Laser with edge coupler displaced from substrate

Abstract

The embodiment of the invention relates to a laser with an edge coupler displaced from a substrate. A device includes a semiconductor substrate, a light source displaced from the semiconductor substrate by a first displacement, a first dielectric waveguide displaced from the semiconductor substrate by a second displacement, and a second dielectric waveguide displaced from the semiconductor substrate by a third displacement. The second displacement is greater than the first displacement. The first dielectric waveguide overlaps at least a portion of the light source such that light is adiabatically coupled from the light source into the first dielectric waveguide. The third displacement is greater than the second displacement. The second dielectric waveguide overlaps at least a portion of the first dielectric waveguide such that light is coupled from the first dielectric waveguide into the second dielectric waveguide. The second dielectric waveguide includes an edge coupler configured to couple light out of the second dielectric waveguide.

Description

Technical Field

[0001] The present disclosure relates generally to optical devices, and more particularly to edge coupling of optical devices. Background Art

[0002] Many photonic applications require repeatable and low-loss optical coupling to a light source, such as a laser configured to generate light, a semiconductor optical amplifier (SOA) configured to amplify and propagate light, or a modulator configured to modulate and propagate light. In many such applications, it is beneficial that the light source can be manufactured in large quantities. Therefore, silicon photonics technology (such as hybrid lasers) can be used to achieve low-cost, high-volume manufacturing of light sources at the wafer level. However, light sources formed in silicon often face various design limitations in outcoupling light to receiving devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The following description includes a discussion of the drawings with diagrams given by examples of embodiments disclosed herein. The drawings should be understood by way of example and not limitation. As used herein, reference to one or more "examples" or "embodiments" should be understood to describe the specific features, structures or characteristics included in at least one implementation of the subject matter of the present invention in at least some cases. Therefore, phrases such as "in one example", "in some examples", "in some embodiments", "in one embodiment" or "in an alternative embodiment" that appear herein describe various embodiments and implementations of the subject matter of the present invention, and do not necessarily all refer to the same embodiment. However, they are not necessarily mutually exclusive either. In order to easily identify the discussion of any particular element or action, one or more most significant bits in the figure mark can refer to the accompanying drawings ("figures") to which the element or action is first introduced.

[0004] Figure 1 illustrates a side cross-sectional view of a device showing displacement of components of the device from a semiconductor substrate according to some examples;

[0005] Figure 2 The diagram shows some examples of Figure 1 a side cross-sectional view of a device showing four regions of adiabatic mode coupling between components of the device;

[0006] Figure 3 A bottom plan view showing a Figure 1 an overlap of a first dielectric waveguide and a second dielectric waveguide of a device;

[0007] Figure 4A The diagram shows some examples of Figure 1 The device follows Figure 3 A front cross-sectional view of line AA;

[0008] Figure 4B The diagram shows some examples of Figure 1 The device follows Figure 3 A front cross-sectional view of line BB; and

[0009] Figure 5 A flowchart showing operations of a method of fabricating a device is illustrated, according to some examples.

[0010] The following is a description of certain details and implementations, including descriptions of the accompanying drawings, which may depict some or all of the embodiments described below, as well as discuss other potential embodiments or implementations of the inventive concepts presented herein. An overview of the embodiments of the present disclosure is provided below, followed by a more detailed description with reference to the accompanying drawings. DETAILED DESCRIPTION

[0011] In the following description, for the purpose of explanation, many specific details are set forth to provide an understanding of various embodiments of the subject matter of the present invention. However, it is clear to those skilled in the art that the embodiments of the subject matter of the present invention can be practiced without these specific details. In general, well-known instruction examples, structures and techniques are not necessarily shown in detail.

[0012] As mentioned above, light sources formed in silicon may face various design constraints related to the outcoupling of light. In SOI (Silicon on Insulator) photonic platforms with buried insulators, it is beneficial to keep the laser or SOA close to the semiconductor substrate for heat dissipation. However, if an edge coupler is used to outcouple light to a receiving device, it can be beneficial to use an edge coupler with low loss and a large mode field diameter (MFD), and such edge couplers tend to perform better at a greater distance from the semiconductor substrate. The farther the edge coupler is from the substrate, the larger the output field and the less substrate leakage losses the edge coupler will experience.

[0013] Existing approaches to SOI photonic platforms with edge couplers often ignore heat dissipation issues, leading to thermal limitations, and / or ignore edge coupling issues, leading to optical performance limitations and reduced power efficiency. One such approach is described by Xiang, C., Jin, W., Terra, O., et al. in “3D integration enables ultralow-noise isolator-free lasers in silicon photonics (Nature 620, 78–85 (2023). https: / / doi.org / 10.1038 / s41586-023-06251-w (hereinafter “Xiang”))”. The approach described in Xiang uses ultralow-loss (ULL) dielectric waveguides with highly delocalized modes to achieve relatively large modes at the edge coupler. However, Xiang ignores heat dissipation issues and places the laser farther from the silicon substrate than previous approaches. The nature of Xiang’s ULL waveguide coupling and other components requires very long length scales, which are larger than typical photonic integrated circuit (PIC) dimensions. Therefore, the method described in Xiang results in low output power and requires a larger PIC (thus increasing manufacturing costs) and two bonding steps (further increasing costs). Other methods have shown similar limitations.

[0014] Thus, the examples described herein may attempt to address one or more technical issues associated with the design and manufacture of silicon photonic light sources, such as hybrid silicon lasers and SOAs. In particular, some examples may provide a device in which a laser or SOA is integrated on top of an SOI substrate and close to a semiconductor substrate to aid in heat dissipation, but an edge coupler is located farther from the semiconductor substrate, thereby allowing the use of a relatively low-loss, large-MFD edge coupler. In some examples, light from a light source propagates through a first dielectric waveguide (e.g., a relatively thick silicon nitride layer) relatively close to a semiconductor substrate, and then is coupled to a second dielectric waveguide (e.g., another thinner silicon nitride film) relatively far from the semiconductor substrate via fast adiabatic coupling, thereby enabling the two dielectric waveguides to be arranged in a relatively compact configuration. The second dielectric waveguide terminates in an edge coupler that extends an optical mode. The edge coupler has a relatively large MFD, which is achieved by its spatial displacement from the semiconductor substrate, thereby reducing edge coupling losses to external optical devices.

[0015] Unlike existing approaches, examples described herein may include multiple passive waveguide layers that may be fabricated as part of a single platform (eg, a single chip).

[0016] Figure 11 is a side cross-sectional view of device 100, which shows the vertical displacement of components of device 100 from semiconductor substrate 102. In some examples, device 100 is a device having a buried insulator ( Figure 1 A photonic device (also called a photonic platform) (not shown) such as an SOI device.

[0017] The device 100 may be fabricated as layers stacked along a lamination axis 132 defining the vertical dimension of the drawing. Figure 1 The view of FIG. 1 shows that the device 100 extends from left to right in the longitudinal direction 130. The horizontal axis (as shown below Figure 3 The bottom view of Figure 1 130. It should be understood that the drawings of device 100 are not drawn to scale and do not depict the entire device. In some examples, the lateral and / or longitudinal dimensions of device 100 and its various components can be much larger than the height of the components along lamination axis 132, perhaps one or more orders of magnitude larger. For example, the height of the entire device 100 along lamination axis 132 can be less than 10 microns (μm), while the length of the shown portion of device 100 extending in the longitudinal direction 130 can be hundreds of μm, or even several millimeters (mm). For clarity, the views shown are simplified.

[0018] The device 100 includes a semiconductor laser 112 fabricated relatively close to a semiconductor substrate 102 (e.g., silicon) to improve thermal performance. The laser 112 includes, from top to bottom, a ridge or layer of p-type material 106 above an active region 108 (e.g., a multiple quantum well emitter region of the laser), below which is a layer of n-type material 110. Below the n-type material 110 is a silicon waveguide 114 having an upper portion 116 and a lower portion 118. In the example shown, the lower portion 118 extends further in a longitudinal direction 130 than the upper portion 116. In the examples described herein using a laser or other light source with a waveguide, the lowest surface of the light source (such as a bottom surface of the waveguide) defines a first displacement 124.

[0019] The bottom of the lower portion 118 of the silicon waveguide 114 is displaced from the semiconductor substrate 102 by a first displacement 124 filled with one or more insulating dielectric material layers 104, such as oxide. In some examples, the first displacement 124 is a distance less than 1.5 μm, such as 1270 nanometers (nm).

[0020] A relatively thick dielectric waveguide (such as a silicon nitride waveguide) (as shown by the first dielectric waveguide 120) is formed slightly above the laser waveguide layer (e.g., above the upper surface of the lower portion 118 of the silicon waveguide 114) so ​​that the bottom surface of the first dielectric wave 120 is displaced from the semiconductor substrate by a second displacement 126. In some examples, the second displacement 126 causes the first dielectric waveguide 120 to be a distance from a portion of the laser 112 (such as the active region 108 of the laser 112) in the longitudinal direction 130. For example, the second displacement 126 can be about 1.5 μm, such as 1540 nm. The gap between the lower portion 118 of the silicon waveguide 114 and the first dielectric waveguide 120 can be formed by one or more additional insulating dielectric material layers 104. Thus, in some examples, the lower surface of the first dielectric waveguide 120 can be approximately the same distance from the semiconductor substrate 102 as one or more layers of the light source; however, the bottom surface of the light source (in this case, the lower surface of the lower portion 118 of the silicon waveguide 114) is at a first displacement 124 from the semiconductor substrate 102, which is less than a second displacement 126 of the first dielectric waveguide 120.

[0021] One or more additional insulating dielectric material layers 104 are also deposited over the first dielectric waveguide 120. In some examples, these additional insulating dielectric material layers 104 define a gap of about 1 μm or more over the first dielectric waveguide 120. A thinner second dielectric waveguide (which may also be a silicon nitride waveguide) (shown as second dielectric waveguide 122) is formed over the gap and adiabatically coupled to the first dielectric waveguide 120. Thus, the second dielectric waveguide 122 may be more than 1 μm further from the semiconductor substrate 102 than the first dielectric waveguide 120, with the bottom surface of the second dielectric waveguide 122 displaced from the semiconductor substrate 102 by a third displacement 128. In some examples, the third displacement 128 is at least 3 μm, such as 3180 nm. The relatively large third displacement 128 may allow an edge coupler with a large MFD to be incorporated into the second dielectric waveguide 122 , with lower loss and more repeatable coupling than when the second dielectric waveguide 122 is closer to the semiconductor substrate 102 .

[0022] Figure 2 Shown with Figure 1 FIG. 1 is a side cross-sectional view of the same device 100 in FIG. 1 . However, Figure 2 Four adiabatic mode coupling regions between components of the device 100 are shown, as well as an edge coupler 210 defined by a portion of the second dielectric waveguide 122 .

[0023] Four adiabatic mode couplers (AMCs) are shown from left to right in the longitudinal direction 130. In the first AMC 202, light generated by the active region 108 of the laser 112 is adiabatically coupled into the silicon waveguide 114. In the second AMC 204, light propagating through the silicon waveguide 114 is adiabatically coupled downward from the upper portion 116 into the lower portion 118. In the third AMC 206, light propagating within the lower portion 118 is adiabatically coupled upward into the first dielectric waveguide 120. In the fourth AMC 208, light propagating within the first dielectric waveguide 120 is adiabatically coupled upward into the second dielectric waveguide 122.

[0024] The third AMC 206 may be considered an overlap of the lower portion 118 and the first dielectric waveguide 120 with respect to the lamination axis 132. In some examples, the third AMC 206 extends in the longitudinal direction 130 for a length that is less than 120 μm.

[0025] Similarly, the fourth AMC 208 can be viewed as an overlap of the first dielectric waveguide 120 and the second dielectric waveguide 122 with respect to the lamination axis 132. Figure 3 Describe the length and nature of the overlap in the longitudinal direction 130 .

[0026] The right side portion of the second dielectric waveguide 122 defines an edge coupler 210, as will be described below with reference to Figure 3 Described in more detail.

[0027] Thus, in some examples, the device 100 includes a semiconductor substrate 102, a light source (e.g., a laser 112) displaced from the semiconductor substrate 102 by a first displacement 124 relative to a lamination axis 132, a first dielectric waveguide 120 displaced from the semiconductor substrate 102 by a second displacement 126 relative to the lamination axis 132, and a second dielectric waveguide 122 displaced from the semiconductor substrate 102 by a third displacement 128 relative to the lamination axis 132. The second displacement 126 is greater than the first displacement 124, and the third displacement 128 is greater than the second displacement 126. The first dielectric waveguide 120 overlaps at least a portion of the light source relative to the lamination axis 132 such that light is adiabatically coupled from the light source into the first dielectric waveguide 120. The second dielectric waveguide 122 overlaps at least a portion of the first dielectric waveguide 120 relative to the lamination axis 132 such that light is coupled from the first dielectric waveguide 120 into the second dielectric waveguide. The second dielectric waveguide 122 includes an edge coupler 210 configured to couple light out of the second dielectric waveguide 122 in a longitudinal direction 130 that is perpendicular to the lamination axis 132 .

[0028] In some examples, third displacement 128 is at least 1 micron greater than second displacement 126 .

[0029] In some examples, third displacement 128 is at least 3 microns.

[0030] In some examples, the light source includes a hybrid silicon laser 112 .

[0031] In some examples, device 100 includes multiple layers stacked with respect to a lamination axis.

[0032] In some examples, first displacement 124 , second displacement 126 , and third displacement 128 each include one or more insulating dielectric material layers 104 .

[0033] In some examples, the hybrid silicon laser 112 includes a III-V semiconductor structure (e.g., p-type material 106, active region 108, and n-type material 110), and a silicon waveguide 114 displaced a first displacement 124 from the semiconductor substrate 102. The first dielectric waveguide 120 overlaps a portion (e.g., lower portion 118) of the silicon waveguide 114 relative to the lamination axis 132.

[0034] In some examples, the first dielectric waveguide 120 and a portion of the III-V semiconductor structure (eg, at least the active region 108 ) are equally displaced from the semiconductor substrate 102 relative to the lamination axis 132 .

[0035] Figure 3 is a bottom plan view showing the overlap of the first dielectric waveguide 120 and the second dielectric waveguide 122 and showing the geometry of the edge coupler 210 . Figure 3 The plane of the bottom view is defined by the longitudinal direction 130 and the transverse axis 302 ; the view is along the lamination axis 132 .

[0036] It should be understood that Figure 3 Only the rightmost portion of the first dielectric waveguide 120 is shown in FIG. The first dielectric waveguide 120 extends to the left (with respect to the longitudinal direction 130 ) for a considerable distance, including a portion of the first dielectric waveguide 120 overlapping the silicon waveguide 114 within the third AMC 206 .

[0037] As mentioned above Figure 2 As described, the overlap of the first dielectric waveguide 120 and the second dielectric waveguide 122 defines a fourth AMC 208. Within the fourth AMC 208, the first dielectric waveguide 120 defines a plurality of segments that taper from wide to narrow in the longitudinal direction 130. In the example shown, each segment tapers linearly in the longitudinal direction 130, and the size and taper of each segment are defined by constraints on the diameter of the mode of light propagated by the first dielectric waveguide 120. In the example shown, the segments have a length L extending in the longitudinal direction 130. T0 304, L TE 306, L T1 308 and L TM 310.

[0038] Likewise, within the fourth AMC 208, the second dielectric waveguide 122 defines a number of segments that overlap with segments of the first dielectric waveguide 120. In the example shown, the four segments of the second dielectric waveguide 122 are arranged along a length L T0 304, L TE 306, L T1 308 and L TM 310 overlaps with four segments of the first dielectric waveguide 120. The segments of the second dielectric waveguide 122 are wider in the longitudinal direction 30 compared to the segments of the first dielectric waveguide 120 that are narrower in the longitudinal direction 130 to increase the extent to which light propagating in the first dielectric waveguide 120 is outcoupled to the second dielectric waveguide 122 in the fourth AMC 208.

[0039] In some examples, the edge coupler 210 acts as a spot size converter (SSC). Within the length of the edge coupler 210, the second dielectric waveguide 122 defines a plurality of segments that narrow in the longitudinal direction 130, thereby squeezing out the mode of light propagating within the second dielectric waveguide 122. In the example shown, the segments of the edge coupler 210 have a length L 3 312, L 2 314 and L 1 316. As with the narrowed section of the first dielectric waveguide 120 within the fourth AMC 208, the size of the narrowed section of the edge coupler 210 is defined by the constraints on the diameter of the mode of light propagating through the edge coupler 210.

[0040] Thus, in some examples, the edge coupler 210 of the second dielectric waveguide 122 includes a plurality of segments, with the width of each segment decreasing as the segment extends in the longitudinal direction 130 .

[0041] In some examples, the first dielectric waveguide 120 includes a plurality of segments, and the width of each segment increases as the segment extends in the longitudinal direction 130 .

[0042] In some examples, the first dielectric waveguide 120 and the second dielectric waveguide 122 each include silicon nitride.

[0043] Various examples may use different sizes for the various segments depending on design considerations, such as the intended application of the device 100 .

[0044] In a first example, the device 100 is coupled to a lens at the right (longitudinal) tip of the edge coupler 210, and the lens propagates the light received from the edge coupler 210 into free space. Such a configuration can be used in applications such as light detection and ranging (LIDAR) arrays, where light is coupled into the air through a lens, and the beam propagates in the air, hits a target, and returns at a slightly offset angle from the outgoing beam. In such applications, light outcoupled from the edge coupler 210 with a large mode size can provide improved mode overlap and lower losses for the returning beam.

[0045] The first exemplary device 100 described above may be designed to be implemented in L TE 306 and L TM The first example device 100 may have a tip width of 0.25 μm (the tip width of the rightmost tip of the edge coupler 210) and a length L of 90 μm. 1 316. It can be configured to TE 306: 7.9 μm horizontal (along horizontal axis 302) MFD(y), 7.1 μm vertical (along lamination axis 132) MFD, 0.9 circularity (MFD(z) / MFD(y)), and 0.8 dB free space coupling loss. It can be configured to TM The following are achieved within a length of 310: horizontal MFD(y) of 8.6 μm, vertical MFD(z) of 7.6 μm, circularity (MFD(z) / MFD(y)) of 0.88, and free-space coupling loss of 1 dB. If the fiber is to be coupled to an edge coupler, then L TE The maximum fiber insertion loss of the 306 section is 1.75dB, while the L TM The maximum fiber insertion loss of the 310 section is 2dB.

[0046] Thus, in some examples, the device 100 further includes a lens optically coupled to the edge coupler 210 in the longitudinal direction 130 to receive light outcoupled by the edge coupler 210 .

[0047] In a second example, the device 100 is coupled to a single mode fiber at the tip of an edge coupler 210. Low optical coupling losses can be achieved due to the improved mode overlap between the output of the edge coupler 210 and the fiber mode size. Therefore, the larger size of the MFD provided at the tip of the edge coupler 210 can provide a wider alignment tolerance for the optical fiber, which can also reduce coupling losses. A lens can optionally be added between the edge coupler and the optical fiber to further reduce optical losses, but it is beneficial to avoid the use of such a lens to reduce cost. The optical losses achieved without a lens are low enough to be sufficient in most applications.

[0048] The second exemplary device 100 described above may be designed to achieve optimal fiber coupling, low insertion loss, and low polarization dependent loss (PDL). The second exemplary device 100 may have a tip width of 0.4 μm (the tip width of the rightmost tip of the edge coupler 210) and a length L of 60 μm. 1 316. It can be configured to TE 306 length: 6.8μm horizontal MFD(y), 4.7μm vertical MFD(z), 0.7 circularity (MFD(z) / MFD(y)), and 0.5dB free space coupling loss. It can be configured to TM The following are achieved within a length of 310: horizontal MFD(y) of 6.8 μm, vertical MFD(z) of 6.3 μm, circularity (MFD(z) / MFD(y)) of 0.95, and free space coupling loss of 0.6 dB. TE The maximum fiber insertion loss of the 306 section is 1.7dB, while the L TM The maximum fiber insertion loss of the 310 section is 1.6dB.

[0049] Therefore, in some examples, the device 100 further includes an optical fiber optically coupled to the lens to receive light from the lens, or an optical fiber optically coupled to the edge coupler to receive light from the edge coupler.

[0050] Figure 4A is through Figure 3 A front cross-sectional view of the device 100 along line AA, which shows the fourth AMC 208 (at length L TE 306). The plane of the drawing is defined by the lamination axis 132 and the transverse axis 302.

[0051] As shown, the first dielectric waveguide 120 is displaced from the semiconductor substrate 102 by filling the insulating dielectric material 104 with a second displacement 126 (e.g., 1540 nm). In this example, the cross-section of the first dielectric waveguide 120 is a trapezoid, and the lateral width at the bottom surface is wider than the width at the top surface. In this example, the angle between the side surface of the first dielectric waveguide 120 and its bottom surface is 84 degrees. The height of the first dielectric waveguide 120 is defined by a first thickness 408, for example, 390 nm.

[0052] Above the first dielectric waveguide 120, the insulating dielectric material 104 fills an intermediate distance 406, e.g., 1250 nm, between the first dielectric waveguide 120 and the second dielectric waveguide 122. The cross-section of the second dielectric waveguide 122 is shown as a rectangle, with a height defined by the second thickness 404, e.g., 160 nm. Finally, an upper distance 402 extends upward from the top surface of the second dielectric waveguide 122 to the top of the device 100, filled with an additional insulating dielectric material layer 104, e.g., a distance of 7875 nm.

[0053] Figure 4B is another front cross-sectional view of the device 100, which is shown through Figure 3 The line BB is taken, which shows the edge coupler 210 near the tip (at length L 1 A front cross section showing the shape and position of the second dielectric waveguide 122 (within the rightmost segment of 316).

[0054] In this view, the third displacement 128 is shown as being filled with insulating dielectric material 104, for example, to a height of 3180 nm. Other dimensions such as Figure 4A shown.

[0055] Thus, in the example shown, the insulating dielectric material 104 in which the first dielectric waveguide 120 and the second dielectric waveguide 122 are embedded extends a total of 11215 nm (the third displacement 128 of 3180 nm + the second thickness 404 of 160 nm + the upper distance 402 of 7875 nm).

[0056] It should be understood that these dimensions are provided as illustrative examples only and that various examples may deviate from these dimensions to achieve different objectives.

[0057] Thus, in some examples, the first dielectric waveguide 120 has a first thickness 408 defined relative to the lamination axis 132 , the second dielectric waveguide 122 has a second thickness 404 defined relative to the lamination axis 132 , and the first thickness 408 is thicker than the second thickness 404 .

[0058] Figure 5Operations of a method 500 for manufacturing a device such as device 100 are shown. Although the example method 500 depicts a particular sequence of operations, the sequence may be changed without departing from the scope of the present disclosure. For example, some of the depicted operations may be performed in parallel or in a different order without substantially affecting the functionality of the method 500. In other examples, different components of an example device or system implementing the method 500 may perform functions substantially simultaneously or in a particular order.

[0059] According to some examples, the method 500 includes forming an insulating dielectric material layer 104 on a semiconductor substrate 102 to define a first displacement 124 at operation 502 .

[0060] According to some examples, the method 500 includes forming a light source (eg, a laser 112 or another light source such as an SOA or an optical modulator) at the first displacement 124 at operation 504 .

[0061] According to some examples, method 500 includes forming an additional insulating dielectric material layer 104 to define a second displacement 126 at operation 506 .

[0062] According to some examples, the method 500 includes forming the first dielectric waveguide 120 at the second displacement 126 at operation 508 .

[0063] According to some examples, method 500 includes forming an additional insulating dielectric material layer 104 to define a third displacement 128 at operation 510 .

[0064] According to some examples, the method 500 includes forming the second dielectric waveguide 122 including the edge coupler 210 at the third displacement 128 at block 512 .

[0065] Although the examples are described as incorporating a laser source, it should be understood that the devices, methods, and structures described herein are equally applicable to other light sources, including SOAs and optical modulators made of compound semiconductors (e.g., III-V materials) on silicon-on-insulator (SOI) substrates. In some examples, two dielectric waveguides (e.g., formed within a silicon nitride layer of the device) are formed at a similar displacement or height to the compound semiconductor, or formed above it (i.e., further from the semiconductor substrate). The dielectric waveguides are adiabatically coupled to the silicon waveguides of the compound semiconductor light source and are used to extend the optical mode size at the edge of the device to achieve lower optical coupling losses to external optical devices.

[0066] Thus, in some examples, the light source comprises a semiconductor optical amplifier.The first dielectric waveguide 120 and a portion of the semiconductor optical amplifier may be equally displaced from the semiconductor substrate relative to the lamination axis.

[0067] In some examples, multiple dielectric waveguide layers can be used at the output edge coupler. Such a configuration can improve the centering of the optical mode in the dielectric stack.

[0068] In some examples, a silicon or silicon compound (e.g., Si 3 N 4 ) made of waveguide.

[0069] Some examples described in this article can achieve the integration of high-volume manufacturable lasers with low-loss large MFD mode couplers. The laser is kept relatively close to the substrate to help dissipate heat. In addition, substrate removal at the edge coupler is not required (which can cause reliability limitations).

[0070] In the present disclosure, terms such as "above," "below," "upper," and "lower," as well as other relative vertical positions, refer to the relative positions of various features relative to the lamination axis 132, along which the layers of the device may be successively formed during the manufacturing process. Similarly, terms such as "length" may refer to distances defined relative to (or relative to) the longitudinal direction 130, and terms such as "lateral" or "width" may refer to distances or directions defined relative to a horizontal axis.

[0071] Other examples of such optical devices may include features of the various examples described herein, as well as combinations or sub-combinations of features.

[0072] In view of the above disclosure, various examples are set forth below. It should be noted that within the scope of the disclosure of the present application, one or more features of the examples given alone or in combination should be considered.

[0073] The following are example embodiments:

[0074] Example 1 is a device, the device comprising: a semiconductor substrate; a light source, which is displaced from the semiconductor substrate by a first displacement relative to a lamination axis; a first dielectric waveguide, which is displaced from the semiconductor substrate by a second displacement relative to the lamination axis, the second displacement being greater than the first displacement, the first dielectric waveguide overlapping at least a portion of the light source relative to the lamination axis, so that light is adiabatically coupled from the light source into the first dielectric waveguide; and a second dielectric waveguide, which is displaced from the semiconductor substrate by a third displacement relative to the lamination axis, the third displacement being greater than the second displacement, the second dielectric waveguide overlapping at least a portion of the first dielectric waveguide relative to the lamination axis, so that light is coupled from the first dielectric waveguide into the second dielectric waveguide; and the second dielectric waveguide comprises an edge coupler, the edge coupler being configured to couple light out of the second dielectric waveguide in a longitudinal direction perpendicular to the lamination axis.

[0075] In Example 2, the subject matter according to Example 1 includes: wherein: the first dielectric waveguide has a first thickness defined relative to the lamination axis; the second dielectric waveguide has a second thickness defined relative to the lamination axis; and the first thickness is thicker than the second thickness.

[0076] In Example 3, the subject matter according to Examples 1-2 includes: wherein: the edge coupler of the second dielectric waveguide includes a plurality of segments, and a width of each segment decreases as the segment extends in the longitudinal direction.

[0077] In Example 4, the subject matter according to Examples 1 to 3 includes: wherein: the first dielectric waveguide includes a plurality of segments, and a width of each segment increases as the segment extends in a longitudinal direction.

[0078] In Example 5, the subject matter of Examples 1 to 4 includes, wherein: the first dielectric waveguide and the second dielectric waveguide each include silicon nitride.

[0079] In Example 6, the subject matter of Examples 1 to 5 includes, wherein: the third displacement is at least 1 micron greater than the second displacement.

[0080] In Example 7, the subject matter of Examples 1 to 6 includes, wherein: the third displacement is at least 3 micrometers.

[0081] In Example 8, the subject matter of Examples 1 to 7 includes, wherein: the light source comprises a hybrid silicon laser.

[0082] In Example 9, the subject matter according to Example 8 includes, wherein: the hybrid silicon laser comprises: a III-V semiconductor structure; and a silicon waveguide displaced from the semiconductor substrate by a first displacement; and the first dielectric waveguide overlaps a portion of the silicon waveguide relative to a lamination axis.

[0083] In Example 10, the subject matter according to Example 9 includes, wherein: a portion of the III-V semiconductor structure and the first dielectric waveguide are equally displaced from the semiconductor substrate relative to a lamination axis.

[0084] In Example 11, the subject matter of Examples 1 to 10 includes, wherein: the light source comprises a semiconductor optical amplifier.

[0085] In Example 12, the subject matter according to Example 11 includes, wherein: a portion of the semiconductor optical amplifier and the first dielectric waveguide are equally displaced from the semiconductor substrate relative to the lamination axis.

[0086] In Example 13, the subject matter of Examples 1 to 12 includes, wherein: the device includes a plurality of layers stacked with respect to a lamination axis.

[0087] In Example 14, the subject matter according to Example 13 includes, wherein: the first displacement, the second displacement, and the third displacement each include one or more layers of insulating dielectric material.

[0088] In Example 15, the subject matter of Examples 1 to 14 includes a lens optically coupled to the edge coupler in a longitudinal direction to receive light outcoupled by the edge coupler.

[0089] In Example 16, the subject matter of Examples 1 to 15 includes an optical fiber optically coupled to the edge coupler to receive the light from the edge coupler.

[0090] Example 17 is a device, the device comprising: a semiconductor substrate; a hybrid silicon laser, which is displaced from the semiconductor substrate by a first displacement relative to a lamination axis; a first dielectric waveguide, comprising silicon nitride, and displaced from the semiconductor substrate by a second displacement relative to the lamination axis, the second displacement causing the first dielectric waveguide and the hybrid silicon laser to at least partially overlap relative to a longitudinal direction perpendicular to the lamination axis, the first dielectric waveguide overlapping at least a portion of the hybrid silicon laser relative to the lamination axis, such that light is adiabatically coupled from the hybrid silicon laser into the first dielectric waveguide; and a second dielectric waveguide comprising silicon nitride, and displaced from the semiconductor substrate by a third displacement relative to the lamination axis, the third displacement being at least 1 micron greater than the second displacement, the second dielectric waveguide overlapping at least a portion of the first dielectric waveguide relative to the lamination axis, such that light is coupled from the first dielectric waveguide into the second dielectric waveguide; and the second dielectric waveguide comprising an edge coupler, the edge coupler being configured to couple light out of the second dielectric waveguide in the longitudinal direction.

[0091] In Example 18, the subject matter according to Example 17 includes, wherein: the third displacement is at least 1 micron greater than the second displacement.

[0092] In Example 19, the subject matter of Examples 17-18 includes, wherein: the third displacement is at least 3 microns.

[0093] Example 20 is a method for manufacturing a device, the method comprising: forming one or more layers of insulating dielectric material on a semiconductor substrate to define a first displacement from the semiconductor substrate, the layers being stacked relative to a lamination axis; forming a light source at the first displacement; forming another one or more layers of insulating dielectric material to define a second displacement from the semiconductor substrate; forming a first dielectric waveguide at the second displacement, the first dielectric waveguide overlapping at least a portion of the light source relative to the lamination axis so that light is adiabatically coupled from the light source into the first dielectric waveguide; forming another one or more layers of insulating dielectric material to define a third displacement from the semiconductor substrate; and forming a second dielectric waveguide at the third displacement, the second dielectric waveguide overlapping at least a portion of the first dielectric waveguide relative to the lamination axis so that light is coupled from the first dielectric waveguide into the second dielectric waveguide; and the second dielectric waveguide includes an edge coupler, the edge coupler being configured to couple light out of the second dielectric waveguide in a longitudinal direction perpendicular to the lamination axis.

[0094] Example 21 is at least one machine-readable medium comprising instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations according to any one of Examples 1-20.

[0095] Example 22 is a device comprising components for implementing any one of Examples 1 to 20.

[0096] Example 23 is a system for implementing any one of Examples 1 to 20.

[0097] Example 24 is a method for implementing any one of Examples 1 to 20.

Claims

1. A device comprising: Semiconductor substrate; a light source displaced from said semiconductor substrate by a first displacement relative to a lamination axis; a first dielectric waveguide displaced from the semiconductor substrate by a second displacement relative to the lamination axis, the second displacement being greater than the first displacement, the first dielectric waveguide overlapping at least a portion of the light source relative to the lamination axis such that light is adiabatically coupled from the light source into the first dielectric waveguide; as well as a second dielectric waveguide displaced from the semiconductor substrate by a third displacement relative to the lamination axis, the third displacement being greater than the second displacement, The second dielectric waveguide overlaps at least a portion of the first dielectric waveguide relative to the lamination axis such that light is coupled from the first dielectric waveguide into the second dielectric waveguide; and The second dielectric waveguide includes an edge coupler configured to couple light out of the second dielectric waveguide in a longitudinal direction perpendicular to the lamination axis.

2. The device according to claim 1, wherein: The first dielectric waveguide has a first thickness defined relative to the lamination axis; the second dielectric waveguide has a second thickness defined relative to the lamination axis; and The first thickness is thicker than the second thickness.

3. The device according to claim 1, wherein: The edge coupler of the second dielectric waveguide includes a plurality of segments, and a width of each segment decreases as the segment extends in the longitudinal direction.

4. The device according to claim 1, wherein: The first dielectric waveguide comprises a plurality of segments, and a width of each segment increases as the segment extends in the longitudinal direction.

5. The device according to claim 1, wherein: The first dielectric waveguide and the second dielectric waveguide each include silicon nitride.

6. The device according to claim 1, wherein: The third displacement is at least 1 micron greater than the second displacement.

7. The device according to claim 1, wherein: The third displacement is at least 3 microns.

8. The device according to claim 1, wherein: The light source includes a hybrid silicon laser.

9. The device according to claim 8, wherein: The hybrid silicon laser comprises: III-V semiconductor structures; and A silicon waveguide is displaced from the semiconductor substrate by the first displacement; and the first dielectric waveguide overlaps a portion of the silicon waveguide with respect to the lamination axis.

10. The device according to claim 9, wherein: A portion of the III-V semiconductor structure and the first dielectric waveguide are equally displaced from the semiconductor substrate relative to the lamination axis.

11. The device according to claim 1, wherein: The light source includes a semiconductor optical amplifier.

12. The device according to claim 11, wherein: A portion of the semiconductor optical amplifier and the first dielectric waveguide are equally displaced from the semiconductor substrate relative to the lamination axis.

13. The device according to claim 1, wherein: The device includes a plurality of layers stacked relative to the lamination axis.

14. The device according to claim 13, wherein: The first displacement, the second displacement, and the third displacement each include one or more layers of insulating dielectric material.

15. The device according to claim 1, further comprising: A lens is optically coupled to the edge coupler in the longitudinal direction to receive the light outcoupled by the edge coupler.

16. The device according to claim 1, further comprising: An optical fiber is optically coupled to the edge coupler to receive the light from the edge coupler.

17. A device comprising: Semiconductor substrate; a hybrid silicon laser displaced from said semiconductor substrate by a first displacement relative to a lamination axis; a first dielectric waveguide comprising silicon nitride and displaced from the semiconductor substrate by a second displacement relative to the lamination axis, the second displacement causing the first dielectric waveguide and the hybrid silicon laser to at least partially overlap relative to a longitudinal direction perpendicular to the lamination axis, the first dielectric waveguide overlapping at least a portion of the hybrid silicon laser relative to the lamination axis such that light is adiabatically coupled from the hybrid silicon laser into the first dielectric waveguide; as well as a second dielectric waveguide comprising silicon nitride and displaced from the semiconductor substrate by a third displacement relative to the lamination axis, the third displacement being at least 1 micron greater than the second displacement, The second dielectric waveguide overlaps at least a portion of the first dielectric waveguide relative to the lamination axis such that light is coupled from the first dielectric waveguide into the second dielectric waveguide; and The second dielectric waveguide comprises an edge coupler configured to couple light out of the second dielectric waveguide in the longitudinal direction.

18. The device according to claim 17, wherein: The third displacement is at least 1 micron greater than the second displacement.

19. The device according to claim 17, wherein: The third displacement is at least 3 microns.

20. A method of manufacturing a device, the method comprising: forming one or more layers of insulating dielectric material on a semiconductor substrate to define a first displacement from the semiconductor substrate, the layers being stacked relative to a lamination axis; forming a light source at the first displacement; forming one or more additional layers of the insulating dielectric material to define a second displacement from the semiconductor substrate; forming a first dielectric waveguide at the second displacement, the first dielectric waveguide overlapping at least a portion of the light source relative to the lamination axis such that light is adiabatically coupled from the light source into the first dielectric waveguide; forming one or more additional layers of the insulating dielectric material to define a third displacement from the semiconductor substrate; and forming a second dielectric waveguide at the third displacement, The second dielectric waveguide overlaps at least a portion of the first dielectric waveguide relative to the lamination axis such that light is coupled from the first dielectric waveguide into the second dielectric waveguide; and The second dielectric waveguide includes an edge coupler configured to couple light out of the second dielectric waveguide in a longitudinal direction perpendicular to the lamination axis.

Images