All-optical triode light modulation system, modulation method and application thereof

Abstract

The invention provides an all-optical triode light modulation system, a modulation method and application thereof. The all-optical triode light modulation system comprises a pump light source, a signal light source and a micro-ring modulator, wherein the micro-ring modulator comprises a micro-ring resonator and a Van der Waals material; pump light output by the pump light source enters the Van der Waals material from one side to generate resonance light absorption, and signal light output by the signal light source is coupled into the micro-ring resonator and interacts with the Van der Waals material, so that the signal light is modulated by the pump light. The all-optical modulation system which is simple in structure, high in modulation rate and short in response time is prepared by utilizing the limited band gap and resonance light absorption of visible and near-infrared bands of Van der Waals semiconductor materials and the resonance characteristic of the silicon-based micro-ring resonant cavity, rapid modulation of communication optical signals is achieved, and the communication efficiency is improved. And all-optical modulation of optical phase and / or amplitude can be realized.

Description

Technical Field

[0001] The present invention belongs to the field of information communication technology, and in particular relates to an all-optical triode light modulation system, a modulation method and an application thereof. Background Art

[0002] Optical modulators play a role in modulating carrier optical signals in optical fiber systems. They are a key factor in achieving high-speed transmission and processing of optical signals. They are key components of modern telecommunication networks and microwave photonic systems, and are also the cornerstone of emerging fields such as quantum photonics. As existing and emerging technologies have increasingly higher requirements for compact, efficient, fast, and broadband optical processing, the demand for electro-optic modulators with higher performance and smaller size is becoming more and more urgent. It is necessary to find optical material systems with stronger light confinement capabilities, better modulation effects, and easy integration.

[0003] However, existing optical modulation technology still faces a series of urgent problems to be solved. Specifically, traditional optical modulation has limited depth, making it difficult to achieve the requirements of efficient signal conversion; high energy consumption increases system operating costs and limits its feasibility in large-scale deployment; limited material selection, existing materials have deficiencies in nonlinear effects, optical absorption, etc., which limits the improvement of modulation performance; insufficient technical maturity, some key technologies have not yet reached commercial standards, affecting their promotion in practical applications; and system integration is difficult, and compatibility and interoperability with existing optical communication systems need to be further optimized.

[0004] All-optical triodes use light waves to replace electron flow and use photons as the medium to perform signal scaling and regulation tasks. This concept deeply integrates nonlinear optics, laser engineering and advanced materials science, and is committed to developing a new generation of light-controlled devices that can effectively control the intensity and phase of optical signals, in order to play a key role in optical communications, optical computing and even future quantum information processing. However, although traditional optical triodes have a certain application basis in the field of optoelectronics, their inherent defects cannot be ignored. The main problem is that traditional triodes generally use semiconductor materials such as silicon and germanium. The band structure of these materials limits their effective application in specific optical bands (such as ultraviolet and infrared), and their physical and chemical properties make the device performance easily damaged in harsh environments such as high temperature and high humidity. In addition, the carrier mobility and recombination rate of semiconductor materials are limited, resulting in limited modulation efficiency and bandwidth, which is difficult to meet the needs of modern high-speed and broadband optical communication systems. At the same time, the manufacturing process of traditional optical triodes is complex, the integration is difficult, the cost is high, and the performance is easily degraded after long-term operation, and the stability and reliability are insufficient.

[0005] In contrast, optical triodes based on van der Waals materials show significant advantages. Van der Waals materials have unique band structures and excellent light absorption properties, which can achieve efficient photoelectric conversion in a wider optical band. These materials usually have excellent chemical and thermal stability and can maintain stable performance in harsh environments. More importantly, the excitons and polaritons in van der Waals materials have fast and efficient excitation and relaxation processes, which enables optical triodes based on these materials to achieve high-speed and efficient light modulation with a wider modulation bandwidth, meeting the needs of modern high-speed and broadband optical communication systems. This makes optical triodes based on van der Waals materials have broader application prospects and higher performance in the field of modern optoelectronics. Summary of the invention

[0006] Therefore, the purpose of the present invention is to overcome the defects in the prior art and provide an all-optical triode light modulation system, a modulation method and application thereof.

[0007] In view of the slow modulation speed of electro-optic modulators, the immature processing technology and lack of stability of existing all-optical modulators, an all-optical triode optical modulation system based on van der Waals semiconductor materials is proposed. The present invention utilizes the limited band gap and resonant light absorption of van der Waals semiconductor materials in the visible and near-infrared bands and the resonant characteristics of silicon-based microring resonators to prepare an all-optical modulation system with a simple structure, fast modulation rate and short response time, so as to achieve rapid modulation of communication optical signals.

[0008] Before describing the present invention, the terms used in this article are defined as follows:

[0009] The term "TMDs" refers to: transition metal dichalcogenides.

[0010] The term "single-mode optical fiber" refers to an optical fiber that has only one transmission mode, and the core diameter of the glass core at the transmission center is usually relatively small, including but not limited to a core diameter of only 9 or 10 μm.

[0011] To achieve the above-mentioned object, the first aspect of the present invention provides an all-optical triode optical modulation system, the all-optical triode optical modulation system comprising: a pump light source, a signal light source and a micro-ring modulator, the micro-ring modulator comprising a micro-ring resonator and a van der Waals material; wherein,

[0012] The pump light output by the pump light source is incident on the van der Waals material from one side to generate resonant light absorption, and the signal light output by the signal light source is coupled into the microring resonator and interacts with the van der Waals material, so that the pump light modulates the signal light.

[0013] According to the all-optical triode optical modulation system of the first aspect of the present invention, the microring resonator comprises a straight waveguide and a microring waveguide; wherein,

[0014] The materials of the straight waveguide and the microring waveguide are selected from one or more of the following: silicon, silicon nitride, silicon dioxide, preferably silicon or silicon nitride, most preferably silicon.

[0015] According to the all-optical triode light modulation system of the first aspect of the present invention,

[0016] The radius of the microring waveguide is 0.2-0.6 μm, preferably 0.3-0.5 μm, more preferably 0.35-0.45 μm; and / or

[0017] The gap width between the straight waveguide and the microring waveguide is 50 to 150 nm, preferably 80 to 120 nm, and more preferably 90 to 100 nm.

[0018] According to the all-optical triode light modulation system of the first aspect of the present invention, the micro-ring modulator further comprises a grating coupler and / or a signal generator; wherein,

[0019] The signal light is coupled into the straight waveguide through the grating coupler, and then coupled into the microring resonator; and / or

[0020] The signal generator is used to modulate the pump light and inject it into the van der Waals material through a single-mode optical fiber.

[0021] According to the all-optical triode light modulation system of the first aspect of the present invention,

[0022] The van der Waals material covers the microring waveguide of the microring resonator; and / or

[0023] The band gap of the van der Waals material is 0 eV to 2.5 eV, preferably 1.0 eV to 2.3 eV, and more preferably 1.5 eV to 2.1 eV.

[0024] According to the all-optical triode light modulation system of the first aspect of the present invention, the van der Waals material is selected from one or more of the following: graphene, TMDs, black phosphorus, preferably graphene or TMDs, most preferably TMDs; wherein,

[0025] The chemical formula of the TMDs is MX2, wherein:

[0026] M is a transition metal element, preferably selected from one or more of the following: Ti, V, Ta, Mo, W, Re, more preferably selected from one or more of the following: Ti, Mo, W, Re, further preferably Mo or W;

[0027] X is selected from one or more of the following: S, Se, Te, more preferably S or Se, most preferably S;

[0028] Preferably, the TMDs are selected from one or more of the following: molybdenum disulfide, molybdenum diselenide, tungsten disulfide, tungsten diselenide, molybdenum ditelluride, tungsten ditelluride, more preferably selected from one or more of the following: molybdenum disulfide, molybdenum diselenide, tungsten disulfide, tungsten diselenide.

[0029] According to the all-optical triode light modulation system of the first aspect of the present invention,

[0030] The wavelength of the pump light is 400 to 700 nm, preferably 450 to 650 nm, more preferably 500 to 600 nm; and / or

[0031] The wavelength of the signal light is 1500-1600 nm, preferably 1520-1570 nm, and more preferably 1530-1550 nm.

[0032] A second aspect of the present invention provides a light modulation method, the modulation method comprising using the all-optical triode light modulation system of the first aspect to modulate light;

[0033] Preferably, the light modulation includes: full optical modulation of optical phase and / or full optical modulation of optical amplitude.

[0034] A second aspect of the present invention provides a light modulation method, the modulation method comprising using the all-optical triode light modulation system of the first aspect to modulate light, the modulation method comprising:

[0035] The pump light output by the pump light source is modulated by the signal generator and then incident on the microring waveguide covered with the van der Waals material through a single-mode optical fiber, and undergoes resonant light absorption to change the refractive index of the van der Waals material; the signal light is coupled to the straight waveguide through the grating coupler, and then coupled to the microring resonator, interacting with the van der Waals material, so that the pump light modulates the signal light and outputs a waveform consistent with the pump light, so as to achieve all-optical modulation of the optical phase and / or all-optical modulation of the amplitude.

[0036] The third aspect of the present invention provides the use of the all-optical triode optical modulation system described in the first aspect in preparing a device for realizing the all-optical modulation function of optical phase and / or all-optical modulation function of optical amplitude.

[0037] According to a preferred embodiment of the present invention, the working method of the all-optical triode light modulation system of the present invention is as follows:

[0038] The test process of the all-optical triode optical modulation system is as follows: Figure 1As shown, a tapered optical fiber is used to inject the pump light source into the silicon-based microring covered with van der Waals material. The energy of the pump light used is far higher than the energy level of the tungsten disulfide band gap, so it acts as an absorber for the pump light. The grating coupler couples the continuous input signal light in the near-infrared communication band into the silicon-based straight waveguide, and then couples it to the microring resonator. When the signal light passes through the covered van der Waals material, the strong interaction between the optical field in the waveguide and the van der Waals material enables the pump light to effectively modulate the signal light, thereby outputting a waveform consistent with the pump light.

[0039] The working principle of the all-optical triode light modulation of the present invention is as follows:

[0040] All-optical modulation is to modulate the input signal light (continuous light) with a beam of pump light. Under the excitation of laser pulses, the carrier density and distribution of two-dimensional materials will undergo huge changes, causing changes in the real and imaginary parts of their complex refractive index. Based on the all-optical triode optical modulation system based on van der Waals semiconductor materials, the modulated pump light is incident on the microring van der Waals material from one side, and the resonant light absorption of the van der Waals material causes the refractive index of the material to change. The change in the refractive index of the van der Waals material at the microring can further affect the real or imaginary part of the effective refractive index of the input signal light of the silicon waveguide below, resulting in changes in the phase or intensity of the signal light, thereby achieving optical phase or amplitude modulation.

[0041] Compared with the prior art, the all-optical triode light modulation system, its modulation method and application of the present invention can have but are not limited to the following beneficial effects:

[0042] The present invention utilizes the limited band gap and resonant light absorption of van der Waals semiconductor materials in the visible and near-infrared bands and the resonant characteristics of a silicon-based microring resonant cavity to prepare an all-optical modulation system with a simple structure, fast modulation rate and short response time, thereby realizing rapid modulation of communication optical signals and all-optical modulation of optical phase and / or all-optical modulation of optical amplitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0044] Figure 1 The working schematic diagram of the all-optical triode light modulation system of the present invention is shown.

[0045] Figure 2 The waveform diagram shows that the pump light and the output signal light are sinusoidal waves.

[0046] Figure 3 The waveform diagram shows that the pump light and the output signal light are square waves.

[0047] Figure 4 The waveform diagram shows that the pump light and the output signal light are triangular waves.

[0048] Figure 5 The structure diagram of the all-optical triode light modulation system of the present invention is shown. DETAILED DESCRIPTION

[0049] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings. However, it should be understood that these embodiments are only used for more detailed and specific description and should not be understood as limiting the present invention in any form.

[0050] This section generally describes the materials and test methods used in the experiments of the present invention. Although many materials and operating methods used to achieve the purpose of the present invention are well known in the art, the present invention is still described as detailed as possible. It is clear to those skilled in the art that in the context, if not specifically stated, the materials and operating methods used in the present invention are well known in the art.

[0051] Example 1

[0052] This embodiment is an exemplary description of the all-optical triode light modulation system and modulation method of the present invention.

[0053] The all-optical triode optical modulation system of the present invention comprises: a pump light source, a signal light source and a micro-ring modulator, wherein the micro-ring modulator comprises a micro-ring resonator and a van der Waals material, wherein the micro-ring resonator comprises a straight waveguide and a micro-ring waveguide, and the van der Waals material is covered on the micro-ring waveguide of the micro-ring resonator. Figure 5 shown.

[0054] The microring modulator further comprises a grating coupler and a signal generator, wherein the signal light is coupled into the straight waveguide through the grating coupler and then coupled into the microring resonator. The signal generator is used to modulate the pump light.

[0055] In this embodiment, the van der Waals material is tungsten disulfide, whose band gap is 2.1eV, and the materials of the straight waveguide and the micro-ring waveguide are silicon. The radius of the micro-ring waveguide is 10 μm, the gap width between the straight waveguide and the micro-ring waveguide is 90 nm, the wavelength of the pump light is 520 nm, and the wavelength of the signal light is 1539 nm.

[0056] The working method of the all-optical triode light modulation system of the present invention is as follows:

[0057] The test process of the all-optical triode optical modulation system is as follows: Figure 1As shown, a tapered optical fiber is used to irradiate pump light onto the microring waveguide covered with van der Waals material. The energy of the pump light used far exceeds the band gap of tungsten disulfide, so it acts as an absorber for the pump light. The grating coupler couples the continuous input signal light in the near-infrared communication band into the silicon-based straight waveguide, and then couples it into the microring resonator. When the signal light passes through the van der Waals material, the evanescent field in the waveguide strongly interacts with the van der Waals material, which enables the pump light to effectively modulate the signal light, thereby outputting a waveform consistent with the pump light to achieve optical phase modulation and / or optical amplitude modulation.

[0058] Embodiment 2-3

[0059] This embodiment is another exemplary description of the all-optical triode light modulation system of the present invention.

[0060] The all-optical triode light modulation systems of Examples 2 to 3 are the same as those of Example 1 except for the conditions listed in Table 1.

[0061] Table 1 All-optical triode light modulation system of Examples 2 to 3

[0062]

[0063] Example 4

[0064] This embodiment is a performance test result of the all-optical triode light modulation system of the present invention.

[0065] This embodiment uses the all-optical triode light modulation system of embodiments 1 to 3 to perform the following tests.

[0066] In this measurement, the wavelengths of the pump light source and the signal light are shown in Table 1 and Example 1, respectively. The pump light signal is modulated using a signal generator and then irradiated at the microring waveguide covered with van der Waals material through a single-mode tapered optical fiber. The continuous signal light is coupled into the straight waveguide by a grating. The optical signal received from the output port of the straight waveguide is a modulated signal. Finally, the output signal light is coupled into a near-infrared photodetector, which converts the optical signal into an electrical signal for display on an oscilloscope.

[0067] The pump light source is controlled by a signal generator, and the input signal light is modulated under the input of sine wave, square wave and triangle wave. The results are as follows: Figures 2 to 4As shown. The frequency of the pump light is 1 kHz, and the optical power is 0.5 mW. The input signal light is continuous light, and the optical power is 10 mW. Under the excitation of the modulated pump light, the frequency and waveform of the output signal light of the all-optical triode optical modulation system of Examples 1 to 3 are the same as the pump light, indicating that the all-optical modulation of the signal light is achieved. When the pump light is a sine wave and a triangular wave waveform input, the input power of the pump light of the all-optical triode optical modulation system of Examples 1 to 3 changes continuously in the range of 0-0.5 mW, and the intensity of the output optical signal increases linearly with the increase of the input power of the excitation light. This is because the light absorption of the van der Waals material is proportional to the pump light power before reaching saturation absorption. The change in optical power mainly affects the absorption of the material, thereby affecting the imaginary part of the refractive index, thereby achieving modulation of the amplitude of the signal light. When the pump light is a square wave (switch) waveform input, the main effect is the phase of the output signal light, thereby achieving phase modulation of the signal light.

[0068] Although the effects of some embodiments are shown above, those skilled in the art should understand that according to the concept of the present invention, the aforementioned other embodiments without specific effects or other technical solutions of the present invention not shown in the embodiments can also achieve the following technical effects stated in the invention content section that are equivalent to the embodiments:

[0069] The present invention utilizes the limited band gap and resonant light absorption of van der Waals semiconductor materials in the visible and near-infrared bands and the resonant characteristics of a silicon-based microring resonant cavity to prepare an all-optical modulation system with a simple structure, fast modulation rate and short response time, thereby realizing rapid modulation of communication optical signals and all-optical modulation of optical phase and / or all-optical modulation of optical amplitude.

[0070] Although the present invention has been described to a certain extent, it is obvious that appropriate changes in various conditions can be made without departing from the spirit and scope of the present invention. It is understood that the present invention is not limited to the embodiments described, but belongs to the scope of the claims, which includes equivalent replacements of each factor described.

Claims

1. An all-optical triode light modulation system, characterized in that: The all-optical triode light modulation system comprises: a pump light source, a signal light source and a micro-ring modulator, wherein the micro-ring modulator comprises a micro-ring resonator and a van der Waals material; wherein, The pump light output by the pump light source is incident on the van der Waals material from one side to generate resonant light absorption, and the signal light output by the signal light source is coupled into the microring resonator and interacts with the van der Waals material, so that the pump light modulates the signal light.

2. The all-optical triode light modulation system according to claim 1, characterized in that: The microring resonator comprises a straight waveguide and a microring waveguide; wherein, The materials of the straight waveguide and the microring waveguide are selected from one or more of the following: silicon, silicon nitride, silicon dioxide, preferably silicon or silicon nitride, most preferably silicon.

3. The all-optical triode light modulation system according to claim 2, characterized in that: The radius of the microring waveguide is 0.2-0.6 μm, preferably 0.3-0.5 μm, more preferably 0.35-0.45 μm; and / or The gap width between the straight waveguide and the microring waveguide is 50 to 150 nm, preferably 80 to 120 nm, and more preferably 90 to 100 nm.

4. The all-optical triode light modulation system according to claim 2 or 3, characterized in that: The micro-ring modulator further includes a grating coupler and / or a signal generator; wherein, The signal light is coupled into the straight waveguide through the grating coupler, and then coupled into the microring resonator; and / or The signal generator is used to modulate the pump light and inject it into the van der Waals material through a single-mode optical fiber.

5. The all-optical triode light modulation system according to any one of claims 2 to 4, characterized in that: The van der Waals material covers the microring waveguide of the microring resonator; and / or The band gap of the van der Waals material is 0 eV to 2.5 eV, preferably 1.0 eV to 2.3 eV, and more preferably 1.5 eV to 2.1 eV.

6. The all-optical triode light modulation system according to any one of claims 1 to 5, characterized in that: The van der Waals material is selected from one or more of the following: graphene, TMDs, black phosphorus, preferably graphene or TMDs, most preferably TMDs; wherein, The chemical formula of the TMDs is MX2, wherein: M is a transition metal element, preferably selected from one or more of the following: Ti, V, Ta, Mo, W, Re, more preferably selected from one or more of the following: Ti, Mo, W, Re, further preferably Mo or W; X is selected from one or more of the following: S, Se, Te, more preferably S or Se, most preferably S; Preferably, the TMDs are selected from one or more of the following: molybdenum disulfide, molybdenum diselenide, tungsten disulfide, tungsten diselenide, molybdenum ditelluride, tungsten ditelluride, more preferably selected from one or more of the following: molybdenum disulfide, molybdenum diselenide, tungsten disulfide, tungsten diselenide.

7. The all-optical triode light modulation system according to any one of claims 1 to 6, characterized in that: The wavelength of the pump light is 400 to 700 nm, preferably 450 to 650 nm, more preferably 500 to 600 nm; and / or The wavelength of the signal light is 1500-1600 nm, preferably 1520-1570 nm, and more preferably 1530-1550 nm.

8. A method for modulating light, characterized in that: The modulation method comprises modulating light using the all-optical triode light modulation system according to any one of claims 1 to 7; Preferably, the light modulation includes: full optical modulation of optical phase and / or full optical modulation of optical amplitude.

9. A method for modulating light, characterized in that: The modulation method comprises using the all-optical triode light modulation system according to any one of claims 4 to 7 to modulate light, and the modulation method comprises: The pump light output by the pump light source is modulated by the signal generator and then incident on the microring waveguide covered with the van der Waals material through a single-mode optical fiber, and undergoes resonant light absorption to change the refractive index of the van der Waals material; the signal light is coupled to the straight waveguide through the grating coupler, and then coupled to the microring resonator, interacting with the van der Waals material, so that the pump light modulates the signal light and outputs a waveform consistent with the pump light, so as to achieve all-optical modulation of the optical phase and / or all-optical modulation of the amplitude.

10. Use of the all-optical triode light modulation system according to any one of claims 1 to 7 in preparing a device for realizing all-optical modulation of optical phase and / or all-optical modulation of optical amplitude.

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