KR102600463B1 - Optical Device Module and Optical Communication Network System Used the Same - Google Patents

Abstract

The present invention relates to a substrate; an optical waveguide on the substrate; a light source providing light into the optical waveguide; and a prism between the light source and the optical waveguide. The light source includes a lens.

Description

Optical module and optical communication network system equipped with same {Optical Device Module and Optical Communication Network System Used the Same}

The present invention relates to an optical module including a lens and an optical communication network system equipped therewith.

As electronic devices tend to become smaller and faster, research is continuing to increase the integration of the components that make up the electronic devices. In order to miniaturize and increase the speed of electronic devices, fast signal transmission between the components is required along with miniaturization of the components.

As a means of fast signal transmission between components, the application of optical communication technology between electronic devices is being attempted. When optical communication technology is applied to electronic devices, not only can signal transmission be performed at a faster speed, but the disadvantages of existing signal transmission methods, such as high resistance, high heat generation, and parasitic capacitance phenomena, can be alleviated.

Recently, research has been actively conducted to introduce technologically mature optical fiber communication technology into computers. Typically, silicon photonics technology uses silicon materials as optical waveguides to transmit optical signals. In addition, research to directly utilize existing optical fiber optical communication technology by inserting an optical fiber into the PCB board of a computer is also actively being conducted.

The purpose of the present invention is to provide an optical module capable of emitting parallel light from a light source and an optical communication network system equipped therewith.

The present invention relates to a substrate; an optical waveguide on the substrate; a light source providing light into the optical waveguide; and a prism between the light source and the optical waveguide, wherein the light source includes a lens.

The lens may include a flat base portion and a hemispherical protrusion protruding from the base toward the prism.

The light source may include an adhesive layer covering the lens, and a light transmitting portion on the adhesive layer.

The light source further includes a light generator that emits the light toward the lens, and the lens may satisfy [Equation 1] below.

[Equation 1]

F·tan ^-1 (1/2·θ1) < R

The radius of the lens may be 1㎛ to 100㎛.

The refractive index of the lens may be 1.65 to 2.5, and the refractive index of the adhesive layer may be 1.3 to 1.55.

The lens may include at least one of SiC, GaN, Si ₃ N ₄ , TiN, LiNbO ₃ , TiO ₂ , ZnSe, and polyimide.

It may further include an anti-reflection film covering the lower surface and inclined surface of the prism.

The light passing through the lens may be parallel light.

The present invention relates to a substrate; an optical waveguide on the substrate; a filter on the optical waveguide; a prism on the filter; and a light source on an inclined surface of the prism.

The filter may be a wavelength division multiplexing filter.

The filter may include an upper mirror, a lower mirror, and a spacer between the upper and lower mirrors.

The length of the path along which the light emitted from the light source passes through the upper mirror, the spacer, and the lower mirror may be the same.

The upper mirror and the lower mirror may have a symmetrical structure with respect to the spacer.

It further includes a buffer layer between the filter and the optical waveguide, wherein the upper mirror includes a first filter film in contact with the prism and a second filter film in contact with the spacer, and the lower mirror includes a third filter film in contact with the spacer. and a fourth filter film in contact with the buffer layer, wherein the first filter film and the fourth filter film may have the same thickness and refractive index, and the second filter film and the third filter film may have the same thickness and refractive index.

The refractive index of the spacer may be the same as the refractive index of the first filter film.

The present invention relates to a substrate having a sub-control region, a connection region, and a sub-unit cell region; a first light source and a first detector on the sub-control area; a second light source and a second detector on the sub-unit cell area; a first optical waveguide connecting the first light source and the second detector and a second optical waveguide connecting the second light source and the first detector; and a first prism between the first light source and the first optical waveguide, and a second prism between the second light source and the second optical waveguide.

It may further include a first filter between the first prism and the first optical waveguide, and a second filter between the second prism and the second optical waveguide.

It may further include anti-reflection films covering lower surfaces and inclined surfaces of each of the first and second prisms.

Each of the first light source and the second light source may include a lens.

In the optical module and optical communication network system equipped with the same according to the present invention, the light source includes a lens, so that parallel light can be emitted from the light source.

1 is a diagram schematically illustrating an optical communication network system according to an embodiment of the present invention.
Figure 2 is a diagram for explaining sub-control parts and sub-unit cell parts in more detail.
Figure 3 is a cross-sectional view showing an optical module according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view illustrating conditions for the light source of FIG. 3 to emit parallel light.
Figure 5 is a cross-sectional view of an optical module according to an embodiment of the present invention.
Figure 6A is a cross-sectional view of an optical module according to an embodiment of the present invention.
Figure 6b is an enlarged view of area A of Figure 6a.
Figure 7a is a graph showing the reflectivity of a mirror.
Figure 7b is a graph showing the transmittance of the filter using the mirror of Figure 7a.
Figure 8 is a diagram for explaining the function of an optical module including a filter.
Figure 9 is a cross-sectional view showing an optical module according to an embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to provide common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, 'comprises' and/or 'comprising' refers to the presence of one or more other components, steps, operations and/or devices. or does not rule out addition. Hereinafter, embodiments of the present invention will be described in detail.

1 is a diagram schematically illustrating an optical communication network system according to an embodiment of the present invention.

Referring to Figure 1, the optical communication network system according to an embodiment of the present invention includes main control parts 20, sub control parts 30, sub unit cell parts 40, and optical waveguides 50. can do. The optical waveguides 50 may connect the main control portions 20, sub-control portions 30, and sub-unit cell portions 40 to each other. The main control parts 20 may output a control signal for controlling the sub-control parts 30 and the sub-unit cell parts 40 and receive a response signal. The sub-control parts 30 communicate with the main control parts 20 and can control the sub-unit cell parts 40. One sub-control portion 30 and 16 sub-unit cell portions 40 may constitute unit cell portions 60, respectively. When the unit cell portions 60 are composed of 16, the unit cell portions 60 may include 16 ² sub-unit cell portions 40. Additionally, one main control part 20 and 16 unit cell parts 60 may constitute upper unit cells 70. Although not shown, the 16 upper unit cell portions 70 may include 16 ³ sub unit cell portions 40. The upper unit cell 70 and the super main control parts (not shown) may form a high-dimensional unit cell. Accordingly, as the dimension of the unit cell portions 60 increases, the optical communication network system of the present invention may include sub-unit cell portions 40 designed to a higher order number of 16.

The sub-control parts 30 transmit the optical signal of the sub-unit cell parts 40 to other sub-unit cell parts 40, other unit cells 60, or higher unit cells within the unit cell part 60 of the same group. You can decide whether to output it at (70). The main control parts 20, sub-control parts 30, and sub-unit cell parts 40 may each perform photoelectric conversion between optical signals and electric signals.

Figure 2 is a diagram for explaining sub-control parts and sub-unit cell parts in more detail.

Referring to FIGS. 1 and 2 , the sub-control parts 30 may include light emitting arrays (LD array) and light receiving arrays (PD array). The light emitting array (LD array) of the sub-control portions 30 may include first light sources 72, and the light receiving array (PD array) may include first detectors 74. The sub-unit cell portions 40 may include a portion of a light emitting array (LD array) and a portion of a light receiving array (PD array). Sub-unit cell portions 40 may include a second light source 78 and may include a second detector 76. The first light source 72 and the second light source 78 may include a vertical cavity surface emitting laser (VCSEL) or a laser diode. The first detector 74 and the second detector 76 may include photo diodes. The first light source 72 and the second detector 76 may be connected by a first optical waveguide 52. The first light source 72, first optical waveguide 52, and second detector 76 may be a first communication line. Additionally, the second optical waveguide 54 may connect the first detector 74 and the second light source 78. Likewise, the first detector 74, second optical waveguide 54, and second light source 78 can be a second communication line. The first optical waveguide 52 and the second optical waveguide 54 may connect the sub-control portions 30 and the sub-unit cell portions 40 without intersecting each other.

The first light source 72, first detector 74, second light source 78, and second detector 76 are optical elements. Optical elements may be combined with optical waveguides to form an optical module. The optical waveguide 50 can connect optical modules. The sub-unit cell portions 40 may have a plurality of optical modules for transmitting and receiving optical signals.

Hereinafter, an optical module capable of maximizing optical coupling efficiency will be described using embodiments.

Figure 3 is a cross-sectional view showing an optical module according to an embodiment of the present invention.

Referring to FIG. 3, the optical module includes a substrate 100, a lower clad layer 110, an optical waveguide 120, an upper clad layer 130, a buffer layer 140, a prism 150, and a light source 200. can do.

Substrate 100 may include crystalline silicon. Crystalline silicon can have a refractive index of about 3.45. Although not shown, the substrate 100 may have a sub-control area, a connection area, and a sub-unit cell area. The sub-control area may correspond to the sub-control cell portions 30 of FIGS. 1 and 2. The sub-unit cell area may correspond to the sub-unit cell portions 40 of FIGS. 1 and 2. The connection area may be an area between the sub-control area and the sub-unit cell area.

A lower clad layer 110 may be provided on the substrate 100. The lower clad layer 110 may include silicon oxide. Silicon oxide may have a refractive index of about 1.45.

The optical waveguide 120 may be provided on the lower clad layer 110. The lower clad layer 110 may have a lower refractive index than the optical waveguide 120. The optical waveguide 120 may have a lower refractive index than the substrate 100. The optical waveguide 120 may include silicon nitride or silicon oxynitride. Silicon nitride may have a refractive index of about 2.0. Silicon oxy nitride may have a refractive index of about 1.7. The optical waveguide 120 may correspond to the optical waveguide 50 of FIGS. 1 and 2 .

The upper surface of the optical waveguide 120 may be divided into a first part and a second part. The upper clad layer 130 may cover the first portion of the upper surface of the optical waveguide 120. The upper clad layer 130 may expose a second portion of the upper surface of the optical waveguide 120. The refractive index of the upper clad layer 130 may be lower than the refractive index of the optical waveguide 120. The upper clad layer 130 may include silicon oxide.

The buffer layer 140 may cover the second portion of the upper surface of the optical waveguide 120. In other words, the buffer layer 140 may cover the upper surface of the optical waveguide 120 exposed by the upper clad layer 130. The buffer layer 140 may have a higher refractive index than the optical waveguide 120. The buffer layer 140 may include index matching oil or adhesive having a refractive index of about 1.7 to 2.1.

The prism 150 may be disposed on the buffer layer 140. The lower surface 151 of the prism 150 may be in contact with the buffer layer 140. The buffer layer 140 can prevent air from entering between the prism 150 and the optical waveguide 120. When air flows between the prism 150 and the optical waveguide 120, the light transmission efficiency between the prism 150 and the optical waveguide 120 may decrease. The prism 150 may have a higher refractive index than the buffer layer 140. The prism 150 may have a wedge shape with an inclined surface 152. The inclination angle of the prism 150 may be defined as the first angle θ1. Prism 150 may include crystalline silicon or gallium phosphide (GaP). Gallium phosphide may have a refractive index of about 3.05.

The light source 200 may contact the inclined surface 152 of the prism 150. The light source 200 of this embodiment may correspond to the first light source 72 or the second light source 78 of FIGS. 1 and 2. Instead of the light source 200, a detector corresponding to the first detector 74 or the second detector 76 of FIGS. 1 and 2 may be provided.

The light source 200 may provide laser light (L) to the optical waveguide 120. The light source 200 may include a light generating unit 210, a lens 220, an adhesive layer 230, and a light transmitting unit 240.

The light generator 210 may generate and emit laser light (L). The light generator 210 may be a vertical cavity surface emitting laser (VCSEL) or a laser diode. The laser light L emitted from the light generator 210 may have a second angle θ2 as a radiation angle. For example, the second angle θ2 may be 20 degrees to 40 degrees. The light generator 210 may include an opening 211, and laser light L may be emitted from the opening 211.

A lens 220 may be provided on the light generating unit 210. The lens 220 may include a base portion 221 and a protrusion 222. The base portion 221 may have the shape of a flat plate. The protrusion 222 may have a hemispherical shape. The base portion 221 may be provided on the light generating portion 210, and the protrusion 222 may protrude from the base portion 221 toward the prism 150. Lens 220 may have a refractive index of 1.65 to 2.5. The lens 220 may include at least one of SiC, GaN, Si ₃ N ₄ , TiN, LiNbO ₃ , TiO ₂ , ZnSe, and polyimide.

An adhesive layer 230 may be provided on the lens 220. The adhesive layer 230 may cover the lens 220. In other words, the adhesive layer 230 may cover the top surface 221a of the base portion 221 of the lens 220 and the top surface 222a of the protrusion 222 of the lens 220. The adhesive layer 230 may have a refractive index of 1.3 to 1.55. The adhesive layer 230 may include an optical adhesive.

A light transmitting portion 240 may be provided on the adhesive layer 230. The light transmitting portion 240 may include glass or quartz. Although the light transmitting portion 240 is shown as being in contact with the protruding portion 222 of the lens 220, the light transmitting portion 240 may not be limited thereto. In other words, the light transmitting portion 240 may be spaced apart from the protrusion 222 of the lens 220 by the adhesive layer 230.

When explaining the operation of the optical module according to an embodiment of the present invention, laser light (L) generated in the light generating unit 210 of the light source 200 may pass through the lens 220 and the adhesive layer 230. As it passes through the lens 220 and the adhesive layer 230, the radiation angle of the laser light L may decrease. Accordingly, the laser light L passing through the light transmitting part 240 may be parallel light. In other words, the radiation angle of the laser light L passing through the light transmitting part 240 may be 0 degrees.

The laser light (L) passing through the light transmitting portion 240 may be incident perpendicularly to the inclined surface 152 of the prism 150 and pass through the prism 150. The laser light L passing through the prism 150 may form a third angle θ3 with the lower surface 151 of the prism 150. The third angle θ3 may correspond to the inclination angle of the prism 150. In other words, the sum of the first angle θ1 and the third angle θ3 may be 90 degrees.

The laser light L that has passed through the prism 150 may pass through the buffer layer 140 and be incident into the optical waveguide 120. The laser light L incident on the optical waveguide 120 may be reflected from the lower clad layer 110 and the upper clad layer 130 and may proceed along the optical waveguide 120.

If the light passing through the light transmitting part 240 of the light source 200 is not parallel light, the laser light L may not pass through the prism 150 and the buffer layer 140 and be focused on the optical waveguide 120. For example, if the radiation angle of the laser light (L) passing through the light transmitting part 240 is 2 degrees or more, the laser light (L) may not be focused on the optical waveguide 120. In the present invention, the laser light (L) emitted from the light source 200 is converted into parallel light, so that the laser light (L) can be focused on the optical waveguide 120.

Describing the manufacturing method of the optical module according to an embodiment of the present invention, an adhesive layer 230 may be formed on the lens 220, and the light transmitting portion 240 may be attached to the adhesive layer 230. Next, the light source 200 can be manufactured by attaching the lens 220 to the light generating unit 210. Next, by attaching the light source 200 to the prism 150 and attaching the prism 150 to the buffer layer 140, manufacturing of the optical module can be completed.

FIG. 4 is a diagram for explaining conditions for the light source of FIG. 3 to emit parallel light.

Referring to FIG. 4, the laser light L emitted from the light generating unit 210 of the light source 200 may have a second angle θ2 as a radiation angle. The second angle θ2 may be 20 to 40 degrees. The laser light L passing through the light transmitting part 240 of the light source 200 may be parallel light. In other words, the radiation angle of the laser light L passing through the light transmitting part 240 of the light source 200 may be 0 degrees.

In order for the laser light (L) passing through the light transmitting portion 240 to become parallel light, the conditions according to [Equation 1] below must be satisfied.

In the above [Equation 1], F is the focal length of the protrusion 222 of the lens 200, R is the radius of the protrusion 222 of the lens 200, and θ2 is the light emitted from the light generator 210. This is the radiation angle (second angle) of the laser light (L). In Equation 1, the first distance D1 may be defined by the focal length F and the second angle θ2.

The focal length (F) of the protrusion 222 of the lens 200 can be derived according to [Equation 2] below.

In the above [Equation 2], n1 is the refractive index of the lens 220, and n2 is the refractive index of the adhesive layer 230.

If the condition of [Equation 1] is satisfied and the first distance D1 is smaller than the radius (R) of the protrusion 222 of the lens 220, the laser light (L) passing through the light transmitting portion 240 This can be parallel light. If the condition of [Equation 1] is not satisfied and the first distance D1 is greater than the radius (R) of the protrusion 222 of the lens 220, the laser light (L) passing through the light transmitting portion 240 This cannot be parallel light.

Referring to [Equation 1] and [Equation 2] above, the radius (R) of the protrusion 222 of the lens 220, the refractive index (n1) of the lens 220, and the refractive index (n2) of the adhesive layer 230 By appropriately setting, the conditions according to [Equation 1] above can be satisfied. For example, when the second angle θ2 is 30 degrees, the refractive index n2 of the adhesive layer 230 is 1.46, and the radius R of the protrusion 222 of the lens 220 is 15㎛, the lens ( If the refractive index (n1) of 220) is set to 1.72 or more, the laser light (L) passing through the light transmitting part 240 may become parallel light. When the lens 220 includes polyimide, the refractive index (n1) may be 1.72.

The radius (R) of the protrusion 222 of the lens 220 may be 1 μm to 100 μm, the refractive index (n1) of the lens 220 may be 1.65 to 2.5, and the refractive index (n2) of the adhesive layer 230 may be 1.3 to 1.55.

Figure 5 is a cross-sectional view of an optical module according to an embodiment of the present invention. The optical module according to this embodiment is similar to the optical module according to FIG. 3 except as described below.

Referring to FIG. 5 , the optical module may further include an anti-reflection film 160. The anti-reflection film 160 may include a first part 161 and a second part 162.

The first portion 161 of the anti-reflection film 160 may be provided on the lower surface 151 of the prism 150. The second portion 162 of the anti-reflection film 160 may be provided on the inclined surface 152 of the prism 150. The thickness of the first part 161 and the thickness of the second part 162 may be substantially the same. In other words, the anti-reflection film 160 may conformally cover the lower surface 151 and the inclined surface 152 of the prism 150.

The anti-reflective film 160 may include first reflective films and second reflective films that are alternately stacked. The thickness of the first reflective films and the thickness of the second reflective films may be different from each other. The material included in the first reflective films and the material included in the second reflective films may be different from each other. The refractive index of the first reflective films and the refractive index of the second reflective films may be different from each other.

The prism 150 and the buffer layer 140 may be spaced apart from each other with the first portion 161 of the anti-reflection film 160 interposed therebetween. The prism 150 and the light transmitting portion 240 of the light source 200 may be spaced apart from each other with the second portion 162 of the anti-reflection film 160 interposed therebetween.

Figure 6A is a cross-sectional view of an optical module according to an embodiment of the present invention. Figure 6b is an enlarged view of area A of Figure 6a. The optical module according to this embodiment is similar to the optical module according to FIG. 3 except as described below.

Referring to FIGS. 6A and 6B, the optical module may further include a filter 170. The filter 170 may be a Wavelength Division Multiflexing (WDM) Filter. The filter 170 may be provided on the lower surface 151 of the prism 150. The prism 150 and the buffer layer 140 may be spaced apart from each other with the filter 170 interposed therebetween.

The filter 170 may include an upper mirror 171, a spacer 172, and a lower mirror 173. The spacer 172 may be disposed between the upper mirror 171 and the lower mirror 173. The upper mirror 171 may be in contact with the lower surface 151 of the prism 150. The lower mirror 173 may contact the upper surface of the buffer layer 140.

The upper mirror 171 may include a pair of first filter membranes 171a and second filter membranes 171b. The first and second filter membranes 171a and 171b may include different materials. For example, the first filter film 171a may include TiO ₂ and the second filter film 171b may include Ta ₂ O ₅ . The refractive indices of the first and second filter films 171a and 171b may be different from each other. The thickness of the first and second filter films 171a and 171b may be different from each other. The first filter film 171a may contact the prism 150, and the second filter film 171b may contact the spacer 172.

The upper mirror 171 is shown as including a pair of first filter films 171a and second filter films 171b, but may not be limited thereto. The upper mirror 171 may include a plurality of pairs of first filter films 171a and second filter films 171b. In this case, the first filter films 171a and the second filter films 171b may be provided alternately.

The spacer 172 may include the same material as the first filter membrane 171a. As shown, when the upper mirror 171 includes a pair of first filter films 171a and second filter films 171b, the thickness of the spacer 172 is equal to the thickness of the first filter film 171a. It may be twice that of Unlike shown, for example, when the upper mirror 171 includes two pairs of first filter films 171a and second filter films 171b, the thickness of the spacer 172 is the first filter film (171a). It may be 4 times that of 171a).

The lower mirror 173 may include a third filter film 173a and a fourth filter film 173b. The third and fourth filter membranes 173a and 173b may contain different materials. The third filter film 173a may include the same material as the second filter film 171b of the upper mirror 171. The fourth filter film 173b may include the same material as the first filter film 171a of the upper mirror 171. The third and fourth filter films 173a and 173b may have different thicknesses. The thickness of the third filter film 173a may be the same as the thickness of the second filter film 171b of the upper mirror 171. The thickness of the fourth filter film 173b may be the same as the thickness of the first filter film 171a of the upper mirror 171. The third filter film 173a may contact the spacer 172, and the fourth filter film 173b may contact the buffer layer 140.

The lower mirror 173 is shown as including a pair of third filter films 173a and fourth filter films 173b, but may not be limited thereto. The lower mirror 173 may include a plurality of pairs of third filter films 173a and fourth filter films 173b. In this case, the third filter films 173a and fourth filter films 173b may be provided alternately.

The upper mirror 171 and the lower mirror 173 may have a symmetrical structure with respect to the spacer 172.

The filter 170 can pass laser light of a specific wavelength. For example, with reference to FIG. 6B, the filter 170 may pass laser light of the first wavelength (λ1) and may reflect laser light of a different wavelength than the first wavelength (λ1). When the laser light of the first wavelength (λ1) passes through the prism 150 and enters the filter 170, it may pass through the upper mirror 171, the spacer 172, and the lower mirror 173. While passing through the upper mirror 171, spacer 172, and lower mirror 173, the laser light may be refracted.

In the first filter film 171a of the upper mirror 171, the length of the path through which the laser light passes may be 1/4 times the first wavelength λ1. In the second filter film 171b of the upper mirror 171, the length of the path through which the laser light passes may be 1/4 times the first wavelength λ1. The refractive index and thickness of the first filter film 171a and the second filter film 171b can be set so that the length of the path through which the laser light passes is 1/4 times the first wavelength (λ1). In conclusion, the length of the path through which the laser light passes in the upper mirror 171 may be 1/2 times the first wavelength (λ1).

Unlike what is shown, for example, when the upper mirror 171 includes two pairs of first filter films 171a and second filter films 171b, the path along which the laser light passes through the upper mirror 171 The length may be equal to the first wavelength (λ1).

In the spacer 172, the length of the path through which the laser light passes may be 1/2 times the first wavelength (λ1). In other words, the length of the path through which the laser light passes may be the same in the spacer 172 and the upper mirror 171. The refractive index and thickness of the spacer 172 can be set so that the length of the path through which the laser light passes is 1/2 times the first wavelength (λ1).

In the third filter film 173a of the lower mirror 173, the length of the path through which the laser light passes may be 1/4 times the first wavelength λ1. In the fourth filter film 173b of the lower mirror 173, the length of the path through which the laser light passes may be 1/4 times the first wavelength λ1. The refractive index and thickness of the third filter film 173a and the fourth filter film 173b can be set so that the length of the path through which the laser light passes is 1/4 times the first wavelength (λ1). In conclusion, the length of the path through which the laser light passes in the lower mirror 173 may be 1/2 times the first wavelength (λ1).

Unlike what is shown, for example, when the lower mirror 173 includes two pairs of third filter films 173a and fourth filter films 173b, the length of the path through which the laser light passes is the first wavelength ( It may be the same as λ1).

The filter 170 having the structure described above can pass laser light of the first wavelength (λ1) and reflect laser light of a different wavelength than the first wavelength (λ1).

Figure 7a is a graph showing the reflectivity of a mirror. Figure 7b is a graph showing the transmittance of the filter using the mirror of Figure 7a.

Referring to FIG. 7A, the reflectivity when laser light is incident on a mirror (upper mirror or lower mirror) including four pairs of first and second filter films can be confirmed. In the mirror, the refractive index and thickness of the first and second filter films are set so that the path length of the laser light passing through the first and second filter films is 1/4 times 850 nm. In Figure 7a, it can be seen that the laser light has a relatively high reflectivity around 850 nm.

Referring to FIG. 7B, the transmittance when laser light is incident on a filter using the mirrors of FIG. 7A as the upper and lower mirrors can be confirmed. The filter is set so that the path length of the laser light in the upper mirror is twice 850 nm, the path length in the spacer is twice 850 nm, and the path length in the lower mirror is twice 850 nm. It can be seen that laser light has relatively high transmittance at 850 nm.

Figure 8 is a diagram for explaining the function of an optical module including a filter.

Referring to FIG. 8, the optical module according to this embodiment may be provided with first to fourth prisms 150a, 150b, 150c, and 150d on the optical waveguide 120. The first to fourth prisms 150a, 150b, 150c, and 150d may be connected to the optical waveguide 120 through the buffer layers 140. A first filter 170a may be provided under the first prism 150a, a second filter 170b may be provided under the second prism 150b, and a third filter may be provided under the third prism 150c. A filter 170c may be provided, and a fourth filter 170d may be provided below the fourth prism 150d. The first and fourth filters 170a and 170d may pass laser light of the second wavelength λ2 and may reflect laser light of a different wavelength from the second wavelength λ2. The second and third filters 170b and 170c may pass laser light of the third wavelength λ3 and may reflect laser light of a different wavelength than the third wavelength λ3.

A first light source 200a may be provided on the first prism 150a, a second light source 200b may be provided on the second prism 150b, and a first light source 200b may be provided on the third prism 150c. A detector 300a may be provided, and a second detector 300b may be provided on the fourth prism 150d.

Laser light of a second wavelength (λ2) may be emitted from the first light source 200a. The first filter 170a may pass laser light of the second wavelength (λ2). Laser light of the second wavelength λ2 may pass through the first filter 170a, enter the optical waveguide 120, and proceed within the optical waveguide 120.

Proceeding within the optical waveguide 120, laser light of the second wavelength λ2 may pass under the second and third filters 170b and 170c. Since the laser light of the second wavelength (λ2) is reflected by the second and third filters 170b and 170c, the laser light of the second wavelength (λ2) passes through the second filter (170b) and enters the second prism (150b). ) may not be emitted above, and may not be emitted above the third prism (150c) after passing through the third filter (170c). The laser light of the second wavelength (λ2) that passes under the second and third filters 170b and 170c along the optical waveguide 120 passes through the fourth filter 170d and is emitted onto the fourth prism 150d. You can.

The laser light of the third wavelength (λ3) emitted from the second light source 200b sequentially passes through the second filter 170b, the optical waveguide 120, and the third filter 170c onto the third prism 150c. may be released.

As above, first to fourth filters 170a, 170b, 170c, and 170d are provided below the first and second light sources 200a and 200b and the first and second detectors 300a and 300b, The path of laser light may vary depending on the wavelength.

Figure 9 is a cross-sectional view showing an optical module according to an embodiment of the present invention. The optical module according to this embodiment is similar to the optical module according to FIG. 3 except as described below.

Referring to FIG. 9 , the optical module may further include a connection electrode 180, a wire 190, and a case 400. The connection electrode 180 may be provided on the upper clad layer 130. The connection electrode 180 may contact the buffer layer 140 on the upper clad layer 130. The top surface of the connection electrode 180 and the top surface of the buffer layer 140 may be coplanar. Although not shown, the connection electrode 180 may be electrically connected to an external electrical circuit.

The light generating unit 210 of the light source 200 may further include an internal electrode 212. The internal electrode 212 and the connection electrode 180 may be electrically connected by a wire 190.

Case 400 may include empty space therein. A light source 200, a prism 150, and a wire 190 may be accommodated in the empty space. In other words, the light source 200, prism 150, and wire 190 may be sealed by the case 400. The light source 200, prism 150, and wire 190 may be protected from external forces by the case 400. The first portion of the case 400 may be in contact with the upper surface of the buffer layer 140. The second portion of the case 400 may be in contact with the upper surface of the connection electrode 180. The connection electrode 180 is provided between the case 400 and the upper clad layer 130 to connect the empty space inside the case 400 and the external space.

Above, embodiments of the present invention have been described with reference to the attached drawings, but those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical idea or essential features. You will understand that it exists. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

100: substrate
120: optical waveguide
140: buffer layer
200: light source

Claims (20)

Board;
an optical waveguide on the substrate;
a filter on the optical waveguide;
a light source providing light into the optical waveguide; and
comprising a prism between the light source and the optical waveguide,
The light source includes a lens,
The filter is disposed between the prism and the optical waveguide,
The light emitted from the light source passes through the filter and is provided within the optical waveguide,
The filter includes an upper mirror, a lower mirror, and a spacer between the upper mirror and the lower mirror,
Further comprising a buffer layer between the filter and the optical waveguide,
The upper mirror includes a first filter film in contact with the prism and a second filter film in contact with the spacer,
The lower mirror includes a third filter film in contact with the spacer and a fourth filter film in contact with the buffer layer,
The first filter membrane and the fourth filter membrane have the same thickness and refractive index,
The optical module wherein the second filter film and the third filter film have the same thickness and refractive index.
According to claim 1,
The lens is an optical module including a flat base portion and a hemispherical protrusion protruding from the base toward the prism.
According to claim 1,
The light source is an optical module including an adhesive layer covering the lens, and a light transmitting portion on the adhesive layer.
According to claim 1,
The light source further includes a light generator that emits the light toward the lens,
The lens is an optical module that satisfies [Equation 1] below.
[Equation 1]
F·tan ^-1 (1/2·θ1) < R
(In [Equation 1], F is the focal length of the lens, θ1 is the radiation angle of the light emitted from the light generating unit, and R is the radius of the lens).
According to claim 1,
The optical module has a radius of 1㎛ to 100㎛.
According to clause 3,
The refractive index of the lens is 1.65 to 2.5,
An optical module wherein the adhesive layer has a refractive index of 1.3 to 1.55.
According to claim 1,
The lens is an optical module including at least one of SiC, GaN, Si ₃ N ₄ , TiN, LiNbO ₃ , TiO ₂ , ZnSe, and Polyimide.
According to claim 1,
An optical module further comprising an anti-reflection film covering a lower surface and an inclined surface of the prism.
According to claim 1,
The optical module wherein the light passing through the lens is parallel light.
Board;
an optical waveguide on the substrate;
a filter on the optical waveguide;
a prism on the filter; and
Comprising a light source on the inclined surface of the prism,
The filter is disposed between the prism and the optical waveguide,
Light emitted from the light source passes through the filter and is provided into the optical waveguide,
The filter includes an upper mirror, a lower mirror, and a spacer between the upper mirror and the lower mirror,
Further comprising a buffer layer between the filter and the optical waveguide,
The upper mirror includes a first filter film in contact with the prism and a second filter film in contact with the spacer,
The lower mirror includes a third filter film in contact with the spacer and a fourth filter film in contact with the buffer layer,
The first filter membrane and the fourth filter membrane have the same thickness and refractive index,
The optical module wherein the second filter film and the third filter film have the same thickness and refractive index.
According to claim 10,
The filter is an optical module that is a wavelength division multiplexing filter.
delete According to claim 10,
The optical module wherein the length of the path through which the light emitted from the light source passes through the upper mirror, the spacer, and the lower mirror is the same.
According to claim 10,
An optical module wherein the upper mirror and the lower mirror have a symmetrical structure with respect to the spacer.
delete According to claim 10,
The optical module wherein the refractive index of the spacer is the same as the refractive index of the first filter film.
A substrate having a sub-control region, a connection region, and a sub-unit cell region;
a first light source and a first detector on the sub-control area;
a second light source and a second detector on the sub-unit cell area;
a first optical waveguide connecting the first light source and the second detector and a second optical waveguide connecting the second light source and the first detector;
a first prism between the first light source and the first optical waveguide, and a second prism between the second light source and the second optical waveguide; and
A first filter between the first prism and the first optical waveguide, and a second filter between the second prism and the second optical waveguide,
The light emitted from the first light source passes through the first filter and is provided into the first optical waveguide,
The light emitted from the second light source passes through the second filter and is provided into the second optical waveguide,
The first filter includes a first upper mirror, a first lower mirror, and a first spacer between the first upper mirror and the first lower mirror,
Further comprising a first buffer layer between the first filter and the first optical waveguide,
The second filter includes a second upper mirror, a second lower mirror, and a second spacer between the second upper mirror and the second lower mirror,
Further comprising a second buffer layer between the second filter and the second optical waveguide,
The first upper mirror includes a first filter film in contact with the first prism and a second filter film in contact with the first spacer,
The first lower mirror includes a third filter film in contact with the first spacer and a fourth filter film in contact with the first buffer layer,
The first filter membrane and the fourth filter membrane have the same thickness and refractive index,
The second filter membrane and the third filter membrane have the same thickness and refractive index,
The second upper mirror includes a fifth filter film in contact with the second prism and a sixth filter film in contact with the second spacer,
The second lower mirror includes a seventh filter film in contact with the second spacer and an eighth filter film in contact with the second buffer layer,
The fifth filter membrane and the eighth filter membrane have the same thickness and refractive index,
An optical communication network system wherein the sixth filter film and the seventh filter film have the same thickness and refractive index.
delete According to claim 17,
An optical communication network system further comprising anti-reflection films covering lower surfaces and inclined surfaces of each of the first and second prisms.
According to claim 17,
An optical communication network system wherein each of the first light source and the second light source includes a lens.

Images