Waveguide photodetector and system with integrated antenna, and method for transmitting signals

Abstract

The present invention provides an antenna-integrated waveguide photodetector and system, and a method for transmitting a signal, including a photodetector, N optical waveguides, and an antenna, where N is a positive integer, the antenna being provided on a substrate, and a feed gap being provided on the symmetrical axis of both arms of the antenna, the photodetector being provided within the feed gap, and the N optical waveguides being formed on the substrate, the photodetector being connected to the optical waveguides to acquire an optical carrier radio frequency signal transmitted through the optical waveguides. By providing a feed gap on the symmetrical axis of both arms of the antenna and providing the photodetector within the feed gap, the present invention allows the antenna and the photodetector to be integrated on the same device of the same chip, thereby improving the integration degree of optical integrated circuits and systems.

Description

Technical Field

[0001] The present invention relates to the technical field of optical integrated circuits, and particularly to a waveguide photodetector and a system in which an antenna is integrated, and a method for transmitting signals.

Background Art

[0002] A waveguide photodetector is a device that is commonly used in optical integrated circuits to convert an optical signal into an electrical signal. In some microwave photon applications, the optical signal passes through the waveguide photodetector and is absorbed by the waveguide photodetector to be converted into an electrical signal, and the electrical signal needs to be immediately radiated into free space.

[0003] The conventional method is to add a transmitting antenna outside the photodetector chip and package it into one system. Such release has low integration, complex packaging, and high cost.

[0004] Therefore, the present invention provides a waveguide photodetector and a system in which an antenna is integrated for improving the integration of a microwave photon system, and a method for transmitting signals.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a waveguide photodetector and a system in which an antenna is integrated for improving the integration of a microwave photon system, and a method for transmitting signals.

Means for Solving the Problems

[0006] According to a first aspect of the present invention, the present invention provides a waveguide photodetector in which an antenna is integrated, comprising a photodetector, N optical waveguides, and an antenna, wherein N is a positive integer, the antenna is provided on a substrate and a feed gap is provided at the symmetric axis positions of both arms of the antenna, the photodetector is provided within the feed gap, the N optical waveguides are formed on the substrate, and the photodetector is connected to the optical waveguides to acquire an optical carrier radio frequency signal transmitted on the optical waveguides.

[0007] The beneficial effect of this invention is that, by providing a power supply gap at the symmetrical axis positions of both arms of the antenna and providing the photodetector within the power supply gap, the antenna and the photodetector can be integrated on the same chip and the same device, thereby improving the integration density of the optical integrated circuit and system.

[0008] Selectively, the photodetector's operating frequency matches that of the antenna. The beneficial effect of this is that by matching the photodetector's operating frequency with that of the antenna, it helps the two work together better, thereby improving the operating efficiency of the waveguide photodetector in which the antenna is integrated, as described above.

[0009] Selectively, the antenna includes at least one of a Vivaldi antenna, a bowtie antenna, a slot antenna, and a patch antenna. The beneficial effect is that, because the antenna has multiple design configurations, the type of antenna can be modified to suit actual production needs, such as the antenna radiation area requirements.

[0010] More selectively, the substrate may include at least one of silicon, silicon-on-insulator, silicon-on-sapphire, silica, indium phosphide, lithium niobate, or polymer. The beneficial effect is that the waveguide photodetector on which the antenna is integrated can be integrated onto a substrate composed of one or more of the above materials to suit the needs of actual production.

[0011] Furthermore, the operating frequencies of the antenna may more selectively include the L-band frequency range, S-band frequency range, C-band frequency range, X-band frequency range, Ku-band frequency range, K-band frequency range, KA-band frequency range, and terahertz frequency range. The beneficial effect of this is that, by including multiple frequency types in the operating frequencies of the antenna, the waveguide photodetector into which the antenna is integrated can process signals of different frequency ranges.

[0012] Furthermore, the type of optical waveguide may be at least one of channel waveguides, ridge waveguides, slot waveguides, diffusion waveguides, and photonic crystal waveguides. The beneficial effect of this is that the type of optical waveguide may include multiple types, and different types of waveguides may have different cross-sectional areas, allowing for the selection of the appropriate optical waveguide type according to actual production needs.

[0013] Selectively, the photodetector includes at least one of a metal photodetector, a semiconductor photodetector, a metal-semiconductor photodetector, or an avalanche photodetector.

[0014] Selectively, the wavelength range of the optical signal includes at least one of the visible light band, O band, E band, S band, C band, L band, U band, and mid-infrared band.

[0015] According to a second aspect of the present invention, the present invention provides an antenna-integrated waveguide photodetector integration system that includes a waveguide photodetector in which K antennas described in any one embodiment of the first aspect are integrated, arranged in an array, wherein K is a positive integer of 2 or more.

[0016] The beneficial effect is that the waveguide photodetector integrated system, in which the antennas are integrated, can be used in phased array radar applications to complete target search, tracking, and measurement.

[0017] According to a third aspect, the present invention provides a method for transmitting a signal, which is applied to a waveguide photodetector in which an antenna described in any one embodiment of the first aspect is integrated, the optical waveguide acquires an optical carrier radio frequency signal and transmits the optical carrier radio frequency signal to the photodetector, the photodetector receives the optical carrier radio frequency signal from the optical waveguide, converts the optical carrier radio frequency signal into an electrical radio frequency signal and transmits the electrical radio frequency signal to the antenna, and the antenna acquires the electrical radio frequency signal from the photodetector and transmits the electrical radio frequency signal.

[0018] The beneficial effect is that, by applying the present invention to a waveguide photodetector in which the antenna described in any one of the embodiments above is integrated, it is possible to ensure signal transmission efficiency while simultaneously improving the integration density of the optical integrated circuit, in order to meet the needs of actual production.

[0019] Selectively, the method for transmitting a signal as described above further includes obtaining the frequency range of the radio frequency signal and, if the frequency range of the radio frequency signal does not meet a predetermined requirement, modifying or adjusting the design of at least one of the antenna and the photodetector so that the frequency range of the radio frequency signal meets the predetermined requirement. The beneficial effect is that by modifying or adjusting the design of the antenna and the photodetector, the frequency range of the radio frequency signal meets the actual needs.

[0020] Selectively, the method of transmitting a signal as described above includes adjusting the design of the antenna based on a radiation direction diagram so that the radiation direction of the radio frequency signal satisfies the predetermined requirements. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic diagram of an embodiment of a waveguide photodetector in which the antenna according to the present invention is integrated. [Figure 2]Schematic diagram of an embodiment of a waveguide photodetector in which another antenna according to the present invention is integrated. [Figure 3] Schematic diagram of an embodiment of a waveguide photodetector integration system in which an antenna according to the present invention is integrated. [Figure 4] Method flowchart for transmitting a signal according to the present invention. [Figure 5] Schematic diagram of an embodiment of the simulation result of the radiation pattern of a Vivaldi antenna according to the present invention. [Figure 6] Schematic diagram of an embodiment of the simulation result of the performance of a photodetector according to the present invention.

Embodiments for Carrying Out the Invention

[0022] The following describes the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Here, in the description of the embodiments of the present application, the terms used in the following embodiments are only for describing specific embodiments and are not intended as limitations to the present application. As used in the specification and the appended claims of the present application, the singular forms "one", "the", "above", "the" and "this" are intended to include, for example, the expression forms such as "one or more" unless clearly indicated to the contrary in the context. In each of the following embodiments of the present application, "at least one" and "one or more" refer to one or two or more (including two). The term "and / or" is used to describe the relationship of related objects and indicates that three relationships may exist. For example, A and / or B may represent three cases: A alone, the combination of A and B, and B alone. Here, A and B may be singular or plural. The character " / " generally represents that the related objects before and after are in an "or" relationship.

[0023] References such as "one embodiment" or "some embodiments" described in this specification mean that one or more embodiments of the present application include specific features, structures, or characteristics described in relation to that embodiment. Accordingly, statements such as "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments also" that appear in different places in this specification do not necessarily all refer to the same embodiment, and unless otherwise particularly emphasized, mean "one or more embodiments, but not all". The terms "comprising", "containing", "having" and their variants mean "including but not limited to" unless otherwise particularly emphasized. The term "connection" includes direct connection and indirect connection unless otherwise described. "First", "second" are used only for the purpose of description and should not be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features.

[0024] In the embodiments of the present application, terms such as "exemplarily" or "for example" are used to represent as an example, illustration, or explanation. In the embodiments of the present application, any embodiment or design solution described as "exemplarily" or "for example" should not be construed as being more preferable or having more advantages than other embodiments or design solutions. To be exact, using terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0025] In order to improve the integration degree of an optical integrated circuit, the present invention provides a waveguide photodetector in which an antenna including a photodetector 1, N optical waveguides (as shown by the optical waveguide 2 in FIG. 1), and an antenna 3 is integrated, where N is a positive integer, the antenna 3 is provided on one substrate, and a feeding gap is provided at the symmetric axis position of both arms of the antenna 3, the photodetector 1 is provided in the feeding gap, N optical waveguides (as shown by the optical waveguide 2 in FIG. 1) are formed on the substrate, and the photodetector 1 is connected to the optical waveguide 2 so as to acquire an optical carrier radio frequency signal transmitted on the optical waveguide 2.

[0026] In this embodiment, using only the optical waveguide 2 as an example, the structure of the waveguide photodetector in which the antenna is integrated, as described above, is explained. The number of optical waveguides to which the photodetector can be connected in Figure 1 is not limited, and N is set according to the actual requirements. N may be 1 or a large number. In this invention, a feed gap is provided at the symmetric axis positions of both arms of the antenna 3, and the photodetector 1 is provided within the feed gap, thereby enabling the antenna 3 and the photodetector 1 to be integrated on the same chip, and thereby improving the integration density of the optical integrated circuit.

[0027] In one possible embodiment, the photodetector's operating frequency matches that of the antenna. In this embodiment, matching the photodetector's operating frequency with that of the antenna helps facilitate better cooperation between the two, thereby improving the operational efficiency of the waveguide photodetector in which the antenna is integrated, as described above.

[0028] In another possible embodiment, the antenna includes at least one of a Vivaldi antenna, a bowtie antenna, a slot antenna, and a patch antenna. In this embodiment, since the antenna has multiple design schemes, the type of antenna can be modified to suit actual production needs such as antenna radiation area needs. For example, the antenna shown in Figure 1 is a Vivaldi antenna, and the antenna shown in Figure 2 is a bowtie antenna. That is, the aforementioned waveguide photodetector in which the antenna is integrated, shown in Figure 2, includes a photodetector 1, an optical waveguide 2, and an antenna 4, and the antenna 4 is a bowtie antenna. This embodiment satisfies different application needs by modifying the type of antenna in the aforementioned waveguide photodetector in which the antenna is integrated.

[0029] In further possible embodiments, the substrate comprises at least one of silicon, silicon-on-insulator, silicon-on-sapphire, silica, indium phosphide, lithium niobate, and polymer. In this embodiment, the waveguide photodetector on which the antenna is integrated, as described above, can be integrated on a substrate composed of any one or more of the above materials to suit the needs of actual production.

[0030] In one possible embodiment, the operating frequencies of the antenna include the L-band frequency range, S-band frequency range, C-band frequency range, X-band frequency range, Ku-band frequency range, K-band frequency range, KA-band frequency range, and terahertz frequency range. The X-band refers to the radio wave band with frequencies from 8 to 12 GHz and belongs to the microwave range in the electromagnetic spectrum. In some cases, the frequency range of the X-band may be from 7 to 11.2 GHz. The frequency of the Ku-band is the 12 to 18 GHz frequency band. The aperture of the antenna for receiving the Ku-band radio waves is relatively small, thereby effectively reducing reception costs. The terahertz frequency range includes electromagnetic waves with frequencies from 0.1 to 10 THz. Terahertz is applied to frequencies between the high-frequency edge (300 GHz) of the millimeter-wave band and the low-frequency far-infrared spectral band edge (3000 GHz) radiated from electromagnetic waves, with the radiation of the corresponding wavelengths ranging from 0.03 mm to 3 mm (or 30 to 3000 μm) in that frequency band range. Since the photon energy of a photon with a frequency of 1 THz is only about 4 millielectron volts, it is unlikely to damage the material being detected. In this embodiment, by including multiple frequency types in the operating frequency of the antenna, the waveguide photodetector in which the antenna is integrated can process optical signals in different frequency ranges.

[0031] In another possible embodiment, the type of optical waveguide includes at least one of channel waveguides, ridge waveguides, slot waveguides, diffusion waveguides, and photonic crystal waveguides. Here, common types of optical waveguides are channel waveguides and ridge waveguides, and in this embodiment, the type of optical waveguide includes multiple types, and the appropriate type of optical waveguide is selected according to the actual production needs by having different cross-sectional areas of different types of waveguides.

[0032] In further possible embodiments, the photodetector may include at least one of a metal photodetector, a semiconductor photodetector, a metal-semiconductor photodetector, or an avalanche photodetector. Different types of photodetectors are applied to different application scenarios.

[0033] In one possible embodiment, the wavelength range of the optical signal includes at least one of the visible light band, O band, E band, S band, C band, L band, U band, and mid-infrared band.

[0034] Based on the waveguide photodetector in which the antennas described in any one of the embodiments described above are integrated, the present invention provides a waveguide photodetector integration system in which antennas are integrated, comprising K waveguide photodetectors in which the antennas described in any one of the embodiments described above are integrated, arranged in an array, wherein K is a positive integer of 2 or more.

[0035] As shown in Figure 3, the aforementioned waveguide photodetector integrated system with integrated antennas includes nine waveguide photodetectors 100 with integrated antennas arranged in a matrix, and since K is a positive integer of 2 or more, the aforementioned waveguide photodetector integrated system with integrated antennas includes at least two of the aforementioned waveguide photodetectors with integrated antennas, and the array composed of the aforementioned waveguide photodetectors with integrated antennas may have an irregular shape. The aforementioned waveguide photodetector integrated system with integrated antennas can be used in phased array radar applications to complete search, tracking, and measurement of a target. The aforementioned waveguide photodetectors with integrated antennas can also be configured from the aforementioned waveguide photodetectors with integrated antennas to improve the integration density of optical integrated devices and systems.

[0036] Furthermore, based on the waveguide photodetector in which the antenna is integrated as described above in any one of the embodiments of the above paragraph, the present invention provides a method for transmitting a signal, and the method flow, as shown in Figure 4, specifically includes the following steps.

[0037] S401, The optical waveguide acquires an optical carrier radio frequency signal and transmits the optical carrier radio frequency signal to the photodetector.

[0038] S402, The photodetector receives the optical carrier radio frequency signal from the optical waveguide, converts the optical carrier radio frequency signal into an electrical radio frequency signal, and transmits the electrical radio frequency signal to the antenna.

[0039] S403, The antenna acquires the radio frequency signal from the photodetector and transmits the radio frequency signal.

[0040] The present invention can be applied to a method for transmitting signals using a waveguide photodetector that integrates the antenna described in any one of the embodiments above, thereby ensuring signal transmission efficiency while simultaneously improving the integration density of the optical integrated circuit, in order to meet the needs of actual production.

[0041] In one possible embodiment, the method for transmitting a signal as described above further includes obtaining the frequency range of the radio frequency signal and, if the frequency range of the radio frequency signal does not meet a predetermined requirement, modifying or adjusting the design of at least one of the antenna and the photodetector so that the frequency range of the radio frequency signal meets the predetermined requirement. In this embodiment, the frequency range of the radio frequency signal is adapted to the actual needs by modifying at least one of the size of the antenna, the RC parameters of the photodetector, or the carrier travel time of the photodetector. In one possible embodiment, the method for transmitting a signal as described above further includes adjusting the antenna design based on a required radiation direction diagram. For example, if the antenna used is a Vivaldi antenna and the outlines of the antenna are as shown in (a), (b), and (c) in Figure 5, then in Figure 5(b), a feeding gap is provided between the first and second arms of the antenna, and a photodetector is provided within the feeding gap. The radiation direction diagrams of the waveguide photodetector in which the antenna is integrated are shown in Figures 5(A), (B), and (C), respectively, where "y" in Figure 5 represents the y-axis in the coordinate system, "z" in Figure 5 represents the z-axis in the coordinate system, and the direction of the x-axis (not shown) is perpendicular to the plane in which the y-axis and z-axis are located. In Figures 5(A), (B), and (C), the solid lines represent the radiation direction diagrams of the waveguide photodetector in which the antenna is integrated, corresponding to the yz-plane, and the dashed lines represent the radiation direction diagrams of the waveguide photodetector in which the antenna is integrated, corresponding to the xy-plane.

[0042] The specific structure of the photodetector and the absorbing material on the photodetector as referred to in this application are not limited. For example, the absorbing material includes germanium, silicon, III-V material, and metal. The specific location of the contacts on the photodetector for connection to the antenna is not limited. When the absorbing material on the photodetector is germanium, the simulation results of the performance of the photodetector are shown in Figure 6. In Figure 6(a), the horizontal axis represents the optical propagation distance in microns (um), the vertical axis represents the normalized total absorption efficiency, and Figure 6(a) shows the situation in which the normalized total absorption efficiency changes with respect to the optical propagation distance within the absorption region, the horizontal axis represents the wavelength in nanometers (nm), the vertical axis represents the optical response rate, and Figure 6(b) shows the situation in which the optical response rate changes with respect to the wavelength near the O band.

[0043] The above description is merely a specific embodiment of the embodiment of the present application; however, the scope of protection of the embodiment of the present application is not limited thereto. Any modification or substitution within the technical scope presented in the embodiment of the present application should also be included within the scope of protection of the embodiment of the present application. Therefore, the scope of protection of the embodiment of the present application should be based on the scope of protection of the claims.

Claims

1. A waveguide photodetector integration system that includes an antenna integration system, which includes a waveguide photodetector in which K antennas arranged in an array are integrated, The waveguide photodetector in which the aforementioned antenna is integrated is It includes a photodetector, N optical waveguides, and a Vivaldi antenna or bowtie antenna, where N is a positive integer. The antenna is provided on the substrate, and a power supply gap is provided at the symmetrical axis positions of both arms of the antenna, and the photodetector is provided within the power supply gap. The shape of the antenna extends in the radial direction from the symmetrical axis position of both arms on which the photodetectors are provided. N optical waveguides are formed on the substrate, and the photodetector is connected to the optical waveguide to acquire the optical carrier radio frequency signal transmitted on the optical waveguide. The photodetector matches the operating frequency of the antenna, A waveguide photodetector integration system in which antennas are integrated, characterized in that K is a positive integer of 2 or more.

2. The waveguide photodetector integration system in which the antenna according to claim 1 is integrated is characterized in that the substrate comprises at least one of silicon, silicon-on-insulator, silicon-on-sapphire, silica, indium phosphide, lithium niobate, and polymer.

3. Waveguide photodetector integration system in which the antenna according to claim 1 is integrated is characterized in that the operating frequency range of the antenna includes the L-band frequency range, S-band frequency range, C-band frequency range, X-band frequency range, Ku-band frequency range, K-band frequency range, KA-band frequency range and terahertz frequency range.

4. The waveguide photodetector integration system in which the antenna according to claim 1 is integrated is characterized in that the type of optical waveguide includes at least one of channel waveguides, ridge waveguides, slot waveguides, diffuse waveguides, and photonic crystal waveguides.

5. The waveguide photodetector integration system in which the antenna according to claim 1 is integrated is characterized in that the photodetector includes at least one of a metal photodetector, a semiconductor photodetector, a metal-semiconductor photodetector, and an avalanche photodetector.

6. The waveguide photodetector integration system in which the antenna according to claim 1 is integrated is characterized in that the wavelength range of the optical carrier radio frequency signal includes at least one of the visible light band, O band, E band, S band, C band, L band, U band, and mid-infrared band.

7. It is intended to be applied to a waveguide photodetector integration system in which the antenna described in any one of claims 1 to 6 is integrated, The optical waveguide acquires an optical carrier radio frequency signal and transmits the optical carrier radio frequency signal to the photodetector. The photodetector receives the optical carrier radio frequency signal from the optical waveguide, converts the optical carrier radio frequency signal into an electrical radio frequency signal, and transmits the electrical radio frequency signal to the antenna. A method for transmitting a signal, characterized in that the antenna acquires the radio frequency signal from the photodetector and transmits the radio frequency signal.

8. A method for transmitting a signal according to claim 7, further comprising obtaining the frequency range of the radio frequency signal, and if the frequency range of the radio frequency signal does not satisfy a preset requirement, modifying or adjusting the design of at least one of the antenna and the photodetector so that the frequency range of the radio frequency signal satisfies the preset requirement.

9. A method for transmitting a signal according to claim 8, comprising adjusting the design of the antenna based on a radiation direction diagram so that the radiation direction of the radio frequency signal satisfies the predetermined requirements.

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