Wavelength division apparatus capable of improving filter alignment accuracy and method for manufacturing a wavelength division apparatus

Abstract

This invention provides a method for easily manufacturing a wavelength division device having multiple channels. [Solution] The wavelength division device includes a substrate having one or more grooves, a plurality of filter bars disposed in one or more of the grooves of the substrate, and a prism disposed on the substrate. Each of the filter bars corresponds to an optical filtering wavelength. The prism is used to cover the plurality of filter bars. The surface of the substrate is etched to form one or more of the grooves. After the plurality of filter bars are coated, the plurality of filter bars are joined in one or more of the grooves of the substrate. The resin disposed on the substrate is imprinted by a processing mold to form the prism.

Description

Technical Field

[0001] The present invention relates to a wavelength division device and a method for manufacturing the wavelength division device, and more specifically, to a wavelength division device and a method for manufacturing the wavelength division device capable of improving filter alignment accuracy and reducing a bonding alignment process.

Background Art

[0005] Another embodiment of the present invention discloses a method for manufacturing a wavelength division device. The method for manufacturing a wavelength division device includes the steps of etching the surface of a substrate to form one or more grooves, coating a plurality of filter bars, joining the plurality of filter bars in one or more grooves in the substrate after coating them, and imprinting a resin placed on the substrate using a processing mold to form a prism. Each of the filter bars corresponds to an optical filtering wavelength. The prism is placed on the substrate and configured to cover the plurality of filter bars.

[0006] These and other objects of the present invention will become undoubtedly apparent to those skilled in the art after reading the following detailed description of preferred embodiments shown in various figures and drawings. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows the structure of a wavelength division device according to one embodiment of the present invention.

[0008] [Figure 2] This figure shows the first step in manufacturing the wavelength division device shown in Figure 1.

[0009] [Figure 3] This figure shows the second stage in the manufacturing of the wavelength division device shown in Figure 1.

[0010] [Figure 4] This is a diagram showing the third stage of manufacturing the wavelength division device of FIG. 1.

[0011] [Figure 5] This is a diagram showing the fourth stage of manufacturing the wavelength division device of FIG. 1.

[0012] [Figure 6] This is a diagram showing the fifth stage of manufacturing the wavelength division device of FIG. 1.

[0013] [Figure 7] This is a diagram showing the sixth stage of manufacturing the wavelength division device of FIG. 1.

[0014] [Figure 8] This is a diagram showing the optical path for executing the multiplexing mechanism by the wavelength division device of FIG. 1.

[0015] [Figure 9] This is a diagram showing the optical path for executing the demultiplexing mechanism by the wavelength division device of FIG. 1.

[0016] [Figure 10] This shows the coating technology of the substrate of the wavelength division device of FIG. 1 when the multiplexing mechanism is executed.

[0017] [Figure 11] This shows the coating technology of the substrate of the wavelength division device of FIG. 1 when the demultiplexing mechanism is executed.

[0018] [Figure 12] This is a flowchart for manufacturing the wavelength division device of FIG. 1.

Embodiments for Carrying Out the Invention

[0019] Figure 1 shows the structure of a wavelength division device 100 according to one embodiment of the present invention. The wavelength division device 100 can be a wavelength division multiplexer or a wavelength division demultiplexer, thereby enabling the simultaneous transmission of multiple optical signals having different wavelengths over a single optical fiber. The wavelength division device 100 includes a substrate 10, a plurality of filter bars FB1 to FB4, and a prism 11. The substrate 10 can be a base material to which other components are attached. In this embodiment, the substrate 10 can be a glass wafer having a plurality of etched grooves. The plurality of filter bars FB1 to FB4 are arranged in one or more grooves of the substrate 10. Each of the filter bars FB1 to FB4 corresponds to an optical filtering wavelength. Here, the filter bar can selectively pass only a specific wavelength of light while blocking or reflecting other wavelengths. The specific wavelength can be selected from the O-band range (1260 nm to 1360 nm). The prism 11 is placed on the substrate 10 and is configured to cover the plurality of filter bars FB1 to FB4. In this embodiment, the prism 11 can be a triangular resin piece or other transparent material that refracts (or reflects) light. In the wavelength division device 100, the surface of the substrate 10 is etched to form one or more grooves. After the multiple filter bars FB1 to FB4 are coated, the multiple filter bars FB1 to FB4 can be joined in one or more grooves of the substrate 10. Furthermore, the resin placed on the substrate 10 can be imprinted by a processing mold to form the prism 10. Details of the manufacturing of the wavelength division device 100 are described below.

[0020] Figure 2 shows the first step in manufacturing the wavelength division apparatus 100. As previously mentioned, the substrate 10 has one or more grooves 10a. In one embodiment, one or more grooves 10a can be formed on a glass wafer substrate by using a “dry etching” technique. The substrate 10 can be a glass wafer. For example, a mask can be applied to the surface of the glass wafer. This mask defines the pattern of grooves 10a to be etched. The mask material is resistant to the etching solution and protects the area beneath while allowing the exposed area to be etched. Next, the glass wafer is placed in a dry etching chamber. Plasma is generated in the chamber. Here, the plasma is a highly ionized gas containing ions, electrons, and neutral atoms. The ions in the plasma collide with the exposed area of ​​the glass wafer, physically or chemically removing the material and forming one or more grooves 10a. After etching is complete, the mask can be removed using a suitable solvent or stripping process. In the wavelength division apparatus 100, one or more grooves 10a have substantially the same depth and substantially the same width. For example, the groove depth D can be 10 micrometers. The groove width W can be 125 micrometers. In Figure 2, the substrate 10 can be a glass substrate having a precise array of grooves 10a. These grooves 10a can provide designated positions for arranging filter bars FB1 to FB4, ensuring precise alignment and spacing within the wavelength division device 100.

[0021] FIG. 3 shows the second stage of manufacturing the wavelength division device 100. Here, each of the filter bars FB1 to FB4 is individually coated with a specific "glass coating liquid material". This allows for the application of an individual coating process to each bar, enabling precise control over the optical properties of each filter. The main function of the coating is to create wavelength-selective filters. By varying the composition of the coating material, each filter bar can be adjusted to transmit a specific wavelength band while reflecting or absorbing other filter bars. Next, an adhesive material having a refractive index matching that of glass can be used to bond the plurality of filter bars FB1 to FB4 within one or more grooves 10a of the substrate 10. For example, in FIG. 2, a dedicated automated PnP (pick and place) machine (such as nozzle 12) is used. The PnP machine can accurately identify and locate individual filter bars from a source such as a glass wafer. This ensures the selection of the correct filter bar for each groove 10a. The PnP machine can accurately align a filter bar (such as filter bar FB3) with the corresponding groove 10a on the substrate 10. Once aligned, the filter bars FB1 to FB4 can be bonded to the substrate 10 within the grooves 10a. For example, a small amount of adhesive can be applied to the bottom of the groove 10a or the filter bars FB1 to FB4 before placement. The adhesive can be an ultraviolet (UV) curable epoxy or a thermally conductive material to ensure secure attachment and heat dissipation. The grooves 10a can be used to position the filter bars FB1 to FB4 bonded onto the substrate 10, ensuring the accurate placement and secure attachment of the filter bars, which are essential for achieving the desired optical filtering characteristics and overall device functionality.

[0022] Figure 4 shows the third stage of manufacturing the wavelength division device 100. After bonding the multiple filter bars FB1 to FB4 in one or more grooves 10a of the substrate 10, the substrate 10 is treated by either a thermosetting process to heat the adhesive material between the multiple filter bars FB1 to FB4 and the one or more grooves 10a, or by a UV light curing process to convert the adhesive material from a liquid state to a cured state. After the thermosetting or UV light curing process is completed, in Figure 4, the resin 20 is placed on the substrate 10 and configured to cover the multiple filter bars FB1 to FB4. In this embodiment, the resin 20 should be highly transparent in order to allow light to pass through with minimal loss or distortion. Furthermore, the resin 20 needs to have a viscosity suitable for the imprint process. The resin 20 should be fluid enough to flow into the mold cavity and conform to the prism shape, but should not be so fluid that it spreads uncontrollably. The resin 20 should be curable. The resin 20 can transition from a liquid to a solid state. This can be achieved by UV curing, thermal curing, or other methods. The curing process should yield a stable, solid prism structure. In this embodiment, the resin 20 may be an epoxy resin.

[0023] Figure 5 shows the fourth stage of manufacturing the wavelength division device 100. Figure 6 shows the fifth stage of manufacturing the wavelength division device 100. In Figure 5, a processing mold 30 having a predetermined pattern 30a corresponding to the desired prism shape can be selected. Specifically, the processing mold 30 has a cavity having the inverse shape of the prism 11. Next, the processing mold 30 is carefully positioned on the resin 20 (in liquid state) on the substrate 10 to ensure proper alignment to achieve the desired orientation and position of the prism. After positioning the processing mold 30, the processing mold 30 presses the resin 20 with a controlled force for a certain duration to form the prism 11. This force should be sufficient to ensure that the resin 20 completely fills the cavity of the processing mold and conforms to the shape of the prism. In Figure 6, the controlled force (or, for example, pressure) is maintained for a duration that allows the resin 20 to completely take the shape of the processing mold 30. This duration depends on the properties of the resin and the desired prism dimensions. In this embodiment, if the resin 20 requires a curing process, the assembly in Figure 6 can be subjected to an appropriate curing method, such as UV curing, thermal curing, or other curing methods. In Figure 6, it is important to ensure complete curing of the resin 20 in order to achieve the desired mechanical and optical properties of the prism 11.

[0024] Figure 7 shows the sixth step in manufacturing the wavelength division device 100. After imprinting and curing the resin 20, the processing mold 30 is removed from the substrate 10. In one embodiment, a release agent can be applied to the processing mold 30 before the imprinting step to facilitate demolding. The release agent can form a thin layer between the processing mold 30 and the resin 20, reducing adhesion and allowing for easier separation. Furthermore, the demolding step may include applying a controlled force to separate the processing mold 30 from the curing resin 20. The controlled force should be sufficient to overcome the adhesion between the processing mold 30 and the resin 20, but should not be so high as to damage the prism 11 or the substrate 10. After removing the processing mold 30 from the substrate 10, the substrate 10 is cut to adjust the size of the wavelength division device 100. Finally, the wavelength division device 100 is fully manufactured.

[0025] Figure 8 shows the optical path through which the wavelength division device 100 performs the multiplexing mechanism. The wavelength division device 100 can be a wavelength division multiplexer. In other words, the wavelength division device 100 can transmit multiple optical signals simultaneously through a single optical fiber by using laser light of different wavelengths. Each optical signal is carried at its own specific wavelength. A wavelength division multiplexer allows multiple optical signals to be coupled and transmitted without interfering with each other. In Figure 8, the prism 11 of the wavelength division device 100 includes a first surface P1, a second surface P2, and a third surface P3. The first surface P1 is configured to receive multiple optical signals L11-L14 having multiple optical wavelengths. The second surface P2 is positioned adjacent to the first surface P1 and is configured to reflect multiple optical signals to generate multiple reflected optical signals. For example, optical signals L11-L14 can each be reflected by the second surface P2 to generate reflected optical signals R11-R14. The third surface P3 is positioned adjacent to the first surface P1 and the second surface P2 and is configured to receive multiple reflected light signals R11 to R14. These multiple reflected light signals R11 to R14 are received by multiple filter bars FB1 to FB4 through the third surface P3 of the prism 11. Furthermore, the multiple reflected light signals R11 to R14 are multiplexed by the substrate 10 to generate a combined optical signal. Details are described below. Optical signal F11 is generated by filtering the reflected light signal R11. When the reflected light signal R11 passes through the filter bar FB4, optical signal F11 is the reflected light signal R11. Next, optical signal F11 is reflected by the substrate 10 and combined with the reflected light signal R12 when the reflected light signal R12 passes through the filter bar FB3 to generate optical signal F12. Next, the optical signal F12 is reflected by the substrate 10 and combined with the reflected optical signal R13 as it passes through the filter bar FB2 to generate the optical signal F13. Then, the optical signal F13 is reflected by the substrate 10 and combined with the reflected optical signal R14 as it passes through the filter bar FB1 to generate the optical signal L_com1. This allows the optical signal L_com1 to be output from the substrate 10 via the lens 40.In Figure 8, multiple optical signals L11 to L14 can be multiplexed to generate the optical signal L_com1 via the wavelength division device 100, so the optical signal L_com1 can be considered as a composite optical signal carried by a single optical fiber. Figure 9 shows the optical path through which the wavelength division device 100 performs the demultiplexing mechanism. The wavelength division device 100 can be a wavelength division demultiplexer. In other words, the wavelength division device 100 can acquire a composite optical signal containing optical signals of multiple wavelengths and separate them into individual wavelengths. It is essentially the reverse process of wavelength division multiplexing. In Figure 9, the composite optical signal L_com2 can be demultiplexed and filtered by the substrate 10 and multiple filter bars FB1 to FB4 to generate multiple filtered optical signals R21 to R24. Details are described below. After the composite optical signal L_com2 is input to the substrate 10 via the lens 40, the filter bar FB1 receives the composite optical signal L_com2. Next, a portion of the combined optical signal L_com2 passes through filter bar FB1 to generate filtered optical signal R21. The remaining portion of the combined optical signal L_com2 is reflected by filter bar FB1 to generate optical signal F21. Optical signal F21 is reflected by substrate 10 and received by filter bar FB2. Next, a portion of optical signal F21 passes through filter bar FB2 to generate filtered optical signal R22. The remaining portion of optical signal F21 is reflected by filter bar FB2 to generate optical signal F22. Optical signal F22 is reflected by substrate 10 and received by filter bar FB3. Next, a portion of optical signal F22 passes through filter bar FB3 to generate filtered optical signal R23. The remaining portion of optical signal F22 is reflected by filter bar FB3 to generate optical signal F23. Optical signal F23 is reflected by substrate 10 and received by filter bar FB4. When the optical signal F23 passes through the filter bar FB4, the optical signal F23 becomes the filtered optical signal R24. In the wavelength division device 100 of Figure 9, the prism 11 includes a first surface P1, a second surface P2, and a third surface P3. The second surface P2 is positioned adjacent to the first surface P1. The third surface P3 is positioned adjacent to the first surface P1 and the second surface P3.Furthermore, the third surface P3 is configured to receive multiple filtering optical signals R21 to R24. The second surface P2 is configured to reflect the multiple filtering optical signals R21 to R24 in order to generate multiple reflected optical signals L20 to L24. For example, filtering optical signal R21 is reflected by the second surface P2 to generate reflected optical signal L21. Filtering optical signal R22 is reflected by the second surface P2 to generate reflected optical signal L22. Filtering optical signal R23 is reflected by the second surface P2 to generate reflected optical signal L23. Filtering optical signal R24 is reflected by the second surface P2 to generate reflected optical signal L24. In other words, if the wavelength division device 100 is a wavelength division demultiplexer, the wavelength division device 100 can use wavelength selection components (i.e., filter bars FB1 to FB4, etc.) to separate specific wavelengths from the combined optical signal L_com2. Each wavelength carries a separate data channel. By doing so, the wavelength-division demultiplexer directs each channel to its corresponding output port.

[0026] Figure 10 shows the coating technique for the substrate 10 of the wavelength division device 100 when a multiplexing mechanism is performed. Figure 11 shows the coating technique for the substrate 10 of the wavelength division device 100 when a demultiplexing mechanism is performed. In this embodiment, to achieve optical division and optical coupling performance, an anti-reflective (AR) coating and a distributed Bragg reflector (DBR) coating can be introduced to the substrate 10 when a multiplexing mechanism or demultiplexing mechanism is performed. The AR coating is a microscopically thin layer of material applied to the surface of the lens 40. The AR coating can be designed to reduce light reflection and increase light transmittance. The DBR coating is a type of optical filter that reflects specific wavelengths of light while allowing other wavelengths to pass through. The DBR coating consists of multiple layers of alternately stacked materials having different refractive indices. The DBR coating structure can selectively reflect light of specific wavelengths based on their interference patterns. In this embodiment, the DBR coating can be considered a mirror on the edge face of the substrate 10 for reflecting optical signals.

[0027] Figure 12 is a flowchart for manufacturing the wavelength division apparatus 100. The wavelength division apparatus 100 can be manufactured according to steps S1201 to S1204. Any reasonable technical or hardware modifications are included within the scope of the present invention. Steps S1201 to S1204 are shown below. In step S1201, the surface of the substrate 10 is etched to form one or more grooves 10a. In step S1202, multiple filter bars FB1 to FB4 are coated. In step S1203, after coating the multiple filter bars FB1 to FB4, the multiple filter bars FB1 to FB4 are joined in one or more grooves 10a of the substrate 10. In step S1204, the resin 20 placed on the substrate 10 is imprinted using the processing mold 30 to form the prism 11.

[0028] The details of steps S1201 to S1204 have been described previously; therefore, they are omitted here. In the wavelength division apparatus 100, the glass wafer is etched to form one or more grooves 10a for filter bonding alignment, thereby improving the accuracy of filter alignment and positioning quality. Furthermore, the complexity of the filtering bonding alignment process can be reduced. As a result, the wavelength division apparatus 100 can be miniaturized.

[0029] In summary, the present invention discloses a wavelength division device and a method for manufacturing a wavelength division device. The wavelength division device includes a substrate having etched grooves for housing a plurality of filter bars. Prisms formed by imprinting resin onto the substrate cover the filter bars. The method for manufacturing the wavelength division device of the present invention simplifies the assembly process by pre-defining the positions of the filter bars in the grooves, resulting in a more compact and robust optical component suitable for various applications in optical communications.

[0030] Those skilled in the art will readily see that many modifications and changes can be made to the apparatus and method while maintaining the teachings of the present invention. Accordingly, the above disclosure should be construed as being limited only by the boundaries and scope of the appended claims.

Claims

1. A substrate having one or more grooves, A plurality of filter bars are arranged in one or more grooves of the substrate, each corresponding to an optical filtering wavelength, The substrate is disposed of and includes a prism configured to cover a plurality of filter bars, A wavelength splitting device comprising: etching the surface of the substrate to form one or more grooves; coating a plurality of filter bars; joining the plurality of filter bars in one or more grooves of the substrate; and imprinting the resin placed on the substrate by a processing mold to form the prism.

2. The apparatus according to claim 1, wherein one or more of the grooves have substantially the same depth and substantially the same width, and the substrate is a glass wafer.

3. The apparatus according to claim 1, wherein the surfaces of the plurality of filter bars are coated with different glass coating liquid materials, and the plurality of filter bars are joined in one or more grooves of the substrate by using an adhesive material having a refractive index matching that of glass.

4. The apparatus according to claim 1, wherein after a plurality of the filter bars are joined in one or more grooves of the substrate, the substrate is subjected to a thermosetting step for heating the adhesive material between the plurality of filter bars and one or more grooves, or to an ultraviolet (UV) light curing step for converting the adhesive material from a liquid state to a cured state.

5. The apparatus according to claim 1, wherein the processing die includes a predetermined pattern corresponding to the prism, the processing die presses the resin with a controlled force for a certain duration to form the prism, and after the duration has elapsed, the processing die is removed from the substrate.

6. The apparatus according to claim 1, wherein the substrate is cut to adjust the size of the wavelength division device.

7. The wavelength division device is a wavelength division multiplexer, and the prism is A first surface configured to receive multiple optical signals having multiple optical wavelengths, A second surface is positioned adjacent to the first surface and configured to reflect a plurality of light signals in order to generate a plurality of reflected light signals, The apparatus according to claim 1, further comprising: a third surface disposed adjacent to the first surface and the second surface and configured to receive a plurality of reflected light signals.

8. The apparatus according to claim 7, wherein the plurality of reflected light signals are received by the plurality of filter bars through the third surface of the prism, multiplexed, and a composite light signal is generated by the substrate.

9. The wavelength division device is a wavelength division demultiplexer, and the prism is A first surface configured to output multiple reflected light signals, A second surface is positioned adjacent to the first surface and configured to reflect a plurality of filtering light signals in order to generate a plurality of the reflected light signals, The apparatus according to claim 1, further comprising: a third surface disposed adjacent to the first surface and the second surface and configured to receive a plurality of filtering optical signals.

10. The apparatus according to claim 9, wherein the synthesized optical signal is demultiplexed and filtered by the substrate and the plurality of filter bars to generate a plurality of filtered optical signals.

11. The steps include etching the surface of the substrate to form one or more grooves, The steps include coating multiple filter bars, The steps include: coating the multiple filter bars and then joining the multiple filter bars in one or more grooves of the substrate; The step of imprinting the resin placed on the substrate using a processing mold to form a prism, A method for manufacturing a wavelength division device, wherein each of the plurality of filter bars corresponds to an optical filtering wavelength, and the prism is arranged on the substrate and configured to cover the plurality of filter bars.

12. The method according to claim 11, wherein one or more of the grooves have substantially the same depth and substantially the same width, and the substrate is a glass wafer.

13. The method according to claim 11, wherein the step of coating a plurality of filter bars is the step of coating the surfaces of a plurality of filter bars with different glass coating liquid materials, and the step of joining a plurality of filter bars in one or more grooves of a substrate is the step of joining a plurality of filter bars in one or more grooves of a substrate by using an adhesive material having a refractive index matching that of glass.

14. The method according to claim 11, further comprising the steps of: joining a plurality of filter bars in one or more grooves of the substrate; then treating the adhesive material between the plurality of filter bars and one or more grooves by a thermosetting process for heating; or treating the adhesive material by an ultraviolet (UV) light curing process for converting it from a liquid state to a cured state.

15. The step of imprinting the resin placed on the substrate using the aforementioned processing mold to form a prism is: The steps include forming the prism by pressing the resin with the processing die using a controlled force for a certain duration, The step includes removing the processing mold from the substrate after the aforementioned duration has elapsed, The method according to claim 11, wherein the processing die includes a predetermined pattern corresponding to the prism.

16. The process further includes the step of cutting the substrate to adjust the size of the wavelength division device, The method according to claim 11, wherein the substrate, the plurality of filter bars, and the prism form the wavelength division device.

17. The wavelength division device is a wavelength division multiplexer, and the prism is A first surface configured to receive multiple optical signals having multiple optical wavelengths, A second surface is positioned adjacent to the first surface and configured to reflect a plurality of light signals in order to generate a plurality of reflected light signals, The method according to claim 16, further comprising: a third surface disposed adjacent to the first surface and the second surface and configured to receive a plurality of reflected light signals.

18. The method according to claim 17, wherein the plurality of reflected light signals are received by the plurality of filter bars through the third surface of the prism, multiplexed, and a composite light signal is generated by the substrate.

19. The wavelength division device is a wavelength division demultiplexer, and the prism is A first surface configured to output multiple reflected light signals, A second surface is positioned adjacent to the first surface and configured to reflect a plurality of filtering light signals in order to generate a plurality of the reflected light signals, The method according to claim 16, further comprising: a third surface disposed adjacent to the first surface and the second surface and configured to receive a plurality of filtering optical signals.

20. The method according to claim 19, wherein the synthesized optical signal is demultiplexed and filtered by the substrate and the plurality of filter bars to generate a plurality of filtered optical signals.

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