104, the four inclined in-guiding channels 106 and the in- : capping portion 116 may include organic material.

[00146] FIG. 3D shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106, an. in-capping portion 116 and four inclined out-guiding channels 112. ~~ [00147]. © The multi-layer structure 102 as shown in FIG. 3D may be similar to a combination of the multi-layer structures 102 as shown in FIGs. 3B and 3C.

[00148] FIG. 3E shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106, four inclined out-guiding channels 112 and an out-capping portion 118. :

[00149] The multi-layer structure 102 as shown in FIG. 3E may be similar to the - multi-layer structure 102 as shown in FIG. 3D with a difference such that the multi-layer structure 102 in FIG. 3D includes the in-capping portion 116 while the multi-layer structure 102 as shown in FIG. 3E includes the out-capping portion 118.

[00150] In FIG. 3E, the out-capping portion 118 may be disposed above the four inclined out-guiding channels 112, wherein the out-capping portion 118 may include at least one planar surface for subsequent arrangement of a component. The out-capping portion 118 may be of any suitable shape, dimension or orientation depending on user

Co and design requirements. oo

[00151] The ouf-capping portion 118 as shown in FIG. 3E may be the same as or different from the in-capping portion 116 as shown in FIG: 3D. For example, the out- - capping portion 118 as shown in FIG. 3E may be similar or different in shape, dimension . or orientation from the in-capping portion 116 as shown in FIG. 3D.

[00152] FIG. 3F shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106, an in-capping portion 116, four inclined out-guiding channels 112 and an out-capping portion 118.

[00153] The multi-layer structure 102 as shown in FIG. 3F may be similar to a "combination of the multi-layer structures 102 as shown in FIGs. 3D and 3E.

[00154] FIG. 3G shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106, a first active optical element 120, : four inclined out-guiding channels 112 and a second active optical element 122.

A 16 oo

: [00155] The multi-layer structure 102 as shown in FIG. 3G may be similar to the multi-layer structure 102 as shown in FIG. 3F with a difference such that the multi-layer structure 102 in FIG. 3G includes the first active optical element 120 and the second active optical element 122 while the multi-layer structure 102 as shown in FIG. 3F includes the in-capping portion 116 and the out-capping portion 118.

[00156] In FIG. 3G, the multi-layer structure 102 may further include the first active optical element 120 disposed above the four inclined in-gniding channels 106 and the second. active optical element 122 disposed above the four inclined out-guiding : channels 112. ;

[00157] The first active optical element 120 may include a light source configured to . provide the light and the second active optical element 122 may include a photo detector or vice versa depending on user and design requirements. Depending on the position of the light source, the direction of light and the orientation of the four inclined in-guiding : channels 106 and the four inclined out-guiding channels 112 may change. -

[00158] The waveguide 104, the four inclined in-guiding channels 106, the four inclined out-guiding channels 112, the first active optical element 120 and the second active optical element 122 may be monolithically integrated. ©. [00159] The wavegnide 104, the four inclined in-guiding channels 106, the four inclined out-guiding channels 112, the first active optical element 120 and the second active optical element 122 may include organic material. Alternatively, the first active optical element 120 and/or the second active optical element 122 may include inorganic material.

[00160] FIG. 3H shows a side view of a multi-layer structure 102 including a - waveguide 104, four inclined in-guiding channels 106, an in-capping portion 116, a first active optical element 120, four inclined out-guiding channels 112, an out-capping portion 118 and a second active optical element 122.

[00161] The multi-layer structure 102 as shown in FIG. 3H may be similar to a combination of the multi-layer structures 102 as shown in FIGs. 3F and 3G.

[00162] For example, the waveguide 104, the four inclined in-guiding channels 106, the four inclined out-guiding channels 112, the in-capping portion 116, the out-capping portion 118, the first active optical element 120 and the second active optical element 122. may be monolithically integrated. :

[00163] FIG. 3I shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106, an in-capping portion 116, a first . transparent substrate 124, a first active optical element 120, four inclined out-guiding channels 112, an out-capping portion 118, a second transparent substrate 126 and a second active optical element 122.

[00164] The multi-layer structure 102 as shown in FIG. 31 may be similar to the multi- layer structure 102 as shown in FIG. 3H with an addition of the first transparent . substrate 124 and the second transparent substrate 126.

[00165] The first transparent substrate 124 may be arranged between the in-capping portion 116 and the first active optical element 120 and the second transparent substrate 126 may be arranged between thé out-capping portion 118 and the second active optical element 122. The first transparent substrate 124 and the second transparent substrate 126 which can be in multiples (i.e. more first transparent substrate 124 and second transparent substrate 126 may be possible if required) may also be positioned between any suitable layers of the multi-layer structure 102. The purpose of including the respective first transparent substrate 124 and the second transparent substrate 126 may act as for example, respective barrier layers to protect the first active optical element 120 and the : second active optical element 122 from humidity and therefore prevent degradation such as by oxidation, or having supportitig purposes for holding the first active optical element 120 and the second active optical element 122. Moisture may cause degradation other than oxidation only, especially for organic molecule and polymer material. : [00166] Each of the first transparent substrate 124 and the second transparent substrate 126 may be transparent at wavelength between about 400 nm to about 1700 nm, for : example. Further, there may be more than one first transparent substrate 124 and second transparent substrate 126 depending on user and design requirements.

[00167] The first transparent substrate 124 may include inorganic or organic materials, for example polymer, glass, plastic, metal oxide, metal matrix with nanoparticles, silicon dioxide, silicon nitrate, silicon carbide and the second transparent substrate 126 may include inorganic or organic materials, for example polymer, glass, plastic, metal oxide, . metal matrix with nanoparticles; silicon dioxide, silicon nitrate, silicon carbide. For example, the first transparent substrate 124 may be of the same or different material, dimension, orientation as the second transparent substrate 126.

[00168] FIG. 3J shows a side view of a multi-layer structure 102 including a waveguide 104, four inclined in-guiding channels 106, an in-capping portion 116, a first adhesive layer 128, a first active optical element 120, four inclined out-guiding channels - 112, an out-capping portion 118, a second adhesive layer 130 and a second active optical element 122.

[00169] The multi-layer structure 102 as shown in FIG. 3J may be similar to the multi- layer structure 102 as shown in FIG. 31 with the differences such that the respective first transparent substrate 124 and the second transparent substrate 126 as shown in FIG. 31 may be replaced with the respective first adhesive layer 128 and the second adhesive layer 130 as shown in FIG. 3J.

[00170] Similar to the first transparent substrate 124 and the second transparent substrate 126, the respective first adhesive layer 128 and the second adhesive layer 130 in

FIG. 3] may also be positioned between any suitable layers of the multi-layer structure 102. Further, there may be more than one first adhesive layer 128 and second adhesive layer 130 depending on user and design requirements.

[00171] The first, adhesive layer 128 may include for example, polyvinyl acetate, epoxy, polyurethane, cyanoacrylate polymers and the second adhesive layer 130 may include for example, polyvinyl acetate, epoxy, polyurethane, cyanoacrylate polymers. For example, the first adhesive layer 128 may be of the same or different material, dimension or orientation as the second adhesive layer 130.

[00172] In an embodiment, the multi-layer structure 102 may also include a combination of first transparent substrate 124, second transparent substrate 126, first

. adhesive layer 128 and'second adhesive layer 130 depending on user and design requirements.

[00173] FIG. 3K shows a side view of a multi-layer structure 102 including a device substrate 132, a waveguide 104, four inclined in-guiding channels 106, an in-capping portion 116, a first transparent substrate 124, a first active optical element 120, four inclined out-guiding channels 112, an out-capping portion 118, a second transparent substrate 126 and a second active optical element 122. :

[00174] The multi-layer structure 102 as shown in FIG. 3K may be similar to the multi-layer structure 102 as shown in FIG. 31 with an addition of the device substrate 132.

[00175] The waveguide 104 may be disposed on the device substrate 132. The device substrate 132 may include a material selected from a group consisting of silicon, silicon substrate, paper, aluminium foil, glass, plastics (e.g. acrylic, polyimide, polycarbonate, ~~ polyethylene terephthalate, and polyethylene naphthalate). The device substrate 132 may : be of a similar or different dimension, shape as the waveguide 104.

[00176] FIGs. 4A to 4G show respective cross-sectional views along A-A and B-B of the respective side views of the multi-layer structure 102 as shown in FIGs. 3A to 3K according to an embodiment. © [00177] FIG. 4A shows a cross-sectional view along A-A of the respective multi-layer structures 102 as shown in FIGs. 3A, 3B and 3E or a cross-sectional view along B-B of the respective multi-layer structures 102 as shown in FIGs. 3B and 3D.

[00178] If a cross-section may be taken along A-A of the respective multi-layer structures 102 as shown in FIGs. 3A, 3B and 3E, FIG. 4A shows that the multi-layer structure 102 may include a waveguide 104 and at least one inclined in-guiding channel 106 disposed above the waveguide 104.

[00179] If a cross-section may be taken along B-B of the respective multi-layer structures 102 as shown in FIGs. 3B and 3D, FIG. 4A shows that the multi-layer structure 102 may include a waveguide 104 and at least one inclined out-guiding channel 112 disposed above the waveguide 104.

[00180] FIG. 4B shows a cross-sectional view along A-A of the respective multi-layer structures 102 as shown in FIGs..3C, 3D and 3F or a cross-sectional view along B-B of the respective multi-layer structures 102 as shown in FIGs. 3E and 3F.

[00181] If a cross-section may be taken along A-A of the respective multi-layer structures 102 as shown in FIGs. 3C, 3D and 3F, FIG. 4B shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined in-guiding channel 106 disposed above the waveguide 104 and an in-capping portion 116 disposed above the at * least one inclined in-guiding channel 106.

[00182] If a crossssection may be taken along B-B of the respective multi-layer structures 102 as shown in FIGs. 3E and 3F, FIG. 4B shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined out-guiding channel 112 disposed above the waveguide 104 and an out-capping portion 118 disposed above the at least one inclined out-guiding channel 112.

[00183] FIG. 4C shows a ¢ross-sectional view along A-A of the multi-layer structure 102 as shown in FIG. 3G or a cross-sectional view along B-B of the multi-layer structure 102 as shown in FIG. 3G.

. [00184] If a cross-section may be taken along A-A of the respective multi-layer structures 102 as shown in FIG. 3G, FIG. 4C shows that the multi-layer structure 102 : may include a waveguide 104, at least one inclined in-guiding channel 106 disposed above the waveguide 104 and at least one first active optical element 120 disposed above the at least one inclined in-guiding channel 106.

[00185] If a cross-section may be taken along B-B of the respective multi-layer structures 102 as shown in FIG. 3G, FIG. 4C shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined out-guiding channel 112 disposed above the waveguide 104 and at least one second active optical element 122 disposed above the at least one inclined out-guiding channel 112.

[00186] FIG. 4D shows a cross-sectional view along A-A of the multi-layer structure . 102 as shown in FIG. 3H or a cross-sectional view along B-B of the multi-layer structure 102 as shown in FIG. 3H.

[00187] If a cross-section may be taken along A-A of the respective multi-layer structures 102 as shown in FIG. 3H, FIG. 4D shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined in-guiding channel 106 disposed above the waveguide 104, an in-capping portion 116 disposed above the at least one . inclined in-guiding channel 106 and at least one first active optical element 120 disposed above the in-capping portion 116. : : [00188] - If a cross-section may be taken along B-B of the respective multi-layer structures 102 as shown in FIG. 3H, FIG. 4D shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined out-gniding channel 112 disposed above the waveguide 104, an out-capping portion 118 disposed above the at least one inclined out-gniding channel 112 and at least one second active optical element 122 disposed above the out-capping portion 118. :

[00189] FIG. 4E shows a cross-sectional view along A-A of the multi-layer structure 102 as shown in FIG. 31 or a cross-sectional view along B-B of the multi-layer structure 102 as shown in FIG. 31. : [00190] If a cross-section may be taken along A-A of the respective multi-layer structures 102 as shown in FIG. 3], FIG. 4E shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined in-guiding channel 106 disposed above the waveguide 104, an in-capping portion 116 disposed above the at least one inclined in- guiding channel 106, a first transparent substrate 124 disposed above the in-capping portion 116 and at least one first active optical element 120 disposed above the first transparent substrate 124. - © [00191] If a cross-section may be taken along B-B of the respective multi-layer structures 102 as shown in FIG. 31, FIG. 4E shows that the multi-layer structure 102 may _ include a waveguide 104, at least one inclined out-guiding channel 112 disposed above the waveguide 104, an out-capping portion 118 disposed above the at least one inclined out-gniding channel 112, a second transparent substrate 126 disposed above the out- capping portion 118 and at least one second active optical element 122 disposed above } the second transparent substrate 126. . [00192] FIG. 4F shows a cross-sectional view along A-A of the multi-layer structure 102 as shown in FIG. 37 or a cross-sectional view along B-B of the multi-layer structure 102 as shown in FIG. 31.

[00193} If a cross-section may be taken along A-A of the respective multi-layer structures 102 as shown in FIG. 3J, FIG. 4F shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined in-guiding channel 106 disposed above the waveguide 104, an in-capping portion 116 disposed above the at least one inclined in- guiding channel 106, a first adhesive layer 128 disposed above the in-capping portion 116 and at least one fiist active optical element 120 disposed above the first adhesive layer : 128.7. : 0

[00194] If a cross-section may be taken along B-B of the respective multi-layer structires 102 as shown in FIG. 3J, FIG. 4F shows that the multi-layer structure 102 may include a waveguide 104, at least one inclined out-guiding channel 112 disposed above the waveguide 104, an out-capping portion 118 disposed above the at least one inclined : out-guiding channel 112, a second adhesive layer 130 disposed above the out-capping portion 118 and at least one second active optical element 122 disposed above the second : adhesive layer 130.

[00195] FIG. 4G shows a cross-sectional view along A-A of the multi-layer structure 102 as shown in FIG. 3K or a cross-sectional view along B-B of the multi-layer structure . “~~ 102 as shown in FIG. 3K. :

[00196] If a cross-section may be taken along A-A of the respective multi-layer "structures 102 as shown in FIG. 3K, FIG. 4G shows that the multi-layer structure 102 © may include a device substrate 132, a waveguide 104 disposed above the device substrate 132, at least one inclined in-guiding channel 106 disposed above the waveguide 104, an in-capping portion 116 disposed above the at least one inclined in-guiding channel 106, a first transparent substrate 124 disposed above the in-capping portion 116 and at least one first active optical element 120 disposed above the first transparent substrate 124.

[00197] If a cross-section may be taken along B-B of the respective multi-layer - structures 102 as shown in FIG. 3K, FIG. 4G shows that the multi-layer structure 102 may include a device substrate 132, a waveguide 104 disposed above the device substrate 132, at least one inclined out-guiding channel 112 disposed above the waveguide 104, an out-capping portion 118 disposed above the at least one inclined out-guiding channel 112, a second transparent substrate 126 disposed above the out-capping portion 118 and at least one second active optical element 122 disposed above.the second transparent substrate 126.

[00198] A summary of the sample materials for the respective layers in the multi-layer

CL structure may be as shown in Table 1 below.

Device substrate (132) silicon, polymer, paper, glass, plastic (e.g. acrylic, polyimide, polycarbonate, polyethylene : * | terephthalate, and polyethylene naphthalate). : . aluminium foil, metal sheet, ceramic, a barrier film or a flexible film substrate

Wave-guide (104) polymer materials, metals, metal oxides, electro-opto o "| organic materials and thermal-opto organic materials

Inclined in-guiding channel | polymer materials, metals, metal oxides, electro-opto (106) - | organic materials and thermal-opto organic materials

Inclined out-guiding channel la rr 0000000

Out-capping portion (118)

First transparent substrate (124)/ * | inorganic material, organic material, polymer, glass,

Second transparent substrate | plastic, metal oxide, metal matrix with nanoparticles, (126) silicon dioxide, silicon nitrate, silicon carbide

First active optical element (120)/ | organic material, inorganic material

Second active optical element (122)

Second adhesive layer (130) acetate, epoxy, polyurethane, cyanoacrylate polymers

[00199] FIG. 5A shows a side view of a multi-layer structure 102 including an I-shape waveguide 104, one inclined in-guiding channel 106 and one inclined out-guiding channel 112 according to an embodiment. FIG. 5B shows a top view of the multi-layer . structure 102 as shown in FIG. 5A according to an embodiment. © 7 [00200] The multi-layer structure 102 as shown in FIGs. 5A and 5B may be similar to ~ the multi-layer ‘structure 102 as shown in FIG. 3B except that FIGs. 5A and 5B respectively shows only one inclined in-guiding channel 106 and one inclined out- guiding channel 112 as compared to four inclined in-guiding channels 106 and four inclined out-guiding channels 112 as shown in FIG. 3B.

[00201] The shape or dimension of the I-shape waveguide 104 may vary depending on user and design requirements. Similarly, the number of inclined in-guiding channels 106 and inclined out-guiding channels 112 may vary depending on user and design requirements.

[00202] FIG. 6A shows a side view of a multi-layer structure 102 including an U- shape waveguide 104, one inclined in-guiding channel 106 and one inclined out-guiding channel 112 according to an embodiment. FIG. 6B shows a top view of the multi-layer structure 102 as shown in FIG. 6A according to an embodiment.

[00203] The multi-layer structure 102 as shown in FIGs. 6A and 6B may be similar to the multi-layer structure 102 as shown in FIGs. 5A and 5B-except that FIGs. SA and 5B respectively shows an I-shape waveguide 104 while FIGs. 6A and 6B shows a U-shape waveguide 104. -

[00204] Because of the shape of the U-shape waveguide 104 and the position of the inclined in-guiding channel 106 and inclined out-guiding channel 112, only either the inclined in-guiding channel 106 or the inclined out-guiding channel 112 may be seen from the side view (depending on which side view is adopted by the user). © [00205] Similarly, the shape or dimension of the U-shape waveguide 104 may vary depending on user and design requirements. The number of inclined in-guiding channels 106 and inclined out-guiding channels 112 may also vary depending on user and design requirements.

[00206] In relation to light coupling in, the effectiveness of light being coupled into ~ the waveguide 104 may be strongly related to a first predetermined non-zero angle 108 } (i.e channel angle) of each of the inclined in-guiding channels 106. The first predetermined non-zero angle 108 .may be determined by an incidence angle of the

. inputted light, a refractivé index (RI) of the material of the inclined in-guiding channel 106 and the material of the waveguide 104.

[00207] The first predetermined non-zero angle 108 (i.e. inclined channel angle) shall only be modulated within a certain angle range, in order to obtain a high effectiveness of light being coupled into the waveguide 104, it may be preferred to maximize a width ratio of the projection of the inclined wall (Wy) to the overall light coupled in the region (Wj). ie. max EW/W).

[00208] Several approaches may be adopted, one example is to increase the number of inclined in-guiding channels 106 (i.e. inclined channels) by reducing the width of the gap between the respective inclined in-guiding channels. 106, and decrease the width of the inclined in-guiding channel 106 while keeping the projected width of the inclined in- guiding channel 106 (ie. inclined wall) unchanged. Keeping the projected width (Pj) of : the inclined in-guiding channels 106 unchanged may be equivalent to keeping the inclined channel] angle constant. It might be beneficial to notice that such gap should still be big enough not to introduce interference. .[00209] In addition, the depth (d;) of the inclined in-guiding channel 106 shall be + sufficient such that the light ray from the first active optical element 120 (i.e. light : source) may be reflected at least one time at an inclined reflected wall of the inclined in- guiding channel: 106. It may be preferred for reflected light ray from the inclined in- + guiding channel 106 to move in a forward direction in the waveguide 104, towards the inclined out-guiding channel (i.e. meaning the reflected light ray travels along the waveguide 104 towards the inclined out-guiding channel 112).

[00210] To avoid light coupled in from escaping from the other inclined in-guiding channel 106 (i.e. channels), several approaches may be adopted and may be explained below. :

[00211] One approach as shown in FIG. 7 may be to consider the plurality of inclined in-guiding channels 106 as one single region to determine the overall width (W;) of the plurality of inclined in-guiding channels 106. ; : [00212] FIG. 7 shows a side view of a multi-layer structure 102 including a plurality of inclined in-guiding channels 106, the plurality of inclined in-guiding channels 106 “being considered as a single region according to an embodiment.

[00213] The reflected light which may be coupled in by the first inclined in-guiding channel 106 of the plurality of inclined in-guiding channels 106 may hit a location along a surface on the same side as the inclined in-guiding channel 106 of the waveguide 104 after the last inclined in-guiding channel 106 of the plurality of inclined in-guiding channels 106 by careful calculation, therefore the coupled-in light may not be lost.

[00214] The width (W;) of the plurality of inclined in-guiding channels 106 (i.e. . overall light in-coupling structure) may be determined by the incidence angle of the light which may be coupled into the waveguide 104 through the plurality of inclined in- guiding channels 106; the depth of the waveguide 104 and the RI of the material of the waveguide 104. :

[00215] The depth of the waveguide 104 may be represented by dwe.

[00216] The pitch and the distribution of the individual inclined in-guiding channel 106 (i.e. inclined light coupled channel) may not be as critical in this approach and this approach may be suitable for a thick waveguide 104. :

: [00217] FIG. 8 shows a side view of a multi-layer structure 102 including a plurality of inclined in-guiding channels 106, each of the plurality of inclined in-guiding channels 106 being considered individually according to an embodiment.

[00218] The approach as shown in FIG. 8 may be to consider the pitch and location of the individual inclined in-gniding channel 106 (i.e. inclined ¢oupled in channel).

[00219] By carefully calculating the light path such that the most of the reflected light : may only hit the downstream gap locations (e,g, Gil) between the respective inclined in- guiding channels 106, the pitch and thus location of the individual inclined in-guiding channel 106 may be designed for minimising loss of light coupling into the waveguide 104.

[00220] The pitch and the distribution of the individual inclined in-gniding channel : 106 may be determined by the incidence angle of the light coupled into the waveguide 104, the depth of the waveguide 104 and the RI of the material of waveguide 104. The pitch and the distribution of the individual inclined in-guiding channel 106 may be _ uniform, periodical, or non-uniform. This approach may be suitable for a relatively thin © + waveguide 104. : © [00221] © FIG. 9 shows a side view of a multi-layer structure 102 including a wavegtide 104, a plurality of inclined in-guiding channels 106 and an in-capping portion 116 according to an embodiment. : [00222] The approach as shown in FIG. 9 may be to include the in-capping portion 116 on top of the inclined in-guiding channels 106. The in-capping portion 116 (i.e. capping layer) may be flat, or may include some structures which may enhance the light coupling effect. For example, the in-capping portion 116 may include a convex or concave shape at the gap region (Gii, Go, Gis) between two respective inclined in-guiding channels 106 or the in-capping portion 116 may include a micro lens structure which may assist the focusing of light.

[00223] Some potential advantages may be provided by including an in-capping portion 116. Firstly, the inclusion of the in-capping portion 116 may provide a relatively : flat surface over the respective top surfaces of the plurality of inclined in-guiding channels 106. This may facilitate downstream processes, such as deposition of organic light transmissive devices during monolithically integration process. Secondly, the in- capping portion 116 may allow the sealing of non-solid cladding materials (gas, liquid; eg: air, water) for light coupling. If the cladding material are non-solid, it is possible that the non-solid cladding material will leak if there is no capping layer. However if there exist a capping layer, the non-solid cladding material is thus sealed and no leakage will occur.. The in-capping portion 116 futher provides protection like a barrier, for the - subsequent active optical elements deposited thereon, preventing oxidation resulted by . humidity.

[00224] Thirdly, the in-capping portion 116 may serve to enhance efficiency of light coupling into the waveguide 104. The in-capping portion 116 may change the incident ~ anglé of the inputted light. For example, if there may be a grating at the in-capping portion 116 or if the in-capping portion 116 may provide a function similar to a polarizer _ or if there are nano or micro structures at a surface of the in-capping portion 116 for example by naro-imprinting, preferably on the opposite surface of the active optical elements so as to provide a flat top surface for the active optical elements. The in-capping portion 116 may also serve to guide the light initially illuminated to or above the gap

. region between the respective inclined in-guiding channels 106 to the inclined in-guiding channels 106 subsequently, thereby resulting in a better light coupling effect.

[00225] Further, if there may be a concave or convex surface at the gap region, the incident angle of light may also. change which may provide a more favorable incident angle at the inclined in-guiding channels 106, thereby resulting in better light coupling-in effect. A smooth and continuous convex, concave or planar surface on the side of the : active optical elements is preferred as a result of downstream processing for active optical elements during monolithically integration process.

[00226] Even further, the in-capping portion 116 may allow the concentration of more light to the inclined in-guiding channel 106 thereby achieving a better light coupling-in effect. For example, if the in-capping portion 116 may include a micro lens structure. : [00227] Next, the in-capping portion 116 may modulate the optical characteristic of the input light. For example, if the in-capping portion 116 may include an optical filter function, only the light within certain wavelength range may be inputted to the inclined ~° in-guiding channel 106 and therefore propagated in the waveguide 104. ~~ .. [00228] FIG. 10A shows a side view of a multi-layer structure 102 including a "waveguide 104, two inclined in-guiding channels 106 and an in-capping portion 116 with 3 two plane surfaces 134 according to an embodiment.

[00229] FIG. 10A shows a light propagation diagram showing the in-capping portion 116 guiding the light initially illuminated to the gap region between the respective inclined in-guiding channels 106 to the inclined in-guiding channels 106 subsequently, thereby resulting in a better light coupling effect. The angle of incidence and refractive index plays a role herein for refraction and total internal reflection.

[00230] FIG. 10B shows a side view of a multi-layer structure 102 including a waveguide 104, two inclined in-guiding channels 106 and an in-capping portion 116 with one curved portion 136 pointing away from the waveguide 104 according to an embodiment; FIG. 10C shows a side view of a multi-layer structure 102 including a waveguide 104, two inclined in-guiding channels 106 and an in-capping portion 116 with two curved portions 136 pointing away from the waveguide 104 according to an embodiment; FIG. 10D shows a side. view of a multi-layer structure 102 including a - waveguide 104, two inclined in-guiding channels 106 and an in-capping portion 116 with two curved portions 138 pointing towards the waveguide 104 according to an embodiment. : .. [00231] The curved portion 136 pointing away from the waveguide 104 or curving into the in-capping portion 116 may be termed a “concave” portion and the curved "portion 138 pointing towards the waveguide 104 or curving out of the in-capping portion 116 may be termed a “convex” portion. FIGs. 10B to 10D shows that if there . may be a concave portion 136 or convex portion 138 within the in-capping portion 116 above the gap region between the respective inclined in-guiding channels 106, the incident angle of light may also change which may provide a more favorable incident angle at the inclined in-guiding channels 106, thereby resulting in an improved coupling efficiency. In FIG. 10B, there may be a possibility that parts of the light may violate total ~ internal reflection (TIR), however, the design of the concave portion or curved surface 136 does compensate for the light losses of the violation. The concave portion or curved surface 136 is designed to enhance light coupling efficiency into the next inclined in- guiding channel 106.

: [00232] The initial angle of light initially incident on the respective concave portion 136 and convex portion 138 of the in-capping portion 116 in FIGs. 10B to 10D may be termed as ©; and the subsequent angle of light subsequently incident on the inclined in- guiding channel 106 may be termed as ©,. In FIGs. 10B-to 10D, the initial angle (1) may be taken from a vertical surface as shown. And, in FIGs. 10B to 10D, the subsequent angle (02) may also be taken from a further vertical surface as shown. :

[00233] As a further example, FIGs. 10B, 10C and 10D shows that ©,# ©2.

[00234] The light rays (for example T; (lowest mode), Ti1, Tis2, Titn, Tirnr1 (highest mode) as shown within the waveguide 104 in each of FIGs. 10B to 10D may be the : different propagation modes of the light. : [00235] In relation to light coupling out, to maximize the efficiency of light coupling : out and to make the direction of the light coupling out closer to a direction substantially perpendicular to waveguide 104, the following design references may be adopted for example. FIG. 11 shows a side view of a multi-layer structure 102 including a waveguide 104 and four inclined out-guiding channels 112 according to an embodiment. ~ [00236] Each of the four inclined out-guiding channels 112 may be optically coupled to the waveguide 104 and inclined. at a second predetermined non-zero angle 114 to the ©. surface110 of the waveguide 104. . © [00237] As an example, FIG. 12A shows a side view of a multi-layer structure 102 - including a waveguide 104 and four inclined out-gniding channels 112 for use in a first scenario according to an embodiment and FIG. 12B shows a side view of a multi-layer structure 102 including a waveguide 104 and four inclined out-guiding channels 112 for use in a second scenario according to an embodiment.

[00238] In all of FIGs. 11, 12A and 12B, the respective second predetermined non- zero angle 114 (8,1, O02, O03, Bos) or the inclined angle of each of the four inclined out- - guiding channels 112 may be determined by the original highest and lowest modes for the light ray emitted from each of the four inclined out-guiding channels 112.

[00239] For example, as shown in FIGs. 12A and FIG. 12B, for a first inclined out- : guiding channel 112 (i.e. with second predetermined non-zero angle 114 (6,1), the highest and lowest modes may be Tintm and Tin respectively. Moreover it may be : preferred that the second predetermined non-zero angle 114 of each of the four inclined out-guiding channels 112 may include a relationship such that Bo; 265 2643 2004. The higher the optical mode, the smaller the incidence angle, thus a larger inclined channel angle is preferred for the channel for higher mode (i.e. the upstream inclined channel).

Therefore, it is preferred that 6, =0,;,

[00240] Further, in all of FIGs. 11, 12A and 12B, the depth (do) of the respective four inclined out-guiding channels 112 shall be sufficiently sized so as to confirm that all the - light rays may be reflected at the respective inclined wall of each of the four inclined out- guiding channels 112. :

[00241] In addition, in all of FIGs. 11, 12A and 12B, the respective width (Wo1, Wop,

Ws, Waa) of each of the four inclined out-guiding channels 112 may be determined by the original highest and lowest modes for the light ray emitted from each of the inclined out- guiding channels 112. Co

[60242] For example, as shown in FIGs. 12A and FIG. 12B, for the first inclined out- guiding channel 112 (i.e. with width Wy; ), the highest and lowest modes may be Tinim and Tj, respectively. Moreover it may be provided that the respective width of each of the inclined out-guiding channels 112 may include a relationship such that Wy; <Wg,; <

Wos <Wos. to

[00243] In addition, in all of FIGs. 11, 12A and 12B, the overall width (Wo) of the four inclined out-guiding channels 112 may be determined by the depth (dwg) of the waveguide 104, the highest propagation mode (the light ray with smallest incidence angle), the lowest propagation mode (the light ray with largest incidence angle) inside the . waveguide 104 (i.e. Tinim and Tj respectively), and refractive index of four inclined out- guiding channels 112. :

[00244] Finally, in FIG. 12A, the width (Gor <Go2 <Gos) of the respective individual gap between the inclined out-guiding channels 112 may be determined by the original lowest mode at the previous inclined channel and the original highest mode at the : following inclined channel (for example: For Go, the original lowest mode and the original highest mode may be Tim and Tie respectively). Moreover, the width of the respective individual gaps maybe configured such that the width of the respective individual gaps ‘include a relationship such that Goi <Ge2 =Gos. This relation of the width of the respective individual gap (Goi <Go2 <Gos) is more related to the thickness of waveguide 104, in particular for a multimode waveguide 104, and the size of photosensitive area of a photo detector (e.g. large for OPD). One of the advantages of using a large photo detector is that no precise alignment is needed to align the photo detector to the inclined out-guiding channels 112.

[00245] - In the first scenario as shown in FIG. 12A, mode coupling and/or energy redistribution does not happen or may not be significant after a portion of the light may be respectively coupled out from each of the four inclined out-guiding channels 112. The first scenario may occur for a relatively thick waveguide and for a point light source for example.

[00246] In the second scenario as shown in FIG. 12B, mode coupling and/or energy redistribution may happen after a portion of light may be respectively coupled out from each of the four inclined out-guiding channels 112. The second scenario may occur for a ; relatively thin waveguide and for a planar light source for example. In some situations (for example thin waveguide and: planar light source), energy redistribution and/or mode - coupling between different optical propagation modes may happen for the light not coupling out from the previous inclined out-guiding channels 112. There may be light remaining at waveguide 104 after the previous inclined out-gniding channel 112. The - remaining light will therefore undergo energy redistribution or mode coupling and form similar mode profile as that of the initial mode profile.

[00247] In such a scenario, the respective second predetermined non-zero angle 114 (801, Boz, Bo3, Bos) Or the inclined angle of inclined out-guiding channels 112 may be . determined by the original highest and lowest modes for the light ray. Further, the depth (do) of the respective inclined out-guiding channels 112 shall be sufficiently sized so as to confirm that the light rays may be reflected at the respective inclined wall of the inclined out-guiding channels 112. In addition, the respective width of the four inclined out- guiding channels 112 may be determined by the original highest and lowest modes for the light ray emitted from the inclined out-guiding channels 112.

[00248] Increasing the number of the inclined out-guiding channel 112, increasing the width of the inclined out-guiding channel 112 and decreasing gap width may enhance

: coupling out efficiency (while the design reference for depth of the inclined out-guiding channel 112 to have at least one reflection within the inclined wall may still apply).

[00249] FIG. 13 shows a flow-chart 1310 of a method of forming a multi-layer structure 102 according to an embodiment.

[00250] The method of forming a multi-layer structure 102 may start in step 1311 by forming a waveguide 104.

[00251] Next in step 1312, the method may include forming at least one inclined in- guiding channel 106 on the waveguide 104 such that the at least one inclined in-guiding channel 106 may be optically coupled to the waveguide 104 and inclined at a first predetetmined non-zero angle 108 to a surface 110 of the waveguide 104. . [00252] In step 1313, the at least one inclined in-guiding channel 106 may be configured to receive light and to direct the light to the waveguide 104 such that the light may travel within the at least one inclined in-guiding channel 106 by means of reflection into the waveguide 104. :

[00253]. As an embodiment, before forming the waveguide 104 in step 1311, the method of forming the multi-layer structure 102 may start with forming the waveguide 104 on a device substrate 132 and then involving an additional pre-step of attaching the device substrate 132 to a supporting substrate, if necessary.

[00254] FIG. 14A and 14B show respective flow-charts 1410 and 1420 with various possible methods of attaching a device substrate 132 to a supporting substrate.

[00255] FIG. 14A shows a flow-chart 1410 of an energy-assisted method of attaching a device substrate 132 to a supporting substrate according to an embodiment without having an intermediate adhesive layer.

[00256] The energy-assisted method may start in step 1411 by cleaning and conditioning of a supporting substrate. However, step 1411 may also be optional if the supporting substrate may already be pre-cleaned or pre-conditioned.

[00257] Next in step 1412, the method may include physically contacting a device substrate 132 with the supporting substrate to form an assembly.

[00258] Then in step 1413, the method may include heating up and illuminating of the assembly under electromagnetic energy to bond the device substrate 132 and the supporting substrate together.

[00259] In step 1414, the resultant assembly may include the device substrate 132 and the supporting substrate.

[00260] FIG. 14B shows a flow-chart 1420 of a method of attaching a device substrate 132 to a supporting substrate according to an embodiment having an intermediate - adhesive layer.

[00261] The energy-assisted method may start in step 1421 by cleaning and conditioning of a supporting substrate. However, step 1421 may also be optional if the supporting substrate may already be pre-cleaned or pre-conditioned. [00262) Next in step 1422, the method may include physically contacting an adhesive surface on a device substrate 132 with the supporting substrate to form an assembly.

[00263] Then in step 1423, the method may include applying pressure, heating up or illuminating the assembly under electromagnetic energy to bond the device substrate 132 and the supporting substrate together. ;

. [00264] In step 1424, the resultant assembly may include the device substrate 132 and the supporting substrate. :

[00265] FIG. 15 shows a flow-chart 1510 of a method of forming an anti-refraction coating (ARC) on a device substrate 132 according to an embodiment.

[00266] The method of forming the ARC on the device substrate 132 may start in step 1511 where the component may be generated from a previous step.

[00267] Next in step 1512, the method may include cleaning, or cleaning followed by conditioning. However, step 1512 may also be optional.

[00268] Then in step 1513, the method may include depositing ARC materials on the device substrate 132.

[00269] Further in step 1514, the method may include coating of the ARC materials. : [00270] Then in step 1515, the method may include baking at a temperature of between about 50 celsius to about 250 celsius, depending on the material used. a [00271] FIG.'16A shows a flow-chart 1610 of a method of forming a waveguide 104, : the method involving photolithography according to an embodiment.

[00272] The method of forming the waveguide 104 may start in step 1611, wherein the component may be generated from a previous step.

[00273] Next in step 1612, the method may include cleaning, or cleaning followed by conditioning. However, step 1612 may be optional. © [00274] Then in step 1613, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1613 may also be optional.

[00275] Further in step 1614, the method may include coating of waveguide (WG) 104 materials. This may be followed by baking in step 1615. Then in step 1616, ultra-violet (UV) exposure may be carried out. Further, in step 1617, post exposure bake may be carried out. However, step 1617 may also be optional.

[00276] This may be followed by developing in step 1618. Then in step 1619, baking may be carried out. However, the step 1619 may also be optional. : [00277] In step 1620, the method may include repeating the steps of 1612 to 1619 for a multi-layer structure 102 including multiple layers of waveguide 104 or a multi-layer WG structure.

[00278] FIG. 16B shows a flow-chart 1620 of a method of forming a waveguide 104, the method involving imprinting according to an embodiment.

LL [00279] The method of forming the waveguide 104 may start in step 1621, wherein the component may be generated from a previous step.

[00280] Next in step 1622, the method may include cleaning, or cleaning followed by conditioning. However, step 1622 may also be optional. . [00281] Then in step 1623, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1623 may also be optional. ' [00282] Further in step 1624, the method may include coating of waveguide materials.

This may be followed by baking in step 1625. Then in step 1626, imprinting by UV . cured or thermal cured may be carried out. Further, in step 1627, baking may be carried out. However, the step 1627 may also be optional.

: [00283] In step 1628, the method may include repeating the steps of 1622 to 1627 for a multi-layer structure 102 including multiple layers of waveguide 104 or a multi-layer WG structure. '

[00284] FIG.16C shows a flow-chart 1630 of a method of forming a waveguide 104, the method involving hot embossing or thermal compression according to an embodiment. :

[00285] The method of forming the waveguide 104 may start in step 1631, wherein the component may be generated from previous steps.

[00286] Next in step 1632, the method may include cleaning, or cleaning followed by conditioning. However, step 1632 may also be optional. . [00287] Then in step 1633, the method may include depositing an adhesion promoting : layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1633 may also be optional. * [00288] Further in step 1634; the method may include coating of waveguide 104 materials, This may be followed by baking in step 1635. Then in step 1636, hot embossing or thermal compression may be carried out. Further, in step 1637, baking may be carried out. However, the step 1637 may also be optional.

[00289] In step 1638, the method may include repeating the steps of 1632 to 1637 for a multi-layer structure 102 including multiple layers of waveguide 104 or a multi-layer WG structure. .

[00290] FIG. 16D shows a flow-chart 1640 of a method of forming a waveguide 104, the method involving molding according to an embodiment.

[00291] The method of forming the waveguide 104 may start in step 1641 by installing and closing a waveguide mold in a mold cavity of an injection machine. © [00292] Next in step 1642, the method may include feeding a polymer waveguide raw "material to a feeder of the injection machine.

[00203] Then in step 1643, the method may include heating up to melt the polymer waveguide raw material. ; : [00294] Further in step 1644, the method may include injecting the molten polymer waveguide raw material to the waveguide mold under pressure.

[00295] This may be followed by cooling down of the molten polymer waveguide and the waveguide mold in step 1645.

[00296] Then in step 1646, the waveguide mold may be opened and the waveguide 104 may be ejected.

[00297] FIG. 17A shows a flow-chart 1710 of a method of forming an inclined in- guiding channel 106 or an inclined out-gniding channel 112, the method involving an inclined UV exposure according to an embodiment. . [00298] The method of forming the inclined in-guiding channel 106 or inclined out- guiding channel 112 may start in step 1711, wherein the component may be generated froma previous step. © : © [00299] Next in step 1712, the method may include cleaning, or cleaning followed by conditioning. However, step 1712 may be optional. . [00300] Then in step 1713, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1713 may also be optional.

: [00301] Further in step 1714, the method may include coating of inclined in-guiding channel or inclined out-guiding channel materials. The inclined in-guiding channel or inclined out-guiding channel materials may be of the same or different material.

[00302] This may be followed by baking in step 1715. Then in step 1716, an inclined

UV exposure may be carried out. The inclined UV exposure may mean that the UV exposure may be carried out at an inclined angle relative to the device substrate 132.

[00303] Further, in step 1717, post exposure baking may be carried out. The step 1717 may also be optional.

[00304] In step 1718, a developing step may be carried out. This may be followed by baking in step 1719. However, the step 1719 may also be optional.

[00305] FIG. 17B shows a flow-chart 1720 of a method of forming an inclined in- . guiding channel 106 or an inclined out-guiding channel 112, the method involving laser excitation or laser writing according to an embodiment. . [00306] The method of forming the inclined in-guiding channel 106 or inclined out- guiding channel 112 may start in step 1721, wherein the component may be generated from a previous step.

[00307] Next in step 1722, the method may include cleaning, or cleaning followed by conditioning. However, step 1722 may be optional. :

[00308] Then in step 1723, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning. However, step 1723 may also be optional.

[00309] Further in step 1724, the method may include coating of inclined in-guiding channel or inclined out-guiding channel materials. The inclined in-guiding channel or inclined out-guiding channel materials may be of the same or different material.

[00310] This may be followed by baking in step 1725. Then in step 1726, an UV laser - excitation or laser writing may be carried out. The UV laser excitation or laser writing may be carried out by either inclining the entire assembly 101 (i.e. a supporting substrate 103, a device substrate 132, an ARC 105, a waveguide 104, an inclined in-guiding : : channel layer 142 or an inclined out-guiding channel layer 144) or by inclining the laser ray. Further details of the UV laser excitation may be disclosed in FIGs. 17B’ and 17B’.

[00311] Further, in step 1727, post exposure baking may be carried out. The step 1727 may also be optional. . [00312] In step 1728, a developing step may be carried out. This may be followed by _ baking in step 1729. However, the step 1729 may also be optional.

[00313] FIG. 17B’ shows a laser source 140 positioned at a first position relative to a device substrate 132 according to an embodiment and FIG. 17B’’ shows a laser - source 140 positioned at a second position relative to a device substrate 132 according to . an embodiment.

[00314] An inclined laser ray may be achieved by directly inclining a laser head of the laser soirce 140 or may be achieved by changing the direction of the laser ray from the laser head through a scan head and/or lens.

[00315] In both FIGs. 17B’ and 17B”, an inclined in-guiding channel layer 142 or an . inclined out-guiding channel layer 144 may be positioned on the previously formed components 107 which may include the supporting substrate 103, the device substrate 132, the ARC 105 and the waveguide 104. The laser ray from the laser source 140 may : substantially shine into the inclined in-guiding channel layer 142 or the inclined out-

: guiding channel layer 144, thereby forming the inclined in-guiding channel (not shown) or inclined out-guiding channel (not shown). ~ [00316] Further, in both FIGs. 17B” and 17B”, the energy may be directly illuminated to the inclined in-guiding channel layer 142 or the inclined out-guiding channel layer 144 (from the front surface), but will not affect or create changes to previously formed components 107 as the materials have been polymerized (stable/done). In this regard, the waveguide 104 will not be affected by the laser exposure.

[00317] In FIG. 17B’, inclined in-guiding channel layer 142 or the inclined out- guiding channel layer 144 on the previously formed components 107 may be inclined relative to the laser source 140 while in FIG. 17B”, the laser source 140 may be inclined : relative to the inclined in-guiding channel layer 142 or the inclined out-guiding channel : layer 144 on the previously formed components 107.

[00318] FIG.17C shows a flow-chart 1730 of a method of forming an inclined in- guiding: channel 106 or an inclined out-guiding channel 112, the method involving imprinting according to an embodiment. :

[00319] The method of forming the inclined in-guiding channel 106 or inclined out- guiding channel 112 may start in step 1731, wherein the component may be generated from a previous step.

[00320] Next in step 1732, the method may include cleaning, or cleaning followed by - conditioning. However, step 1732 may be optional. :

[00321] Then in step 1733, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1733 may also be carried out if necessary.

[00322] Further in step 1734, the method may include coating of light in-coupling or light out-coupling materials. The light in-coupling or light out-coupling materials may be - of the same or different material.

[00323] This may be followed by baking in step 1735. Then in step 1736, imprinting by UV-cured or thermal cured may be carried out. This may be followed by baking in ; : step 1737. However, the step 1737 may also be optional.

[00324] FIG. 17D shows a flow-chart 1740 of a method of forming an inclined in- - guiding channel 106 or an inclined out-guiding channel 112, the method involving hot embossing or thermal compression according to an embodiment.

[00325] The method of forming the inclined in-guiding channel 106 or inclined out- oo guiding channel 112 may start in step 1741, wherein the component may be generated from a previous step. © [00326] Next in step 1742, the method may include cleaning, or cleaning followed by conditioning. However, step 1742 may be optional. . [00327]. Then in step 1743, the method may include depositing an adhesion promoting : layer, or depositing an adhesion - promoting layer and followed by conditioning.

However, step 1743 may also be optional.

[00328]. Further in step 1744, the method may include coating of inclined in-guiding channel layer 142 or the inclined out-guiding channel layer 144 materials. The inclined . in-guiding channel layer 142 or the inclined out-guiding channel layer 144 materials may be of the same or different material.

: [00329] This may be Followed by baking in step 1745. Then in step 1746, hot embossing or thermal compression may be carried out. This may be followed by baking _ instep 1747. However, the step 1747 may also be optional.

[00330] FIG. 17E shows a flow-chart 1750 of a method of forming an inclined in- guiding channel 106 or an inclined out-guiding channel 112 together with waveguide 104, the method involving molding, for example injection molding according to an embodiment.

[00331] The method of forming the waveguide 104, the inclined in-guiding channel 106 and the inclined out-guiding channel 112 may start in step 1751 by installing and closing a waveguide and light coupling mold in a mold cavity of an injection machine.

[00332]. Next in step 1752, the. method may include feeding a polymer waveguide and : light coupling raw material to a feeder of the injection machine.

[00333] Then in step 1753, the method may include heating up to melt the polymer waveguide and light coupling raw material.

[00334] Further in step 1754, the method may include injecting the molten polymer waveguide and light coupling raw material to the waveguide and light coupling mold under pressure.

[00335] This may be followed by cooling down of the molten polymer, and the mold in step 1755.

[00336] Then in step 1756, the waveguide and light coupling mold may be opened and the waveguide 104 with the inclined in-guiding channel 106 and/or inclined out-guiding channel 112 may be ejected.

[00337] FIG. 18A shows a flow-chart 1810 of a method of forming an in-capping portion 116 or an out-capping portion 118, the method involving ultra-violet exposure of an existing layer according to an embodiment. :

[00338]: The method of forming the in-capping portion 116 or the out-capping portion 118 may start in step 1811 by UV exposure with reduced energy dosage by partial exposure or gray mask for example of the existing layer. The existing layer may include : the inclined in-guiding channel layer 142 or the inclined out-guiding channel layer 144 previously deposited to form the inclined in-guiding channel 106 or the inclined out- - guiding channel 112.

[00339] Next in step 1812, the method may include post exposure bake. However, the step 1812 may be optional.

LL [00340] In 1813, the method may include developing.

[00341] This may be followed by baking in step 1814. However, the step 1814 may "also be optional. ~

[00342] FIG. 18B shows a flow-chart 1820 of a method of forming an in-capping .. portion-116 or an out-capping portion 118, the method involving depositing and ultra- violet exposure of an additional layer according to an embodiment.

[00343] The method of forming the in-capping portion 116 or an out-capping portion 118 may start in step 1821, wherein the component may be generated from previous steps. . [00344] Next in step 1822, the method may include cleaning, or cleaning followed by "conditioning. However, step 1822 may also be optional. oC

. [00345] Then in step 1823, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning. However, step 1823 may also be optional.

[00346] Further in step 1824, the method may include coating of the additional layer, which may include an in-capping layer or an out-capping layer. This may be followed by baking in step 1825. Then in step 1826, ulira-violet (UV) exposure with a reduced energy dosage by partial exposure or gray mask for example may be carried out. Further, in step 1827, post exposure bake may be carried out. However, step 1827 may also be optional.

E [00347] This may be followed by developing in step 1828. Then in step 1829, baking : may be carried out. The step 1829 may also be optional.

[00348] FIG. 18C shows a flow-chart 1830 of a method of forming an in-capping . portion. 116 or an out-capping portion 118, the method involving an additional transparent substrate with an additional unexposed layer according to an embodiment.

[00349] The method of forming the in-capping portion 116 or an out-capping portion 118 may start in step 1831 with providing a transparent substrate or a substrate with a first active optical element 120 or second active optical element 122 (i.e. a light transmissive device) at the backside.

[00350] Next in step 1832, the method may include cleaning, or cleaning followed by conditioning. However, step 1832 may also be optional.

[00351] Then in step 1833, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning. However, step 1833 may also be optional.

[00352] Further in step 1834, the method may include coating of an in-capping layer or an out-capping layer. This may be followed by baking in step 1835.

[00353] FIG. 18D shows a flow-chart 1840 of a method of forming an in-capping - portion 116 or an out-capping portion 118, the method involving photolithography for an additional transparent substrate with an additional layer according to an embodiment.

[00354] The method of forming the in-capping portion 116 or an out-capping portion ; : 118 may start in step 1841 with providing a transparent substrate or a substrate with a first active optical element 120 or second active optical element 122 (i.e. an organic light * transmissive device) at the backside. ’

[00355] Next in step 1842, the method may include cleaning, or cleaning followed by conditioning. However, step 1842 may be optional.

[00356] Then in step 1843, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1843 may also be optional. :

[00357] Further in step 1844, the method may include coating of an in-capping layer . or an out-capping layer. This may be followed by baking in step 1845.

[00358] Then in step 1846, ultra-violet (UV) exposure with a sufficient or a reduced energy dosage may be carried out. Further, in step 1847, post exposure bake may be carried out. However, step 1847 may also be optional. : :

[00359] This may be followed by developing in step 1848. However, step 1848 may . also be optional.

[00360] Then in step 1849, baking may be carried out. The step 1849 may also be optional.

: [00361] FIG. 18E shots a flow-chart 1850 of a method of forming an in-capping portion 116 or an out-capping portion 118, the method involving imprinting on an additional transparent substrate according to an embodiment. [00362) The method of forming the in-capping portion 116 or an out-capping portion 118 may start in step 1851 with providing a transparent substrate or a substrate with a first active optical element 120 or second active optical element 122 (i.e. an organic light transmissive device) at the backside.

[00363] Next in step 1852, the method may include cleaning, or cleaning followed by "conditioning. However, step 1852 may also be optional.

[00364] Then in step 1853, the method may include depositing an adhesion promoting - layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1853 may also be Optional. " [00365]. Further in step 1854, the method may include coating of an in-capping layer or an out-capping layer. This may be followed by baking in step 1855.

[00366] Then in step 1856, imprinting with UV cured or thermal cured with sufficient or reduced energy dosage may be carried out.

[00367] This may be followed by developing in step 1857. However, step 1857 may also be optional.

[00369] FIG. 18F shows a flow-chart 1860 of a method of forming an in-capping portion 116 or an out-capping portion 118, the method involving hot embossing or thermal compression according to an embodiment.

[00370] The method of forming the in-capping portion 116 or an out-capping portion 118 may start in step 1861 with providing a transparent substrate or a substrate with a - first active optical element 120 or second active optical element 122 (i.e. a light transmissive device) at the backside.

[00371] Next in step 1862, the method may include cleaning, or cleaning followed by ; : conditioning. However, step 1862 may also be optional.

[00372] Then in step 1863, the method may include depositing an adhesion promoting layer, or depositing an adhesion promoting layer and followed by conditioning.

However, step 1863 may also be optional.

[00373] Further in step 1864, the method may include coating of an in-capping layer or an out-capping layer. This may be followed by baking in step 1865.

[00374] Then in step 1866, hot embossing or thermal compression may be carried out.

[00375] Then in step 1867, baking may be carried out. The step 1867 may also be optional. . [00376] FIG. 18G shows a flow-chart 1870 of a method of forming an in-capping portion: 116 or an out-capping portion 118, the method involving molding according to an embodiment. :

[00377] The method of forming the in-capping portion 116 or an out-capping portion 118 may start in step 1871 by installing and closing a cap mold in a mold cavity of an - injection machine.

[00378] Next in step 1872, the method may include feeding a cap raw material to a feeder of the injection machine. :

: [00379] Then in step 1873, the method may include heating up to melt the cap raw material.

[00380] Further in step 1874, the method may include injecting the molten cap raw : material to the cap mold under pressure.

[00381] This may be followed by cooling down of the molten cap and cap mold in step 1875. :

[00382] Then in step 1876, the cap mold may be opened and the in-capping portion 116 and/or out-capping portion 118 may be ejected.

[00383] FIG. 19A shows a flow-chart of an energy-assisted method of detaching a device substrate 132 from a supporting substrate 103 according to an embodiment.

[00384] In step 1911, standalone components or completed multi-layer structures 102 . © attached on a supporting substrate 103 forming an assembly may be provided.

[00385] Then in step 1912, the assembly may be heated up or illuminated under electromagnetic energy (for example if the supporting substrate 103 may be bonded with the standalone components or completed multi-layer structures 102 through thermal- release. adhesive or UV-release adhesive respectively) to release the bonding between the supporting substrate 103 and the standalone components or completed multi-layer structures 102.

[00386] In step 1913, the standalone components or completed multi-layer structures 102 may be formed.

[00387] FIG. 19B shows a flow-chart 1920 of a mechanical method of detaching a device substrate 132 from a supporting substrate 103 according to an embodiment.

[00388] In step 1921, standalone components or completed multi-layer structures 102 attached on a supporting substrate 103 forming an assembly may be provided.

[00389] Then in step 1922, the supporting substrate 103 may be mechanically peeled off or tore off from the assembly.

[00390] In step 1923, the standalone components or completed multi-layer structures 102 may be formed. : [00391] While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.

Claims

Claims What is claimed is:

1. A multi-layer structure comprising: a waveguide; a plurality of inclined in-guiding channels optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide; and an in-capping portion disposed above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in-guiding channels of the plurality of inclined in-guiding channels, and wherein the in-capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide.

2. The multi-layer structure of claim 1, further comprising at least one inclined out- guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide.

3. The multi-layer structure of claim 2, wherein the at least one inclined out-guiding channel is configured to direct the light out of the waveguide such that the light exiting the waveguide travels within the at least one inclined out-guiding channel.

4. The multi-layer structure of claim 3 , further comprising at least one inclined out- guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; and an out-capping portion disposed above the at least one inclined out-guiding channel, wherein the out- capping portion includes at least one planar surface.

5. The multi-layer structure of claim 4, wherein the in-capping portion is the same or different from the out-capping portion.

6. The multi-layer structure of any one of claims 1 to 5, further comprising at least one first active optical element disposed above the plurality of inclined in-guiding channels.

7. The multi-layer structure of claim 6,wherein the at least one first active optical element is disposed above the in-capping portion.

8. The multi-layer structure of claim 6 or 7, wherein the at least one first active optical element comprises at least one light source configured to provide the light.

9. The multi-layer structure of any one of claims 2 to 8, further comprising at least one inclined out-guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; and at least one second active optical element disposed above the inclined out-guiding channel.

10. The multi-layer structure of claim 9, further comprising an out-capping portion disposed above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface, wherein the at least one second active optical element is disposed above the out-capping portion.

11. The multi-layer structure of claim 9 or 10, wherein the at least one second active optical element comprises at least one photo detector.

12. The multi-layer structure of any one of claims 1 to 11, wherein each of the plurality of inclined in-guiding channels is inclined at the same or different first predetermined non-zero angle from another of the plurality of inclined in-guiding channels.

13. The multi-layer structure of any one of claims 1 to 12, wherein each of the plurality of inclined in-guiding channels is spaced apart by a same or different first distance from another of the plurality of inclined in-guiding channels.

14. The multi-layer structure of any one of claims 2 to 13, further comprising at least one inclined out-guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide, wherein the at least one inclined out-guiding channel comprises a plurality of inclined out-guiding channels.

15. The multi-layer structure of claim 14, wherein each of the plurality of inclined out-guiding channels is inclined at a same or different second predetermined non-zero angle from another of the plurality of inclined out-guiding channels.

16. The multi-layer structure of claim 14 or 15, wherein each of the plurality of inclined out-guiding channels is spaced apart by a same or different second distance from another of the plurality of inclined out-guiding channels.

17. The multi-layer structure of claim 16,wherein the first distance comprises a value substantially the same or different from the second distance.

18. The multi-layer structure of any one of claims 13 to 17, wherein the first distance comprises a value between 10 um to 10 mm.

19. The multi-layer structure of any one of claims 16 to 18, wherein the second distance comprises a value between 10 um to 10 mm.

20. The multi-layer structure of any one of claims 2 to 19, wherein the first predetermined angle comprises a value substantially the same as the second predetermined angle.

21. The multi-layer structure of any one of claims 1 to 20, wherein the first predetermined non-zero angle comprises a value between 1° and 179°.

22. The multi-layer structure of any one of claims 2 to 21, wherein the second predetermined non-zero angle comprises a value between 1° and 179°.

23. The multi-layer structure of any one of claims 1 to 22, wherein the plurality of inclined in-guiding channels are substantially non-wavelength selective.

24. The multi-layer structure of claim 23, wherein the plurality of inclined in-guiding channels are substantially non-wavelength selective in a wavelength range from 400 nm to 1700 nm.

25. The multi-layer structure of any one of claims 1 to 24, wherein the plurality of inclined in-guiding channels comprise one or more materials selected from a group of materials consisting of polymer materials, metals, metal oxides, electro-opto organic materials and thermal-opto organic materials.

26. The multi-layer structure of any one of claims 2 to 25, wherein the plurality of inclined in-guiding channels are the same or different from the at least one inclined out- guiding channel.

27. The multi-layer structure of any one of claims 2 to 26, wherein the waveguide comprises a same or different material as the plurality of inclined in-guiding channels and the at least one inclined out-guiding channel.

28. The multi-layer structure of claim 9, further comprising a waveguide; a plurality of inclined in-guiding channels optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, and an in-capping portion disposed above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in-guiding channels of the plurality of inclined in-guiding channels, and wherein the in-capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide; at least one inclined out-guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; an out-capping portion disposed above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface; and at least one first active optical element disposed above the plurality of inclined in-guiding channels, wherein the waveguide, the plurality of inclined in-guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out- capping portion, the at least one first active optical element and the at least one second active optical element are integrated.

29. The multi-layer structure of claim 9, further comprising a waveguide; a plurality of inclined in-guiding channels optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, and an in-capping portion disposed above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in-guiding channels of the plurality of inclined in-guiding channels, and wherein the in-capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide; at least one inclined out-guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; an out-capping portion disposed above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface; and at least one first active optical element disposed above the plurality of inclined in-guiding channels, wherein the waveguide, the plurality of inclined in-guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out- capping portion, the at least one first active optical element and the at least one second active optical element are monolithically integrated.

30. The multi-layer structure of claim 9, further comprising a waveguide; a plurality of inclined in-guiding channels optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, and an in-capping portion disposed above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in-guiding channels of the plurality of inclined in-guiding channels, and wherein the in-capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide; at least one inclined out-guiding channel optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; an out-capping portion disposed above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface; and at least one first active optical element disposed above the plurality of inclined in-guiding channels, wherein the waveguide, the plurality of inclined in-guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out- capping portion, the at least one first active optical element and the at least one second active optical element comprises organic material.

31. The multi-layer structure of claim 9, further comprising at least one first active optical element disposed above the plurality of inclined in-guiding channels, wherein the at least one first active optical element and the at least one second active optical element comprises inorganic material.

32. The multi-layer structure of any one of claims 1 to 31, wherein the waveguide is disposed on a device substrate.

33. A method of forming a multi-layer structure comprising: forming a waveguide; forming a plurality of inclined in-guiding channels on the waveguide such that the plurality of inclined in-guiding channels are optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide; and forming an in-capping portion above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in- guiding channels of the plurality of inclined in-guiding channels, and wherein the in- capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide.

34. The method of claim 33, further comprising forming at least one inclined out- guiding channel on the waveguide such that the at least one inclined out-guiding channel is optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide.

35. The method of claim 34, wherein forming the at least one inclined out-guiding channel on the waveguide comprises forming the at least one inclined out-guiding channel such that the at least one inclined out-guiding channel is configured to direct the light out of the waveguide such that the light exiting the waveguide travels within the at least one inclined out-guiding channel.

36. The method of claim 35, further comprising forming at least one inclined out- guiding channel on the waveguide such that the at least one inclined out-guiding channel is optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; and forming an out-capping portion above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface.

37. The method of claim 36, wherein forming the in-capping portion is the same as forming the out-capping portion.

38. The method of any one of claims 33 to 37, further comprising forming at least one first active optical element above the plurality of inclined in-guiding channels.

39. The method of claim 38, wherein the forming the at least one first active optical element above the plurality of inclined in-guiding channels comprises forming the at least one first active optical element above the in-capping portion.

40. The method of claim 38 or 39, wherein the at least one first active optical element comprises at least one light source configured to provide the light.

41. The method of any one of claims 34 to 40, further comprising forming at least one inclined out-guiding channel on the waveguide such that the at least one inclined out- guiding channel is optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; and forming at least one second active optical element above the at least one inclined out-guiding channel.

42. The method of claim 41, further comprising forming an out-capping portion above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface, and wherein the forming the at least one second active optical element above the at least one inclined out-guiding channel comprises forming the at least one second active optical element above the out-capping portion.

43. The method of claim 41 or 42, wherein the at least one second active optical element comprises at least one photo detector.

44. The method of any one of claims 33 to 43, wherein forming the plurality of inclined in-guiding channels further comprises forming each of the plurality of inclined in-guiding channels inclined at the same or different first predetermined non-zero angle from another of the plurality of inclined in-guiding channels.

45. The method of any one of claims 33 to 44, wherein forming the plurality of inclined in-guiding channels further comprises forming each of the plurality of inclined in-guiding channels spaced apart by a same or different first distance from another of the plurality of inclined in-guiding channels.

46. The method of any one of claims 34 to 45, further comprising forming at least one inclined out-guiding channel on the waveguide such that the at least one inclined out- guiding channel is optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide, wherein forming the at least one inclined out-guiding channel on the waveguide comprises forming the at least one inclined out-guiding channel such that the at least one inclined out-guiding channel comprises a plurality of inclined out-guiding channels.

47. The method of claim 46, wherein forming the plurality of inclined out-guiding channels further comprises forming each of the plurality of inclined out-guiding channels inclined at the same or different second predetermined non-zero angle from another of the plurality of inclined out-guiding channels.

48. The method of claim 46 or 47, wherein forming the plurality of inclined out- guiding channels further comprises forming each of the plurality of inclined out-guiding channels spaced apart by a same or different second distance from another of the plurality of inclined out-guiding channels.

49. The method of claim 48, wherein the first distance comprises a value substantially the same or different from the second distance.

50. The method of any one of claims 45 to 49, wherein the first distance comprises a value between 10 um to 10 mm.

51. The method of any one of claims 48 to 50, wherein the second distance comprises a value between 10 um to 10 mm.

52. The method of any one of claims 34 to 51, wherein the first predetermined angle comprises a value substantially the same as the second predetermined angle.

53. The method of any one of claims 33 to 52, wherein the first predetermined non- zero angle comprises a value between 1° and 179°.

54. The method of any one of claims 34 to 53, wherein the second predetermined non-zero angle comprises a value between 1° and 179°.

55. The method of any one of claims 33 to 54, wherein the plurality of inclined in- guiding channels are substantially non-wavelength selective.

56. The method of claim 55, wherein the plurality of inclined in-guiding channels are substantially non-wavelength selective in a wavelength range from 400 nm to 1700 nm.

57. The method of any one of claims 33 to 56, wherein the plurality of inclined in- guiding channels comprise one or more materials selected from a group of materials consisting of polymer materials, metals, metal oxides, electro-opto organic materials and thermal-opto organic materials.

58. The method of any one of claims 34 to 57, wherein forming the plurality of inclined in-guiding channels is the same as forming the at least one inclined out-guiding channel.

59. The method of any one of claims 34 to 58, wherein the waveguide comprises a same or different material as the plurality of inclined in-guiding channels and the at least one inclined out-guiding channel.

60. The method of claim 41, further comprising forming a waveguide; forming a plurality of inclined in-guiding channels on the waveguide such that the plurality of inclined in-guiding channels are optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, and forming an in-capping portion above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in-guiding channels of the plurality of inclined in-guiding channels, and wherein the in-capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide; forming at least one inclined out-guiding channel on the waveguide such that the at least one inclined out-guiding channel is optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; forming an out-capping portion above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface; and forming at least one first active optical element above the plurality of inclined in-guiding channels, wherein forming the waveguide, the plurality of inclined in- guiding channels, the at least one inclined out-guiding channel, the in-capping portion,

the out-capping portion, the at least one first active optical element and the at least one second active optical element comprises forming the waveguide, the plurality of inclined in-guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element such that the waveguide, the plurality of inclined in- guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element are integrated.

61. The method of claim 41, further comprising forming a waveguide; forming a plurality of inclined in-guiding channels on the waveguide such that the plurality of inclined in-guiding channels are optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, and forming an in-capping portion above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in-guiding channels of the plurality of inclined in-guiding channels, and wherein the in-capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide; forming at least one inclined out-guiding channel on the waveguide such that the at least one inclined out-guiding channel is optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; forming an out-capping portion above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface; and forming at least one first active optical element above the plurality of inclined in-guiding channels, wherein forming the waveguide, the plurality of inclined in- guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element comprises forming the waveguide, the plurality of inclined in-guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element such that the waveguide, the plurality of inclined in- guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out-capping portion, the at least one first active optical element and the at least one second active optical element are monolithically integrated.

62. The method of claim 41, further comprising forming a waveguide; forming a plurality of inclined in-guiding channels on the waveguide such that the plurality of inclined in-guiding channels are optically coupled to the waveguide and inclined at a first predetermined non-zero angle to a surface of the waveguide, and forming an in-capping portion above the plurality of inclined in-guiding channels, wherein the in-capping portion includes at least one planar surface and further comprises a concave surface or a convex surface at a gap region between two respective inclined in-guiding channels of the plurality of inclined in-guiding channels, and wherein the in-capping portion is configured to receive light and to guide the light to the plurality of inclined in-guiding channels, wherein the plurality of inclined in-guiding channels are configured to receive the light from the in-capping portion and to direct the light through the surface to the waveguide such that the light travels within the plurality of inclined in-guiding channels by means of reflection into the waveguide; forming at least one inclined out-guiding channel on the waveguide such that the at least one inclined out-guiding channel is optically coupled to the waveguide and inclined at a second predetermined non-zero angle to the surface of the waveguide; forming an out-capping portion above the at least one inclined out-guiding channel, wherein the out-capping portion includes at least one planar surface; and forming at least one first active optical element above the plurality of inclined in-guiding channels, wherein the waveguide, the plurality of inclined in-guiding channels, the at least one inclined out-guiding channel, the in-capping portion, the out- capping portion, the at least one first active optical element and the at least one second active optical element comprises organic material.

63. The method of claim 41, further comprising forming at least one first active optical element above the plurality of inclined in-guiding channels, wherein the at least one first active optical element and the at least one second active optical element comprises inorganic material.

64. The method of any one of claims 33 to 63, wherein forming the plurality of inclined in-guiding channels on the waveguide comprises depositing a light in-coupling layer above the surface of the waveguide.

65. The method of claim 64, wherein forming the plurality of inclined in-guiding channels on the waveguide further comprises directly applying an UV laser source over the light in-coupling layer.

66. The method of claim 65, wherein forming the plurality of inclined in-guiding channels on the waveguide further comprises positioning the UV laser source at a first laser predetermined non-zero angle relative to the light in-coupling layer.

67. The method of claim 64, wherein forming the plurality of inclined in-guiding channels on the waveguide further comprises exposing ultra-violet radiation at a first exposure predetermined non-zero angle relative to the light in-coupling layer.

68. The method of claim 66, wherein the first laser predetermined non-zero angle is the same or different from the first predetermined non-zero angle.

69. The method of claim 67, wherein the first exposure predetermined non-zero angle is the same or different from the first predetermined non-zero angle.

70. The method of claim 34, wherein forming the at least one inclined out-guiding channel on the waveguide comprises depositing a light out-coupling layer above the surface of the waveguide.

71. The method of claim 70, wherein forming the at least one inclined out-guiding channel on the waveguide further comprises directly positioning a further UV laser source over the light out-coupling layer.

72. The method of claim 71, wherein forming the at least one inclined out-guiding channel on the waveguide further comprises positioning the further UV laser source at a second laser predetermined non-zero angle relative to the light out-coupling layer.

73. The method of claim 70, wherein forming the at least one inclined out-guiding channel on the waveguide further comprises exposing ultra-violet radiation at a second exposure predetermined non-zero angle relative to the light out-coupling layer.

74. The method of claim 72, wherein the second laser predetermined non-zero angle is the same or different from the second predetermined non-zero angle.

75. The method of claim 73, wherein the second exposure predetermined non-zero angle is the same or different from the second predetermined non-zero angle.