Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
  • G02B6/122—Basic optical elements, e.g. light-guiding paths
  • G02B6/124—Geodesic lenses or integrated gratings
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
  • G02B6/13—Integrated optical circuits characterised by the manufacturing method
  • G02B6/136—Integrated optical circuits characterised by the manufacturing method by etching
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
  • G02B6/4206—Optical features
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
  • G02B2006/12083—Constructional arrangements
  • G02B2006/12097—Ridge, rib or the like
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
  • G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
  • G02B2006/12083—Constructional arrangements
  • G02B2006/12107—Grating
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements

Definitions

• the invention relates to photonics integrated chips, optical components with such chips and method for their preparation.
• photonically integrated chips is understood to mean integrated chips which have a substrate and material layers (eg grown or deposited) located thereon and in which one or more photonic components (eg waveguides, couplers, etc.) in one or more of the material layers , etc.) are integrated.
• material layers eg grown or deposited
• photonic components eg waveguides, couplers, etc.
• the two components there are on the one hand the possibility to place the two components next to each other and to couple the light in the horizontal plane of the waveguide, including Butt Coupling ge ⁇ Nannt.
• the components can be placed on top of each other to transmit the light vertically or nearly vertically to the plane of the waveguide.
• the light incident on the waveguide, at a small angle to the surface normal is generally deflected via a grating coupler into the waveguide and carried on in it.
• the present methods entail great losses because the mostly used grating couplers have only a limited angular acceptance.
• these other optical components have in coupling out of light from a waveguide in other optical components, such as.
• fibers eg, glass or polymer fibers
• fibers also have an angular acceptance.
• the proportions of radiation that occur outside of the angular acceptance, are not in z. B. the waveguide or the fiber coupled and are lost.
• These losses are greater the more divergent or convergent the incident light is. Due to the beam divergence, the coupling losses can increase with a greater distance between the coupling elements, if the aperture of the target coupling element is insufficient.
• the obe ⁇ ren material layers of optical components technical terminology also called "back-end of line" of the device, with examples game, five metal layers have a thickness of about 20 .mu.m. When propagating a divergent light beam over this distance, its beam diameter increases significantly.
• a fiber is nowadays interposed between the light source and the grating coupler of the waveguide.
• the light is first coupled into the fiber, and coupled, and the walls ⁇ ren fiber end of the fiber coupled via the grid ⁇ couplers in the waveguide. This is associated with large production costs, additional components and coupling losses at the input and output facets of the fiber [1].
• micro-optics e.g. As lenses
• this method requires high Production costs with additional components (eg injection molding or glass microlenses), production steps and associated tolerances and poor scalability [2].
• Another way consists in the use of lenses that are etched into the exit facet of a laser, to collimate the light emit ⁇ oriented or focus before it emerges from the laser [3].
• a photonic integrated chip with the features according to the preamble of claim 1 is known from Veröffentli ⁇ chung "A polarization-diversity wavelength duplexer circuit in silicon-on-insulator photonic wires" (Wim Bogaerts, Dirk Taillaert, Pieter Dumon, Dries Van Thourhout, Roel Baets, 19 February 2007 / Vol 15, No 4 / OPTICS EXPRESS 1567) ⁇ be known...
• the invention is based on the object of the last-mentioned prior art to improve the achievable coupling efficiency in the chip in a simple manner.
• the invention provides that layers of material ⁇ within an opening located above or below the optical grating coupler Ma ⁇ terial Anlagen of the chip or in multiple located above or below the optical grating coupler or on the backside of the substrate an optical diffraction and refraction structure is integrated, the one Beam shaping of the radiation before coupling into the waveguide or after coupling out of the waveguide makes.
• the wave front of the incident light can be formed in an arbitrary wavefront of the emerging light trans ⁇ .
• the collimation and focusing of the incident light can be made possible if the diffraction and refraction structure is converted according to the principle of a discretized lens or Fresnel lens.
• the beam divergence of the incident light can be reduced to such an extent that the entire beam propagates within the acceptance angle of the grating coupler and can be coupled into the waveguide with only very small losses.
• the diffraction and refraction structure can also be used to adapt the diameter of the incident light to the aperture of the grating coupler, thereby minimizing losses due to beam portions that do not strike the grating coupler.
• the incident light can thereby ⁇ example, both of a fiber (eg. As glass or polymer fibers), another photonic integrated chip, as well as directly from a laser (eg. B. HCSEL, VCSEL) originate.
• the extraction of light via the diffraction and refraction structure of upper material layers of the chip (the so-called "backend of line") te in a second optical Komponen ⁇ , such.
• the diffraction and refraction structure can be adapted so that a beam divergence of the emergent
• the optical diffraction and refraction structure is preferably formed by steps in one or more material layers of the chip located above or below the optical grating coupler or at least also includes such steps.
• the waveguide is preferably a ridge waveguide comprising a ⁇ be formed in a wave-guiding layer of material of the chip rib.
• the optical diffraction and refraction structure is integrated in such an embodiment, preferably in one or more above or below the rib befind ⁇ Licher layers of the chip.
• the substrate of the chip is preferably a semiconductor material, such as silicon.
• the chip is particularly preferably based on SOI (silicon on insulator) material.
• SOI silicon on insulator
• the grating coupler may be a one-dimensional or two-dimensional grating coupler.
• the grating is preferably a Bragg grating or comprises a sol ⁇ ches preferably at least also.
• the diffraction and refraction structure is preferably configured kanndi ⁇ dimensional and is preferably in a plane parallel to the waveguiding material layer or the wel ⁇ lengeden material layers. With a view to an optimum coupling efficiency, it is considered particularly advantageous if the diffraction and Bre ⁇ monitoring structure is two-dimensional location dependent, depending in one dimension along the longitudinal direction from the place of the waveguide and in a perpendicular dimension depending on the location perpendicular to the longitudinal direction of the waveguide.
• the diffraction and refraction structure preferably forms a two-dimensional Fresnel lens.
• the waveguide is preferably an SOI rib waveguide with a rib which is formed in one of a silicon dioxide layer be ⁇ -sensitive wave-conducting silicon layer of an SOI material and whose longitudinal direction ent ⁇ long the propagation direction of guided in the SOI ridge waveguide radiation extends.
• the diffraction and Bre ⁇ monitoring structure is two-dimensionally arranged and is parallel to the wave-conducting silicon layer in a plane where ⁇ is two-dimensionally spatially ⁇ depending on the diffraction and refraction structure, namely in one dimension depending on the location along the longitudinal direction of the rib of the SOI waveguide and in a dimension perpendicular thereto depending on the location perpendicular to the longitudinal direction of the rib of the SOI waveguide.
• ribs In addition to the rib are preferably webs whose layer height is smaller than that of the rib.
• the wave-guiding silicon layer has been removed at least in sections.
• the invention also relates to an optical component having a photonically integrated chip.
• a component preferably comprises a fiber whose fiber end is coupled to the side of the optical diffraction and refraction structure facing away from the grating coupler, wherein the longitudinal direction of the fiber in the region of the fiber end is almost perpendicular to the waveguide or waveguide
• Layers of the chip is aligned.
• the optical component may comprise a radiation emitter which is coupled to the side facing away from the grating coupler of the optical diffraction and refraction structure, wherein the radiation direction of the radiation emitter is aligned almost perpendicular to the one or more waves ⁇ leading layers of the chip.
• the optical component may comprise a radiation detector, which is coupled to the side of the optical diffraction and refraction structure facing away from the grating coupler, the active receiving surface of the radiation detector being aligned parallel to the waveguiding layer (s) of the chip.
• the invention also relates to a method for
• a photonic integrated chip comprising a substrate and a plurality of positioned on a top surface of the substrate ⁇ applied material layers, wherein is integrated in the process, an optical waveguide in one or more wellenware- leaders material layers of the chip and formed in the optical waveguide, a grating coupler is which deflects radiation guided in the waveguide in the direction of the layer plane of the wave guiding beam. the material layer or the wave-guiding material layers out or a beam deflection of radiation to be coupled into the waveguide in the direction of the layer plane of the wave-guiding material layer or the wave-guiding ma- material layers into effected.
• optical diffraction and refraction structure is preferably produced by etching steps in one or more material layers of the chip located above or below the optical grating coupler, or preferably at least also comprises etching steps.
• one or more lithographs are used in advance. Fie suitse performed for applying one or more etching masks.
• the number of etching steps and thus the steps graduated in depth can be kept low, whereby the production costs can remain low.
• the Realisie ⁇ tion of a binary diffractive and refractive structure is possible, also called phase plate which achieves a per ⁇ but slightly lower coupling efficiency with the same aperture, as ei ⁇ ne diffraction and refraction structure with multiple stages. If a sufficient aperture can be realized on the chip, however, a sufficient coupling efficiency can easily be achieved even with a binary structure.
• the individual stages of the generated optical diffraction and refraction structure in both spatial directions of the plane of the substrate can be carried out independently of each other.
• a spatial separation of the incident light beam into individual separated partial beams can take place, which can be continued independently of each other.
• Such a separation can also be implemented via different polarization directions of the separated partial beams.
• the invention will be explained in more detail with reference tojurisbeispie ⁇ len; thereby show by way of example ment an exemplary embodiment of an optical Bauele, which is equipped with a diffractive and refractive structural structure,
• Figure 2 shows an embodiment of a photonic integrated circuit chip, in which a diffraction and Bre ⁇ monitoring structure is a Fresnel lens,
• FIG. 3 shows the structure of the Fresnel lens according to FIG.
• FIG. 4 shows an embodiment of a photonic integrated circuit chip, in which a diffraction and Bre ⁇ monitoring structure is carried out in several stages
• FIG. 5 shows a further embodiment of a photo ⁇ cally integrated chip having a plurality of stages executed diffraction and refraction structure
• Figure 6 shows an embodiment for an optical Bauele ⁇ ment in which a diffractive and refractive structure of a photonic integrated chips is performed in one stage from ⁇ and a two-dimensional binary Stu ⁇ fenlinse forms
• FIG. 7 shows the binary stepped lens according to FIG. 6 in one
• FIG. 8 shows an exemplary embodiment of an SOI waveguide which is used for the optical components according to FIGS. 1 and 6 or the photonically integrated chips according to FIGS. 2 and 4 to 5 is suitable, and for example with reference to the photonically integrated chip according to Figure 2, and
• FIG. 9 shows a further exemplary embodiment of an SOI waveguide which is suitable for the optical components according to FIGS. 1 and 6 or the photonically integrated chips according to FIGS. 2 and 4 to 5, by way of example with reference to the photonically integrated chip according to FIG ,
• FIG. 1 shows an exemplary embodiment of an optical component 1 which comprises a photonically integrated chip 2 or may be formed solely by it.
• the optical component 1 has, in addition to the chip 2, a radiation-emitting component 3, for example in the form of a laser or a radiation emitter.
• the photonically integrated chip 2 comprises a substrate 20, on whose upper side 21 a plurality of material layers is arranged.
• a silicon dioxide layer 30 on which in turn a wave-guiding silicon layer 40 is arranged.
• the substrate 20, the silicon dioxide layer 30 and the wave-guiding silicon layer 40 may be formed by a so-called SOI (Silicon on Insulator) material, which is commercially available prefabricated.
• a Rippenwel ⁇ lenleiter 50 is provided, which can for example be formed by etching the wave-conducting silicon layer 40th
• a grating coupler 60 in the form of a Bragg grating in combination, which has preferably also been prepared by etching the wave-guiding silicon layer 40.
• top layer 80 has a diffraction and Brechungsstruk- structure 100 is integrated, which not nearer Darge ⁇ in the figure 1.
• the diffractive and refractive structure 100 is prepared prior ⁇ preferably by one or more lithography steps and using one or more etching steps; Exemplary embodiments will be explained in more detail below.
• the optical component 1 according to FIG. 1 can be operated, for example, as follows: With the radiation-emitting component 3, a divergent light beam Pe is generated whose curved wavefront 200 has a divergence.
• the divergent light beam incident on the diffraction and Pe refractive structure 100 which is arranged in the embodiment according to FIG 1 in the cover layer 80 and thus in the so-called "back-end of line" area of the photo ⁇ cally integrated chips. 2
• the diffraction and refraction structure 100 transforms the incident wavefront 200 of the divergent light beam Pe into a planar wavefront 201, which subsequently enters the grating coupler 60 and couples it via this into the ridge waveguide 50.
• the guided in the rib waveguide 50 light is indicated in the figure 1 by the reference Pa.
• the diffractive and refractive structure 100 used in the embodiment according to figure 1 to make a beam ⁇ modeling and transform the curved wavefront 200 in a plane wavefront 201, whereby the efficiency of coupling into the grating 60 and in the ridged waveguide 50 is improved.
• FIG. 2 shows an exemplary embodiment of a diffraction and refraction ⁇ structure 100 that may be used in the photonic integrated chip 2 of the device 1 according to Figure 1 in further detail.
• the diffraction and refraction structure 100 in the exemplary embodiment according to FIG. 2 is formed by a single-stage step profile comprising etched sections 101 and unetched sections 102.
• the arrangement of the etched portions 101 and the unetched portions 102 is selected such that the diffraction and refraction structure 100 forms a Fresnel lens 300.
• FIG. 4 shows a further exemplary embodiment of a diffraction and refraction structure 100 which can be used in the photonically integrated chip 2 of the optical component 1 according to FIG.
• the diffraction and refraction structure 100 is formed by a three-step step profile which has been formed in the upper or top cover layer 80 of the chip 2 by lithography and etching steps.
• the steps ⁇ height and step arrangement of the steps is chosen such that the beam shaping of the divergent light beam Pe with a view to planar as possible wavefront 201 and optimum coupling efficiency to the grating 60 and to Rippenwel ⁇ lenleiter 50 is possible favorable.
• FIG. 5 shows a further exemplary embodiment of a diffraction and refraction structure 100 which can be used in the photonically integrated chip 2 of the optical component 1 according to FIG.
• a multi-stage lens profile has been formed in the upper cover layer 80 of the photonic integrated chip 2 by a plurality of lithographic and etching steps, which may include, for example, thirteen Stu ⁇ fen.
• the stepped profile and the outer Formge ⁇ bung of the lens is selected such that the Koppel strigs- in the direction of the grating coupler is possible optimal level 60 and in the direction of the ridge waveguide 50th
• FIG. 6 shows a further exemplary embodiment of an optical component 1 which is equipped with a photonically integrated chip 2.
• the optical component 1 comprises a radiation ⁇ receiving component 4, which may be, for example, a radiation detector.
• the photonic integrated chip 2 includes a substrate 20, a buried silicon dioxide layer 30, a wave-guiding Si ⁇ lizium Anlagen 40, an intermediate layer 70 and an upper cover layer 80, in which a diffractive and refractive structural ⁇ structure is provided 100a.
• a rib waveguide 50 and a grating coupler 60 are integrated, preferably by etching.
• the diffraction and refraction structure 100a in the cover layer 80 is formed by a single-stage step profile or a binary step filter comprising etched sections 101 and unetched sections 102.
• the optical component 1 according to FIG. 6 can be operated, for example, as follows:
• a light beam Pe which is guided in the ridge waveguide 50, passes to the grating coupler 60, which decouples the light beam Pe and deflects in the direction of the radiation-receiving component 4.
• the deflected beam preferably has ei ⁇ ne plane wavefront two hundred and first
• the planar wavefront 201 reaches the diffraction and refraction structure 100a, which performs beamforming and converts the formerly planar wavefront 201 into a convergent wavefront 203 with a divergence ⁇ .
• the resulting con ⁇ vergente light beam is indicated in the figure 6 with the reference Pa.
• FIG. 7 shows a diffraction and refraction structure 100a which can be produced with only one etching step and has etched portions 101 and unetched portions 102.
• the diffraction and refraction structure 100a forms a binary step lens 400.
• FIG. 8 shows an exemplary embodiment of an SOI waveguide in the form of an SOI rib waveguide, which is suitable for the optical components according to FIGS. 1 and 6 or the photonically integrated chips according to FIGS. 2 and 4 to 5, in cross section, and Although by way of example with reference to the photonically integrated chip according to FIG. 2
• FIG. 8 shows the substrate 20, on the upper side 21 of which a plurality of material layers is arranged.
• the silicon dioxide layer 30 On the upper side 21 of the substrate 20 there is, inter alia, the silicon dioxide layer 30, on which in turn the wave-guiding silicon layer 40 is arranged.
• the substrate 20, the Sili ⁇ ziumdioxid für 30 and the wave-guiding layer of silicon 40 are ge ⁇ represented by an SOI (silicon on insulator) material.
• a Rippenwel ⁇ lenleiter 50 is provided; the rib width of the rib 51 is indicated by the reference B in FIG.
• the webs 52 and 53 the web height or layer height is smaller than that of the rib 51.
• the Ausbrei ⁇ power direction of the light beam Pa according to FIG 2 is perpendicular to the image plane ⁇ right in Figure 8 and may be directed out of the image plane or in the image plane of projection; in the embodiment according to FIG. 8, it is assumed by way of example that the light beam Pa is directed into the image plane.
• the diffraction and refraction structure 100 is integrated, which is designed two-dimensional and performs beam shaping in two axes, namely along the direction of arrow or along the propagation direction of the light beam Pa according to Figures 2 and 8 - ie along the longitudinal direction of the rib waveguide 50 and also perpendicular thereto, ie along the direction of the arrow Y in FIG. 8.
• the diffraction and refraction structure 100 is preferably produced by means of one or more lithography steps and by means of one or more etching steps.
• FIG. 8 also shows that the diffraction and refraction structure 100 along the direction of the arrow Y is formed by a single-stage step profile comprising etched sections 101 and unetched sections 102.
• the arrangement of the etched portions 101 and the unetched portions 102 is, for example, selected such that the diffraction and refraction structure 100 forms a two-dimensional Fresnel lens 300.
• the etched portions 101 and the non-etched from ⁇ sections 102 of the diffractive and refractive structure 100 fabric ⁇ te Fresnel lens 300 is shown in Figure 3 in a plan view in further detail.
• the diffraction and refraction structure 100 along the direction of the arrow Y can also be multi-level, such as this has been explained in connection with FIGS. 4 and 5.
• FIG. 9 shows a further exemplary embodiment of an SOI waveguide which is suitable for the optical components according to FIGS. 1 and 6 or the photonically integrated chips according to FIGS. 2 and 4 to 5, in cross section, specifically by way of example by means of photonics integrated chips according to FIG. 2
• the substrate 20 on whose upper ⁇ page 21 is a plurality of material layers.
• the substrate 20, the Sili ⁇ ziumdioxid für 30 and the wave-guiding silicon layer 40 form SOI (silicon on insulator) material.
• a rib waveguide 50 is provided in the wave-guiding silicon layer 40; the rib width of the rib 51 is indicated by reference B in FIG.
• the silicon has been completely removed in sections, for example, has been etched away, so that the webs 52 and 53 shown in FIG. 8 are missing.
• one or more upper material layers preferably the uppermost material layer (cover layer 80), of the photonically integrated chip 2, that is to say the so-called "backend of line” region of the photonically integrated chip, are lithographically phically generated optical diffraction and refractive structure 100 introduced for beam shaping of light.
• ⁇ as step-like structures in the top or one or more upper layers of material are etched.
• the z. B. may be limited by the number of available exposure masks, structures can be realized with one or more graduated in depth levels.
• These structures act in their entirety as a refractive and diffractive beam shaping element for a particular Wellenatnbe ⁇ rich through specific spatial variation of refractive index.
• the etched and non-etched regions have different refractive indices.
• the run times and Ausbrei ⁇ tung directions of light waves through these different loading ranges are thus different, so that the wave front of the incident light wave is deformed after propagation through the diffraction and refraction structure.
• This effect can be used, for example, to collimate or even focus the light beam, before moving it to a lower layer of the chip 2, the so-called "front end of line" region of the chip, onto the grating coupler 60 in the waveguide Material layer hits.
• the diffractive and refractive structure 100 is preferably manufactured by a photo-lithographic exposure and etching process that can be combinatorial ⁇ defined with a plasma etch, or by ion beam etching. This process usually takes place at the end of the complete processing of the chip.

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• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Optical Couplings Of Light Guides (AREA)
• Optical Integrated Circuits (AREA)

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• 2014
  • 2014-09-29 DE DE102014219663.9A patent/DE102014219663A1/de not_active Withdrawn
• 2015
  • 2015-09-25 US US15/515,486 patent/US20170242191A1/en not_active Abandoned
  • 2015-09-25 CN CN201580049618.XA patent/CN106796326A/zh active Pending
  • 2015-09-25 DE DE112015004443.4T patent/DE112015004443A5/de not_active Withdrawn
  • 2015-09-25 EP EP15794067.7A patent/EP3201664A1/de not_active Withdrawn
  • 2015-09-25 WO PCT/DE2015/200463 patent/WO2016050242A1/de active Application Filing

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