Optical wavelength division multiplexing device and manufacturing method thereof

Abstract

The invention relates to the technical field of optical devices, and provides an optical wavelength division multiplexing device and a manufacturing method thereof.The optical wavelength division multiplexing device comprises an optical filter and an optical waveguide sample wafer with a penetrating microgroove formed in a Y-shaped connector, and the optical filter is inserted into the microgroove; the width of the optical waveguide sample wafer at the corner and the Y-shaped joint is larger than the width of the rest part, a connection section adopts a mode that the width is uniformly and gradually changed, and a waveguide coupling end face adopts a wedge-shaped spot size converter. The high coupling efficiency with free space light or optical fibers and the like is achieved, lower optical waveguide transmission loss is achieved, and application to current mainstream material platforms such as silicon substrates, lithium niobate, silicon nitride and polymers is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of optical devices, and in particular to an optical wavelength division multiplexing device and a manufacturing method thereof. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] With the popularization of the Internet and the continuous improvement of demand, the user groups have increasingly diverse demands for the network. At the same time, smart homes, ultra-high-definition 4K / 8K live video broadcasts, and VR game online experiences have placed higher requirements on network access speeds. With the launch of the third-generation access network standards by the two major international organizations IEEE and ITU in 2016, the curtain has been raised on the development of access networks.

[0004] At the same time, in addition to considering performance, the upgrade of the access network must also take into account breaking through bottlenecks, such as cost control, compatibility with existing optical fiber facilities and achieving low insertion loss, high isolation and multi-channel integration in a narrow wavelength range.

[0005] At present, the waveguide width of optical wavelength division multiplexing devices mostly adopts a fixed width, resulting in high optical waveguide transmission loss; and the coupling efficiency with free space light or optical fiber is low; in addition, the filter structure is mostly assembled from a substrate and a filter film, and the total thickness of the two is only 20um. If the two parts are superimposed and glued together, the thickness of the single part is bound to be much lower than 20um, and the actual cutting of the material is difficult to ensure the required size of the complete piece. Summary of the invention

[0006] In order to address the deficiencies of the prior art, the present invention provides an optical wavelength division multiplexing device and a method for manufacturing the same. A tapered pattern converter is used at the waveguide coupling end face to achieve higher coupling efficiency with free-space light or optical fiber, and a gradient width is used for the waveguide width to achieve lower optical waveguide transmission loss. The device is also easy to apply to mainstream silicon-based, lithium niobate, silicon nitride, polymer and other material platforms.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A first aspect of the present invention provides an optical wavelength division multiplexing device.

[0009] A wavelength division multiplexing device, characterized in that it comprises a filter and a planar optical waveguide, wherein the planar optical waveguide is provided with a Y-shaped joint, the Y-shaped joint is provided with a microgroove, the filter is fixed in the microgroove, the filter is in the plane of the optical waveguide, and the filter is fixed in the microgroove.

[0010] Furthermore, the planar optical waveguide includes at least two first curved waveguides, one second curved waveguide and two straight waveguides, the head end of the first curved waveguide is connected to the end of the straight waveguide, there is an angle between the first curved waveguide and the straight waveguide, the ends of the two first curved waveguides are connected to the head section of the second curved waveguide, and the two first curved waveguides are connected to the second curved waveguide to form a Y-shaped joint.

[0011] Furthermore, an angle is formed between the second curved waveguide and the straight waveguide.

[0012] Furthermore, the optical filter includes optical glass and a coating layer, and the coating layer is arranged on the surface of the optical glass.

[0013] Furthermore, the thickness of the optical glass is in the range of 18 to 20 μm.

[0014] Furthermore, the width of the Y-shaped connector is in the range of 6 to 13 μm; the Y-shaped connector includes a connecting section and a bifurcated section, and the width of the connecting section is greater than the width of the bifurcated section.

[0015] Furthermore, the width of the microgroove is 25 μm.

[0016] Furthermore, an angle is formed between the microgroove and the transmission direction of the optical waveguide.

[0017] Furthermore, the waveguide coupling end face of the planar optical waveguide adopts a wedge-shaped pattern spot converter.

[0018] A second aspect of the present invention provides a method for manufacturing an optical wavelength division multiplexing device, comprising the following steps:

[0019] Processing and cutting microgrooves on the optical waveguide sample, so that the microgrooves are located at the Y-shaped joint and are perpendicular to the optical waveguide plane;

[0020] Based on the target wavelength, an optical glass sheet is selected, and after coating the surface of the optical glass sheet, the optical glass sheet is cut into the required size to obtain a filter;

[0021] The filter is fixed in the microgroove to obtain an optical wavelength division multiplexing device as described in claims 1-8.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The optical wavelength division multiplexing device described in the present invention adopts a pattern spot converter with a Taper structure at the waveguide coupling end face to achieve higher coupling efficiency with free space light or optical fiber, and the waveguide width adopts a gradient width to achieve lower optical waveguide transmission loss, and is easy to be applied on the current mainstream silicon-based, lithium niobate, silicon nitride and polymer material platforms.

[0024] The optical wavelength division multiplexing device described in the present invention realizes light filtering by directly coating a film on a substrate, thereby avoiding the bottleneck of ultra-thin filter cutting, reducing assembly procedures and improving yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 This is a structural diagram of an optical wavelength division multiplexing device according to Embodiment 1 of the present invention;

[0027] Figure 2 Schematic diagram of the SSC width variation of the waveguide end face in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0032] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0033] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0034] Example 1

[0035] Embodiment 1 of the present invention provides an optical wavelength division multiplexing device.

[0036] An optical wavelength division multiplexing device is an optical device for realizing wavelength division multiplexing, such as Figure 1 As shown, it includes a planar optical waveguide and a filter with a TFF-WDM (Thin Film Filter) structure.

[0037] The planar optical waveguide is provided with a Y-junction. Specifically, the planar optical waveguide includes at least two first curved waveguides, one second curved waveguide and two straight waveguides, the head end of the first curved waveguide is connected to the end of the straight waveguide, there is an angle between the first curved waveguide and the straight waveguide, the ends of the two first curved waveguides are connected to the head section of the second curved waveguide, and the two first curved waveguides are connected to the second curved waveguide to form a Y-junction.

[0038] A microgroove is provided on the Y-shaped joint, and the filter is fixed in the microgroove.

[0039] In this embodiment, the microgroove is perpendicular to the optical waveguide plane, and the width of the microgroove may be 25 μm.

[0040] Among them, the planar optical waveguide is a PLC-WDM optical waveguide sample, and the material is silica glass.

[0041] The angle between the microgroove and the second curved waveguide and the angle between the first curved waveguide and the straight waveguide are both determined by the refractive index of the planar optical waveguide to air. In this embodiment, the angle can be 8°.

[0042] like Figure 2 As shown, the width of the Y-shaped joint of the planar optical waveguide gradually changes, and the parameter range is between 6 and 13μm, so as to achieve lower optical waveguide transmission loss and facilitate application on the current mainstream silicon-based, lithium niobate, silicon nitride and polymer material platforms.

[0043] Specifically, the width of the head end of the straight waveguide, the head section and the end of the first curved waveguide, the head section and the end of the second curved waveguide, and the width of the Y-shaped joint are the largest. That is, the width of the straight waveguide gradually narrows from the head end to the end, and the width of the first curved waveguide and the second curved waveguide gradually narrows from the two ends to the middle. The width of the Y-shaped joint changes evenly and gradually, and the Y-shaped joint includes a connecting section and a forked section. The width of the connecting section is greater than the width of the forked section. The connecting section is used to connect the second curved waveguide, and the two forked sections are used to connect the two first curved waveguides respectively.

[0044] The waveguide coupling end face of the planar optical waveguide adopts a tapered SSC (spot size converter) to achieve higher coupling efficiency with free space light or optical fiber. Its width varies as follows: Figure 2 shown.

[0045] Among them, the filter is obtained by coating the surface of ultra-thin optical glass (about 18-20um thick) and then cutting it. Light filtering is achieved by directly coating on the 18-20um substrate, avoiding the bottleneck of ultra-thin filter cutting, while reducing the assembly process and improving the yield.

[0046] Among them, the parameters of the PLC optical waveguide structure are as follows: the refractive index of the waveguide core is 1.466, the refractive index of the cladding is 1.455, the refractive index difference is 0.75%, the waveguide size is 6*6μm, and considering the existence of material bending loss, the waveguide bending radius is selected to be 5000μm.

[0047] The present embodiment provides an optical wavelength division multiplexing device, which realizes multi-wavelength integrated combination and can be miniaturized. While realizing multi-wavelength integration, it also has the characteristics of high isolation and low insertion loss of TFF-WDM spatial optical filters. The structure is simple to assemble and has high reliability.

[0048] Example 2

[0049] Embodiment 2 of the present invention provides a method for manufacturing an optical wavelength division multiplexing device as in Embodiment 1, comprising the following steps:

[0050] Step 1: machining and cutting microgrooves on a planar optical waveguide, so that the microgrooves are located at the Y-shaped joint and are perpendicular to the optical waveguide plane.

[0051] According to the simulation design of planar optical waveguide, the PLC-WDM optical waveguide structure of the required wavelength of optical wavelength division multiplexing is designed, and the PLC-WDM optical waveguide sample is produced. In the direction perpendicular to the optical waveguide, a cutting machine is used to process a micro groove of about 25μm at the position of the Y-shaped joint in the middle section perpendicular to the plane of the optical waveguide sample. The micro groove penetrates the entire thickness of the PLC sample, and the micro groove forms an angle of 8° with the transmission direction of the optical waveguide plane.

[0052] Step 2: Based on the target wavelength, select an optical glass sheet, coat the surface of the optical glass sheet, and cut it into the required size to obtain a filter.

[0053] Specifically, an optical coating method is adopted, optical glass is selected according to the target wavelength, and coating is performed on the optical glass. After the coating is completed, the target size is cut to form the required filter.

[0054] Step 3: Fix the filter in the micro-groove to obtain an optical wavelength division multiplexing device.

[0055] Insert the filter into the microgroove of the planar optical waveguide, and fix the filter and the planar optical waveguide with optical glue to form a whole. At this point, the manufacturing process is completed, and a wavelength division multiplexing device with low insertion loss, high isolation and multi-channel integration is realized.

[0056] The manufacturing method of a wavelength division multiplexing device provided in this embodiment can meet the requirements of miniaturized packaging and simple assembly. The assembled wavelength division multiplexing device has high reliability, is compatible with multi-wavelength integration, and has the characteristics of high isolation and low insertion loss of TFF-WDM spatial optical filters.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An optical wavelength division multiplexing device, characterized in that: The optical filter comprises an optical filter and a planar optical waveguide. The planar optical waveguide is provided with a Y-shaped joint, the Y-shaped joint is provided with a microgroove, the optical filter is fixed in the microgroove, the optical filter is on the plane of the optical waveguide, and the optical filter is fixed in the microgroove.

2. An optical wavelength division multiplexing device as claimed in claim 1, characterized in that: The planar optical waveguide includes at least two first curved waveguides, one second curved waveguide and two straight waveguides, the head end of the first curved waveguide is connected to the end of the straight waveguide, there is an angle between the first curved waveguide and the straight waveguide, the ends of the two first curved waveguides are connected to the head section of the second curved waveguide, and the two first curved waveguides are connected to the second curved waveguide to form a Y-shaped joint.

3. An optical wavelength division multiplexing device as claimed in claim 2, characterized in that: An included angle is formed between the second curved waveguide and the straight waveguide.

4. An optical wavelength division multiplexing device as claimed in claim 1, characterized in that: The optical filter comprises optical glass and a coating layer, wherein the coating layer is arranged on the surface of the optical glass.

5. An optical wavelength division multiplexing device as claimed in claim 4, characterized in that: The thickness of the optical glass is in the range of 18 to 20 μm.

6. An optical wavelength division multiplexing device as claimed in claim 1, characterized in that The width of the Y-shaped connector is in the range of 6 to 13 μm; the Y-shaped connector comprises a connecting section and a bifurcated section, and the width of the connecting section is greater than the width of the bifurcated section.

7. An optical wavelength division multiplexing device as claimed in claim 1, characterized in that: The width of the microgroove is 25 μm.

8. An optical wavelength division multiplexing device as claimed in claim 1, characterized in that: An angle is formed between the microgroove and the transmission direction of the optical waveguide.

9. An optical wavelength division multiplexing device as claimed in claim 1, characterized in that: The waveguide coupling end face of the planar optical waveguide adopts a mode spot converter with a wedge-shaped structure.

10. A method for manufacturing an optical wavelength division multiplexing device, characterized in that: The steps include: Processing and cutting microgrooves on the optical waveguide sample, so that the microgrooves are located at the Y-shaped joint and are perpendicular to the optical waveguide plane; Based on the target wavelength, an optical glass sheet is selected, and after coating the surface of the optical glass sheet, the optical glass sheet is cut into the required size to obtain a filter; The filter is fixed in the microgroove to obtain an optical wavelength division multiplexing device as described in claims 1-8.

Images