TW202321748A - Optical element - Google Patents

Abstract

An optical element including a substrate, a first insulating layer, a first optical waveguide layer, a first edge coupler and a first micro-optical element is provided. The first insulating layer is disposed on the substrate. The first optical waveguide layer is disposed on the first insulating layer, and configured to transmit a light beam. The first edge coupler is disposed on the first insulating layer, and coupled to an end of the first optical waveguide layer. The first micro-optical element is disposed on the substrate, and includes a first inclined surface. There is a first groove between the substrate, the first insulating layer, the first optical waveguide layer and the first edge coupler. The first micro-optical element is located within the first groove. The light beam is sequentially transmitted from the first optical waveguide to the first edge coupler, emitted from the first edge coupler, and reflected by the first inclined surface to an optical fiber connector.

Description

Optical element

The present invention relates to an optical element.

Data centers have ever-increasing demands on device bandwidth and speed. In recent years, the optical co-packaged optics (CPO) architecture has risen. When the bandwidth of the network switch (switch) enters the 51.2T generation, the optical fiber packaging density will encounter a bottleneck. Therefore, the photonic chip must introduce wavelength division multiplexing (Wavelength Division Multiplexing, WDM) components to alleviate the issue of fiber density.

The input/output coupler (I/O coupler) of the optical chip used to be a grating coupler, but because of its narrow optical bandwidth, it is not suitable for use in series with wavelength division multiplexing components. On the contrary, the wide optical frequency of the edge coupler is suitable for cascading wavelength division multiplexing components, but its biggest problem is that the measurement efficiency is very low, and it is difficult to introduce into mass production.

The invention provides an optical element, which can be easily measured and is therefore suitable for mass production.

An embodiment of the present invention provides an optical element, which includes a substrate, a first insulating layer, a first optical waveguide layer, a first edge coupler, and a first micro-optical element. The first insulating layer is disposed on the base. The first optical waveguide layer is disposed on the first insulating layer and used for transmitting light beams. The first edge coupler is disposed on the first insulating layer and coupled with one end of the first optical waveguide. The first micro-optical element is disposed on the base and includes a first slope. There is a first groove between the base, the first insulating layer, the first optical waveguide layer and the first edge coupler. The first micro-optical element is located in the first groove. The light beam is sequentially transmitted from the first optical waveguide to the first edge coupler, emerges from the first edge coupler, and is reflected by the first slope to the optical fiber connector.

Based on the above, in an embodiment of the present invention, since the optical element adopts the first edge coupler, it is suitable for connecting wavelength division multiplexing elements in series. Moreover, the optical element is provided with a first micro-optical element, and uses the first micro-optical element to couple the light beam to the optical fiber connector. Therefore, the optical element in the embodiment of the present invention effectively solves the problem of low efficiency of wafer-level measurement, and Contribute to mass production of the overall system.

Fig. 1 is a schematic diagram of an optical element according to a first embodiment of the present invention. Please refer to FIG. 1 , an embodiment of the present invention provides an optical element 10 , which includes a substrate 100 , a first insulating layer 200 , a first optical waveguide layer 300 , a first edge coupler 400 and a first micro-optical element 500 . The first insulating layer 200 is disposed on the substrate 100 . The first optical waveguide layer 300 is disposed on the first insulating layer 200 and used for transmitting the light beam L1. The first edge coupler 400 is disposed on the first insulating layer 200 and coupled to one end of the first optical waveguide 300 . The first micro-optical element 500 is disposed on the substrate 100 and includes a first slope 500S1. There is a first groove G between the substrate 100 , the first insulating layer 200 , the first optical waveguide layer 300 and the first edge coupler 400 . The first micro-optical element 500 is located in the first groove G. As shown in FIG. The light beam L1 is sequentially transmitted from the first optical waveguide 300 to the first edge coupler 400 , emerges from the first edge coupler 400 , and is reflected to the optical fiber connector F by the first slope 500S1 . In an embodiment, the light beam L1 can also be transmitted from the optical fiber connector F to the first slope 500S1 in sequence, reflected by the first slope 500S1 to the first edge coupler 400, and then passed from the first edge coupler 400 to the first Optical waveguide 300 .

In detail, the above-mentioned first groove G is formed by etching back the edges of the first edge coupler 400 , the first optical waveguide layer 300 and the first insulating layer 200 , for example. The first micro-optical element 500, for example, wet-etches semiconductor materials (such as silicon (Si), silicon nitride (SiN), silicon oxynitride (SiON), etc.) After the optical element is packaged in the first groove G with high precision by means of a flip chip bonder or the like. Alternatively, the material of the first micro-optical element 500 is polymer, for example, and the micro-optic element with the first slope 500S1 is formed by 3D printing technology. Then, it is packaged in the first groove G with high precision by means of picking and placing. In another embodiment, the first micro-optical element 500 can also be a mixed structure of silicon, silicon nitride, silicon oxynitride, polymer, metal and other materials, and the refractive index preferably falls within the range of 1.45 to 3.5 , but the present invention is not limited thereto.

In this embodiment, the reflective metal layer 520 is coated on the first slope 500S1 , so that the light beam L1 can be reflected by the first slope 500S1 .

In this embodiment, the first micro-optical element 500 further includes a bottom surface 500S2. The bottom surface 500S2 is connected to the first inclined surface 500S1. The first micro-optical element 500 is connected to the substrate 100 through the bottom surface 500S2. The included angle θ between the first slope 500S1 and the bottom surface 500S2 falls within a range of 30 degrees to 60 degrees.

In this embodiment, there is an air gap A between the first micro-optical element 500 and the first edge coupler 400 . Since the transmission distance of the light beam L1 in the air is not expected to be too long, the distance d between the first micro-optical element 500 and the first edge coupler 400 falls within a range of 0.5 micrometers (μm) to 10 micrometers.

FIG. 2 is an enlarged schematic view of the first micro-optical element in FIG. 1 . Please refer to FIG. 1 and FIG. 2 at the same time. In this embodiment, the first micro-optical element 500 is perpendicular to the transmission direction of the light beam L1 in the first optical waveguide layer 300 and perpendicular to the direction from the substrate 100 to the first optical waveguide layer 300. The length L on falls within the range of 10 micrometers to 1 millimeter (mm). The first micro-optical element 500 is arranged beside the first edge coupler 400, and the function of its slope 500S1 is to reflect the light beam L1, turn the light beam L1 upward, and pass it toward the optical fiber connector F. The geometric structure length of the first micro-optical element 500 L falls within a range of 10 micrometers (μm) to 1 millimeter (mm).

In this embodiment, the width W2 of the first micro-optical element 500 along the transmission direction of the light beam L1 in the first optical waveguide layer 300 falls within a range of 5 micrometers to 125 micrometers.

In this embodiment, the height H of the first micro-optical element 500 along the direction from the substrate 100 to the first optical waveguide layer 300 falls within a range of 1 μm to 62.5 μm.

Based on the above, in an embodiment of the present invention, since the optical element 10 adopts the first edge coupler 400 , it is suitable for connecting wavelength division multiplexing elements in series. Furthermore, the optical element 10 is provided with a first micro-optical element 500 , and the light beam L1 is coupled to the optical fiber connector F by using the first micro-optic element 500 . Therefore, compared to the traditional optical elements using edge couplers that need to cut the wafer to measure the optical wafer, the optical element 10 of the embodiment of the present invention effectively solves the problem of low wafer-level measurement efficiency , and contribute to the mass production of the overall system.

In addition, in addition to forming the bevel 500S1 directly on the optical element 10 through the etching process, the fabrication process of the micro-optical element 500 also adopts a packaging method (such as flip-chip bonder) to integrate the micro-optical element 500 on the side of the edge coupler 400 to form The 45-degree reflective slope 500S1 has several advantages: (1) the geometric structure of the micro-optical element 500 has a large degree of elasticity (as shown in Figures 3, 4, 5A, 5B, 6, and 7); (2) it does not The reflective slope 500S1 needs to be wet-etched with acid and alkali solutions, and the manufacturing process is relatively simple; (3) The bonding temperature of the micro-optical element 500 and the bottom surface 500S2 is low (for example, PDMS bonding 80~100 degrees C), which will not affect other previous processes. Completed components (Note: The thermal budget of the general CMOS back-end process is about 400 degrees C or less).

Fig. 3 is a schematic diagram of an optical element according to a second embodiment of the present invention. Please refer to FIG. 3 , the optical element 10A is substantially the same as the optical element 10 in FIG. 1 , the main differences are as follows. In this embodiment, the first micro-optical element 500A further includes a second slope 500S3. The second slope 500S3 is opposite to the first slope 500S1 and faces the substrate 100 . Wherein, the second slope 500S3 helps to align with the first groove G during the pick-and-place process of the first micro-optical element 500A, so that the first micro-optic element 500A slides into the first groove G automatically.

In this embodiment, in the direction from the first optical waveguide layer 300 to the substrate 100, the bottom position P1 of the first slope 500S1 is lower than the bottom P2 of the first optical waveguide layer 300, which helps to lift the light beam L1 from the first The optical coupling efficiency of the edge coupler 400 to the first slope 500S1.

In addition, in this embodiment, the reflective metal layer 520 is coated on the first slope 500S1 , so that the light beam L1 can be reflected by the first slope 500S1 . The rest of the advantages of the optical element 10A are similar to those of the optical element 10 and will not be repeated here.

Fig. 4 is a schematic diagram of an optical element according to a third embodiment of the present invention. Please refer to FIG. 4 , the optical element 10B is substantially the same as the optical element 10A in FIG. 3 , the main differences are as follows. In this embodiment, the optical element 10B further includes a cantilever structure 600 . The cantilever structure 600 is connected to the first micro-optical element 500A. In another embodiment, the cantilever structure 600 can be integrally formed with the first micro-optical element 500A. Wherein, the cantilever structure 600 is used to lean on the first edge coupler 400, so that the bottom of the first inclined surface 500S1 is lower than the bottom of the first optical waveguide layer 300, so as to elevate the light beam L1 from the first edge coupler 400 to the second Optical coupling efficiency of a bevel 500S1. For example, when the first groove G is too deep after the etching process, the setting height of the first slope 500S1 will be too low, which will affect the light coupling efficiency of the optical element. Therefore, providing the cantilever structure 600 can avoid the aforementioned problem that the first groove G is too deep.

In addition, in this embodiment, the reflective metal layer 520 is coated on the first slope 500S1 , so that the light beam L1 can be reflected by the first slope 500S1 . The remaining advantages of the optical element 10B are similar to those of the optical element 10A, and will not be repeated here.

Fig. 5A is a schematic diagram of an optical element according to a fourth embodiment of the present invention. FIG. 5B is an enlarged schematic view of the lens in FIG. 5A . Please refer to FIG. 5A and FIG. 5B , the optical element 10C is substantially the same as the optical element 10B in FIG. 4 , and the main differences are as follows. In this embodiment, the optical element 10C further includes a lens 700 . The lens 700 is disposed on the first slope 500S1 , disposed on the transmission path of the light beam L1 , and used for collimating the light beam L1 . In another embodiment, the lens 700 can be integrally formed with the cantilever structure 600 , or the lens 700 can be integrally formed with the cantilever structure 600 and the first micro-optical element 500A. Wherein, the light beam L1 emerges from the first edge coupler 400 and is reflected by the first slope 500S1 to the lens 700 , passes through the lens 700 and then is transmitted to the optical fiber connector F. Alternatively, the light beam L1 is sequentially transmitted from the optical fiber connector F to the lens 700 , passes through the lens 700 , is transmitted to the first slope 500S1 , and is reflected by the first slope 500S1 to the first edge coupler 400 .

In this embodiment, the diameter D of the lens 700 preferably corresponds to the diameter of the fiber optic connector F, for example, the diameter of a single-mode fiber optic connector and a multi-mode fiber optic connector. between sizes. In one embodiment, the diameter D of the lens 700 falls within a range of 8 microns to 62.5 microns.

In this embodiment, the distance S between the overlapping area of the lens 700 and the first fringe coupler 400 falls within a range of 0 μm to D/2. The thickness t of the lens 700 falls within a range of 50 μm to 1 mm. Since the optical element 10C is provided with the lens 700, it can improve the light coupling efficiency.

In addition, in this embodiment, the reflective metal layer 520 is coated on the first slope 500S1 , so that the light beam L1 can be reflected by the first slope 500S1 . The remaining advantages of the optical element 10C are similar to those of the optical element 10B, and will not be repeated here.

Fig. 6 is a schematic diagram of an optical element according to a fifth embodiment of the present invention. Please refer to FIG. 6 , the optical element 10D is substantially the same as the optical element 10A in FIG. 3 , the main differences are as follows. In this embodiment, the first slope 500S1 in the first micro-optical element 500D is directly connected to the second slope 500S3 .

In addition, in this embodiment, the reflective metal layer 520 is coated on the first slope 500S1 , so that the light beam L1 can be reflected by the first slope 500S1 . The remaining advantages of the optical element 10D are similar to those of the optical element 10A, and will not be repeated here.

Fig. 7 is a schematic diagram of an optical element according to a sixth embodiment of the present invention. Please refer to FIG. 7 , the optical element 10E is substantially the same as the optical element 10 in FIG. 1 , the main differences are as follows. In this embodiment, the first micro-optical element 500E further includes a vertical surface 500S4. Two ends of the vertical surface 500S4 are connected to the first inclined surface 500S1 and the bottom surface 500S3 respectively.

In addition, in this embodiment, the reflective metal layer 520 is coated on the first slope 500S1 , so that the light beam L1 can be reflected by the first slope 500S1 . The rest of the advantages of the optical element 10E are similar to those of the optical element 10 and will not be repeated here.

Fig. 8 is a schematic diagram of an optical element according to a seventh embodiment of the present invention. Please refer to FIG. 8 , the optical element 10F is substantially the same as the optical element 10 in FIG. 1 , the main differences are as follows. In this embodiment, the optical element 10F further includes at least one second insulating layer 200', at least one second optical waveguide layer (not shown in the figure), at least one second edge coupler 400' and at least one second micro Optical element 500'. The second insulating layer 200' is disposed on the substrate 100. Similar to the first optical waveguide layer 300 of FIG. 1, the second optical waveguide layer is disposed on the second insulating layer 200'. The second edge coupler 400' is disposed on the second insulating layer 200', and is coupled to one end of the second optical waveguide (in a direction perpendicular to the paper plane of FIG. 6 ). The second micro-optical element 500' is disposed on the substrate 100, and the second micro-optic element 500' is located beside the first micro-optic element 500. Each second micro-optical element 500' includes a third slope 500S1'. There is at least one second groove G' between the substrate 100, the second insulating layer 200', the second optical waveguide layer and the second edge coupler 400', and the second groove G' is located beside the first groove G. The second micro-optical element 500' is located in the second groove G'.

Wherein, the first micro-optical element 500 and the second micro-optical elements 500' respectively correspond to an optical fiber connector on the optical path. That is to say, the first micro-optical element 500 and the second micro-optical element 500' can be integrated into the optical element 10F by single-chip transfer or mass transfer, thereby improving the overall data throughput of wafer-level measurement.

In addition, in this embodiment, the reflective metal layer 520 is coated on the first slope 500S1 and the third slope 500S1', so that the light beam can be reflected by the first slope 500S1 or the third slope 500S1'. The rest of the advantages of the optical element 10F are similar to those of the optical element 10 and will not be repeated here.

To sum up, in an embodiment of the present invention, since the optical element adopts the first edge coupler, it is suitable for connecting wavelength division multiplexing elements in series. Furthermore, the optical element is provided with a first micro-optical element, and uses the first micro-optic element to couple the light beam to the fiber optic connector. Therefore, compared with the traditional optical elements using edge couplers that need to cut the wafer to measure the optical wafer, the optical element of the embodiment of the present invention effectively solves the problem of low measurement efficiency at the wafer level, and contributes to the overall mass production of the system.

10, 10A, 10B, 10C, 10D, 10E, 10F: Optical components 100: base 200: first insulating layer 200': second insulating layer 300: the first optical waveguide layer 400: First edge coupler 400': Second edge coupler 500, 500A, 500D, 500E: the first micro-optical element 500': second micro optics 500S1: first bevel 500S1’: the third bevel 500S2: Bottom 500S3: second bevel 500S4: vertical plane 520: metal layer 600: cantilever structure 700: lens A: air gap d, S: distance D: diameter t: thickness F: fiber optic connector G: first groove G': second groove H: height L: Length L1: light beam P1: bottom position P2: bottom W2: width θ: included angle

Fig. 1 is a schematic diagram of an optical element according to a first embodiment of the present invention. FIG. 2 is an enlarged schematic view of the first micro-optical element in FIG. 1 . Fig. 3 is a schematic diagram of an optical element according to a second embodiment of the present invention. Fig. 4 is a schematic diagram of an optical element according to a third embodiment of the present invention. Fig. 5A is a schematic diagram of an optical element according to a fourth embodiment of the present invention. FIG. 5B is an enlarged schematic view of the lens in FIG. 5A . Fig. 6 is a schematic diagram of an optical element according to a fifth embodiment of the present invention. Fig. 7 is a schematic diagram of an optical element according to a sixth embodiment of the present invention. Fig. 8 is a schematic diagram of an optical element according to a seventh embodiment of the present invention.

10: Optical components

100: base

200: first insulating layer

300: the first optical waveguide layer

400: First edge coupler

500: The first micro-optical element

500S1: first bevel

500S2: Bottom

520: metal layer

A: air gap

d: distance

F: fiber optic connector

G: first groove

L1: light beam

θ: included angle

Claims (10)

An optical element comprising: a base; a first insulating layer disposed on the base; a first optical waveguide layer, disposed on the first insulating layer, and used to transmit a light beam; a first edge coupler disposed on the first insulating layer and coupled to one end of the first optical waveguide; and A first micro-optical element is disposed on the substrate and includes a first slope, wherein there is a first groove between the substrate, the first insulating layer, the first optical waveguide layer and the first edge coupler, and the first micro-optical element is located in the first groove, The light beam is sequentially transmitted from the first optical waveguide to the first edge coupler, emerges from the first edge coupler, and is reflected by the first slope to a fiber optic connector. The optical element as claimed in claim 1, wherein the first slope is coated with a reflective metal layer. The optical element as claimed in claim 1, wherein the first micro-optical element further includes a bottom surface, the bottom surface is connected to the first inclined surface, and the first micro-optic element is connected to the substrate through the bottom surface, Wherein the included angle between the first slope and the bottom surface is in the range of 30 degrees to 60 degrees. The optical element as claimed in claim 1, wherein there is an air gap between the first micro-optical element and the first edge coupler. The optical element as claimed in claim 1, wherein the first micro-optical element further comprises a second slope, the second slope is opposite to the first slope and faces the substrate, Wherein in the direction from the first optical waveguide layer to the base, the bottom of the first slope is lower than the bottom of the first optical waveguide layer. The optical element as claimed in claim 5, wherein the first slope is directly connected to the second slope. The optical element as claimed in claim 3, wherein the first micro-optical element further includes a vertical surface, and two ends of the vertical surface are respectively connected to the first inclined surface and the bottom surface. The optical element as described in Claim 1, further comprising: a lens, arranged on the first slope, arranged on the transmission path of the light beam, and used to collimate the light beam, Wherein the light beam emerges from the first edge coupler and is reflected by the first slope to the lens. The optical element as claimed in claim 7, wherein the distance between the lens and the overlapping region of the first edge coupler falls within the range of 0 microns to D/2, wherein D is the diameter of the lens. The optical element as described in Claim 1, further comprising: at least one second insulating layer disposed on the substrate; at least one second optical waveguide layer disposed on the at least one second insulating layer; at least one second edge coupler disposed on the at least one second insulating layer and coupled to one end of the at least one second optical waveguide; and At least one second micro-optical element is disposed on the substrate, each second micro-optic element includes a third slope, Wherein there is at least one second groove between the substrate, the at least one second insulating layer, the at least one second optical waveguide layer and the at least one second edge coupler, and the at least one second micro-optical element is located at the at least one a second groove.

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