Optical parametric ultrashort pulse generation device and method based on non-Hermitian phase matching

Abstract

The present invention discloses an optical parametric ultrashort pulse generating device and method based on non-Hermitian phase matching, comprising: a laser emitting pump light to an intensity modulator; the intensity modulator loads a sinusoidal wave driving signal output by an intensity modulation driver based on the pump light to obtain an amplitude modulated driving pump light, and couples the amplitude modulated driving pump light to a non-Hermitian optical structure through a pump light coupling focusing lens; in the non-Hermitian optical structure, the idler light in the parametric gain waveguide is transferred to the parametric dissipative waveguide according to the change of the modulation amplitude, and a parametric pulse signal light is obtained in the parametric gain waveguide, and the parametric pulse signal light is coupled to a wavelength division multiplexer through a signal light coupling focusing lens; the wavelength division multiplexer filters out the residual pump light in the parametric pulse signal light to obtain an optical parametric ultrashort pulse. The present invention directly generates ultrashort pulses by constructing a waveguide coupling structure to realize a gain switching effect near the parity-time symmetry threshold of a non-Hermitian optical system.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrashort pulse generation, and in particular to an optical parametric ultrashort pulse generation device and method based on non-Hermitian phase matching. Background Art

[0002] Ultrashort laser pulse trains play an important role in ultrafast optics and have been widely used in optical frequency combs, high-speed optical communications, and ophthalmic refractive surgery. Traditionally, laser pulse trains in the picosecond and femtosecond range are generated by mode-locking techniques. Whether active or passive mode-locking, an optical resonant cavity that provides periodic gain or loss feedback is essential in order to selectively enhance optical modes with a fixed phase difference and dissipate other optical modes. Therefore, the pulse repetition rate is fundamentally limited by the cavity length, and the repetition rate is difficult to exceed 1 GHz.

[0003] In order to obtain ultrashort pulses with higher repetition rates, several mechanisms have been proposed to generate ultrashort optical pulse trains directly from continuous wave light without the need for optical gain resonators. The relevant technologies can be divided into two categories: one is to use the nonlinear optical effects of materials, such as electro-optic modulation comb, cross-phase modulation, induced modulation instability, adiabatic Raman compression and other technologies, to produce cascaded phase-related sidebands through the nonlinear effects of materials, and to adjust the balance between medium dispersion and third-order polarization tensor to achieve pulse compression; the other is to use linear optical technology to "copy" existing pulse sequences and increase the repetition rate by re-arranging them, such as beating multiple quasi-continuous wave frequency lines and chirped broadband pulse delay replication. Optical parametric amplification technology is another highly promising method for indirectly generating ultrashort pulses. By using laser pulses with high repetition rate and wide time width as signal light, and passing through nonlinear media with continuous or quasi-continuous pump lasers, the spectral width of the signal light is expanded when the phase matching conditions are met, and then a complex compression device is used to compress the signal pulse to obtain pulses with high repetition rate and narrow time width. However, parametric amplification technology usually requires a wide operating bandwidth, but also requires strict phase matching conditions between different frequency components. The latter constraint can be achieved by using a periodic polarization structure or a birefringent crystal. These limiting factors lead to complex optical designs for parametric amplified lasers, which require precise control of the light field in the spatial, temporal, and frequency domains, resulting in bulky and expensive parametric amplification systems. Therefore, how to form stable power oscillations and achieve the generation of ultrashort pulses has become an urgent problem to be solved.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present invention is to provide an optical parametric ultrashort pulse generation device and method based on non-Hermitian phase matching, aiming to solve the technical problem of how to form stable power oscillation and realize the generation of ultrashort pulses.

[0006] To achieve the above object, the present invention provides an optical parametric ultrashort pulse generating device based on non-Hermitian phase matching, wherein the optical parametric ultrashort pulse generating device based on non-Hermitian phase matching comprises a laser, an intensity modulator, an intensity modulation driver, a non-Hermitian optical structure and a wavelength division multiplexer;

[0007] The laser is used to emit pump light to the intensity modulator;

[0008] The intensity modulator is used to load the sinusoidal wave driving signal output by the intensity modulation driver based on the pump light to obtain the amplitude modulated driving pump light, and couple the amplitude modulated driving pump light to the non-Hermitian optical structure through a pump light coupling focusing lens;

[0009] The non-Hermitian optical structure is used to transfer the idler light in the parametric gain waveguide to the parametric dissipative waveguide according to the amplitude modulated driving pump light, obtain the parametric pulse signal light, and couple the parametric pulse signal light to the wavelength division multiplexer through the signal light coupling focusing lens;

[0010] The wavelength division multiplexer is used to filter out the residual pump light in the parametric pulse signal light to obtain optical parametric ultrashort pulses.

[0011] Optionally, the non-Hermitian optical structure comprises a parametric gain waveguide and a parametric dissipative waveguide;

[0012] The parametric gain waveguide is used to generate signal light and idler light through phase matching conditions according to the amplitude modulated driving pump light;

[0013] The parametric gain waveguide is also used to transfer the idler light into the parametric dissipative waveguide and block the signal light to obtain parametric pulse signal light.

[0014] Optionally, the non-Hermitian optical structure further comprises a silicon-based substrate;

[0015] The parametric gain waveguide and the parametric dissipation waveguide are fixed on the silicon-based substrate by a crystal bonding process.

[0016] Optionally, the parametric gain waveguide is also used to determine the wavelength of the driving pump light and the wavelength of the signal light;

[0017] The parametric gain waveguide is also used to determine the polarization period of the periodically excited lithium niobate waveguide according to the wavelength of the driving pump light and the wavelength of the signal light;

[0018] The parametric gain waveguide is also used to determine the phase matching condition according to the polarization period.

[0019] Optionally, the non-Hermitian optical structure further comprises a parametric dissipative modulation driver and a metal electrode;

[0020] The parametric dissipative modulation driver is used to load the generated voltage onto the parametric dissipative waveguide through the metal electrode to modulate the refractive index of the parametric dissipative waveguide to generate an evanescent wave effect;

[0021] The parametric gain waveguide is also used to transfer the idler light into the parametric dissipative waveguide based on the evanescent wave effect according to the parity-time symmetry threshold, so as to block the signal light and obtain parametric pulse signal light.

[0022] Optionally, the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching further includes a dissipative excitation light focusing lens;

[0023] The dissipative excitation light focusing lens is used to transmit the modulated dissipative excitation light to the parametric dissipative waveguide;

[0024] The parametric gain waveguide is also used to transfer the idler light to the parametric dissipative waveguide according to a parity-time symmetry threshold, so that the parametric dissipative waveguide modulates the photon density of the idler light based on the modulated dissipative excitation light to block the signal light and obtain a parametric pulse signal light.

[0025] In addition, to achieve the above-mentioned purpose, the present invention also proposes a method for generating an optical parametric ultrashort pulse based on non-Hermitian phase matching, and the method for generating an optical parametric ultrashort pulse based on non-Hermitian phase matching comprises:

[0026] The laser emits pump light to the intensity modulator;

[0027] The intensity modulator loads the sine wave driving signal output by the intensity modulation driver based on the pump light to obtain an amplitude modulated driving pump light, and couples the amplitude modulated driving pump light to a non-Hermitian optical structure through a pump light coupling focusing lens;

[0028] The non-Hermitian optical structure transfers the idler light in the parametric gain waveguide to the parametric dissipative waveguide according to the amplitude modulated driving pump light to obtain a parametric pulse signal light, and couples the parametric pulse signal light to a wavelength division multiplexer through a signal light coupling focusing lens;

[0029] The wavelength division multiplexer filters out the residual pump light in the parametric pulse signal light to obtain an optical parametric ultrashort pulse.

[0030] The present invention firstly emits pump light to the intensity modulator through a laser, and then the intensity modulator loads a sinusoidal wave driving signal output by an intensity modulation driver based on the pump light to obtain an amplitude-modulated driving pump light, and couples the amplitude-modulated driving pump light to a non-Hermitian optical structure through a pump light coupling focusing lens, and then in the non-Hermitian optical structure, the idler light in the parametric gain waveguide is transferred to the parametric dissipative waveguide according to the change of the modulation amplitude, and a parametric pulse signal light is obtained in the parametric gain waveguide, and the parametric pulse signal light is coupled to a wavelength division multiplexer through a signal light coupling focusing lens, and finally the wavelength division multiplexer filters out the residual pump light in the parametric pulse signal light to obtain an optical parametric ultrashort pulse. The present invention directly generates an ultrashort pulse train by constructing a stable waveguide coupling structure based on the non-Hermitian optical structure to realize the gain switching effect near the parity-time symmetry threshold of the non-Hermitian optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of a specific implementation method of the first embodiment of the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching of the present invention;

[0032] Figure 2 It is a schematic diagram showing the principle of ultrashort pulse generation according to the first embodiment of the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching of the present invention;

[0033] Figure 3 It is a structural block diagram of the first embodiment of the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching of the present invention;

[0034] Figure 4 It is a schematic diagram of a single-pump structure implementation scheme of the first embodiment of the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching of the present invention;

[0035] Figure 5 It is a schematic diagram of a pump and idler light synchronization structure implementation scheme of the first embodiment of the optical parametric ultrashort pulse generator based on non-Hermitian phase matching of the present invention;

[0036] Figure 6 It is a flow chart of the first embodiment of the optical parametric ultrashort pulse generation method based on non-Hermitian phase matching of the present invention.

[0037] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0039] Reference Figure 1 , Figure 1It is a schematic diagram of a specific implementation method of the first embodiment of the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching of the present invention.

[0040] like Figure 1 As shown, the optical parametric ultrashort pulse generating device based on non-Hermitian phase matching may include: a pump light coupling focusing lens 101, a dissipative excitation light focusing lens 102, a parametric gain waveguide 103, a parametric dissipative waveguide 104, a metal electrode 105, a silicon-based substrate 106, and a signal light coupling focusing lens 107.

[0041] It should be noted that the working principle of the non-Hermitian optical structure is: the pump light coupling focusing lens 101 inputs the amplitude-modulated driving pump light, and couples the amplitude-modulated driving pump light to the parametric gain waveguide 103 to provide the pump laser required to generate ultrashort; the dissipative excitation light focusing lens 102 inputs the dissipative excitation light with both phase and amplitude modulated to the parametric dissipative waveguide 104, and adjusts the energy intensity and phase change of the idler light to keep the parametric gain near the parity time switch threshold.

[0042] It should be understood that when the pump light amplitude reaches the signal light generation threshold, idler light will be generated at the same time. In the absence of dissipative excitation, the signal light will be in a continuous working mode for a long time, and will only be affected by the pump light intensity, and will not be able to generate ultrashort pulses. The introduction of dissipative excitation adjusts the working state of the parametric dissipative waveguide 104. When the signal light is generated, the idler light in the parametric gain waveguide 103 is introduced into the parametric dissipative waveguide 104 through the photon dissipation process, breaking the inherent balance, generating an instantaneous switching effect, cutting off the parametric gain process, and only generating an instantaneous pulse response at the pump gain threshold.

[0043] It should be understood that the parametric gain waveguide is a periodically poled lithium niobate waveguide, and the polarization period depends on the wavelength of the input pump light and the wavelength of the signal light. The parametric dissipative waveguide 104 is a lithium niobate waveguide, and does not require periodic excitation processing.

[0044] Furthermore, when no dissipative excitation light is introduced, a high-speed modulation voltage is introduced through the metal electrode 105 to adjust the refractive index change of the parametric dissipative waveguide 104, control the generation and dissipation process of the idler light, and the parametric gain is near the parity time switch threshold.

[0045] It should also be noted that the parametric gain waveguide 103 and the parametric dissipative waveguide 104 are fixed on the silicon-based substrate 106 through a crystal bonding process, and the light generated after the parametric transformation process is coupled out through the signal light coupling focusing lens 107 .

[0046] Those skilled in the art will understand that Figure 1The structure shown in the figure does not constitute a limitation on the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching, and may include more or less components than those shown in the figure, or a combination of certain components, or a different arrangement of components.

[0047] In this embodiment, reference Figure 2 , Figure 2 The schematic diagram of the principle of ultrashort pulse generation of the first embodiment of the optical parametric ultrashort pulse generator based on non-Hermitian phase matching of the present invention is shown in the figure. The continuous optical signal after amplitude modulation is expressed as a sine wave in the time domain. After amplification, the peak value of the continuous optical signal is controlled to exceed the parity-time symmetry threshold value, and is injected into the parametric gain waveguide 103 as the amplitude-modulated driving pump light 201 to generate a parametric amplification signal. When the amplitude of the amplitude-modulated driving pump light 201 exceeds the parity-time symmetry threshold value 203, a parametric oscillation signal is generated due to exceeding the parity-time symmetry threshold value. At the same time, due to the presence of the parametric dissipative waveguide 104, idle photons are continuously transferred, so it is necessary to maintain the parametric pulse signal light 202 generated by the parametric process in a high peak state. When the intensity of the modulated sine wave signal decreases and is lower than the parity-time symmetry threshold value 203, the parametric dissipative waveguide 104 transfers idle photons, blocks the generation of the signal light, forms a rapid shutdown, and obtains an ultrashort pulse, i.e., a parametric pulse signal light 202.

[0048] It should be noted that based on Figure 1 and Figure 2 Based on the principle of the present invention, an embodiment of the present invention provides an optical parametric ultrashort pulse generation device based on non-Hermitian phase matching, referring to Figure 3 , Figure 3 It is a structural block diagram of the first embodiment of the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching of the present invention.

[0049] In this embodiment, the optical parametric ultrashort pulse generating device based on non-Hermitian phase matching includes a laser 1001, an intensity modulator 1002, an intensity modulation driver 1003, a non-Hermitian optical structure 1004 and a wavelength division multiplexer 1005;

[0050] The laser 1001 is used to emit pump light to the intensity modulator 1002 .

[0051] It should be understood that the laser 1001 is Figure 4 Single frequency laser 301 or Figure 5 The single frequency laser 401 and the intensity modulator 1002 are Figure 4 Medium intensity modulator 302 or Figure 5 Medium intensity modulator 402.

[0052] It should also be noted that the single-frequency laser 301 is connected to the intensity modulator 302 to provide the pump light required for optical parametric amplification, and the light source is a single-frequency narrow-linewidth light source to ensure that the frequency characteristics of the light field after intensity modulation are still single-frequency lasers. The single-frequency laser 301 is used to ensure that the frequency characteristics of the light field after intensity modulation do not generate additional intensity modulation caused by the beat frequency of multiple longitudinal modes.

[0053] The intensity modulator 1002 is used to obtain amplitude-modulated driving pump light by loading the sinusoidal wave driving signal output by the intensity modulation driver based on the pump light, and couple the amplitude-modulated driving pump light to the non-Hermitian optical structure 1003 through a pump light coupling focusing lens.

[0054] In this embodiment, the input end of the intensity modulator is connected to the intensity modulation driver, and the output end of the intensity modulator is connected to the parametric dissipative waveguide of the non-Hermitian optical structure.

[0055] The intensity modulation driver 1003 is Figure 4 Medium intensity modulation driver 303 or Figure 5 Medium intensity modulation driver 403; non-Hermitian optical structure 1004 is Figure 4 Non-Hermitian Optical Structures 304 or Figure 5 Non-Hermitian optical structures405.

[0056] The intensity modulator driver generates a sinusoidal wave driving signal, and the modulation intensity of the sinusoidal wave is affected by adjusting the modulation depth. The phase and chirp of the sinusoidal wave can be adjusted in frequency to match the phase relationship required by the optical parametric generation process of the non-Hermitian optical structure.

[0057] It should also be noted that the pump light coupling focusing lens is an optical focusing lens that can inject amplitude modulated driving pump light into the parametric gain waveguide. The parametric gain waveguide is a waveguide made of periodically polarized crystals. The cross-sectional diameter meets the fundamental transverse mode transmission conditions, but the polarization period depends on the pump laser wavelength and the signal light wavelength.

[0058] The non-Hermitian optical structure 1004 is used to transfer the idler light in the parametric gain waveguide to the parametric dissipative waveguide according to the amplitude modulated driving pump light, obtain the parametric pulse signal light, and couple the parametric pulse signal light into the wavelength division multiplexer 1005 through the signal light coupling focusing lens.

[0059] Furthermore, the non-Hermitian optical structure includes a parametric gain waveguide, a parametric dissipative waveguide and a silicon-based substrate; the parametric gain waveguide and the parametric dissipative waveguide are fixed on the silicon-based substrate by a crystal bonding process. The silicon-based substrate is made of silicon dioxide material and is used to carry two waveguides.

[0060] The parametric dissipative waveguide is a waveguide made of crystal, and its transmission mode can be a fundamental transverse mode or a high-order mode, and the distance between the two waveguides is twice the wavelength of the driving signal.

[0061] In this embodiment, the parametric gain waveguide determines the wavelength of the driving pump light and the wavelength of the signal light; the polarization period of the periodically excited lithium niobate waveguide is determined according to the wavelength of the driving pump light and the wavelength of the signal light; the parametric gain waveguide determines the phase matching condition according to the polarization period; the parametric gain waveguide generates the signal light and the idler light according to the phase matching condition according to the amplitude modulated driving pump light.

[0062] In the specific implementation, refer to Figure 4 , Figure 4 This is a schematic diagram of a single-pump structure implementation scheme of the first embodiment of the optical parametric ultrashort pulse generator based on non-Hermitian phase matching of the present invention. The non-Hermitian optical structure also includes a parametric dissipative modulation driver and a metal electrode. The parametric dissipative modulation driver loads the generated voltage onto the parametric dissipative waveguide through the metal electrode to modulate the refractive index of the parametric dissipative waveguide to produce an evanescent wave effect. The parametric gain waveguide transfers the idler light to the parametric dissipative waveguide based on the evanescent wave effect according to the parity-time symmetry threshold (i.e., when the intensity of the sinusoidal wave signal modulated by the amplitude-modulated driving pump light 201 decreases and is lower than the parity-time symmetry threshold 203) to block the generation of continuous signal light, form a rapid shutdown, and obtain parametric pulse signal light.

[0063] Metal electrodes are made of metal and are used to load the modulated signal parameters onto the dissipative waveguide. Different voltage values ​​can change the refractive index of the crystal.

[0064] Depend on Figure 4 It can be seen that the pump light passing through the modulator is coupled to the parametric gain waveguide 103 of the non-Hermitian optical structure 304, and a parametric conversion process occurs under the action of the parametric gain and parity time switch. At the same time, the voltage generated by the parametric dissipative modulation driver 305 is loaded on the parametric dissipative waveguide 104 through the metal electrode 105. Under the action of the voltage signal, the refractive index of the parametric dissipative waveguide 104 is modulated to control the dissipation process to achieve a fast switching effect near the threshold.

[0065] The parametric dissipative modulation driver can output a voltage signal with adjustable amplitude and phase, which is loaded on the dissipative waveguide.

[0066] In the specific implementation, refer to Figure 5 , Figure 5This is a schematic diagram of an implementation scheme of the pump and idler light synchronization structure of the first embodiment of the optical parametric ultrashort pulse generator based on non-Hermitian phase matching of the present invention. The optical parametric ultrashort pulse generator based on non-Hermitian phase matching also includes a dissipative excitation light focusing lens; the dissipative excitation light focusing lens transmits the modulated dissipative excitation light to the parametric dissipative waveguide; the parametric gain waveguide transfers the idler light to the parametric dissipative waveguide according to the parity-time symmetry threshold (i.e., when the intensity of the sinusoidal wave signal modulated by the amplitude-modulated driving pump light 201 decreases and is lower than the parity-time symmetry threshold 203), so that the parametric dissipative waveguide modulates the photon density of the idler light based on the modulated dissipative excitation light to block the continuous signal light and obtain the parametric pulse signal light.

[0067] Depend on Figure 5 It can be seen that the pump light through the modulator is coupled to the parametric gain waveguide 103 of the non-Hermitian optical structure 405, and a parametric conversion process occurs under the action of the parametric gain and parity time switch. At the same time, the idler light 404 is modulated to generate an optical pulse signal with amplitude and phase adjusted at the same time, and the modulated dissipative excitation light is injected into the parametric dissipative waveguide 104 through the dissipative excitation light focusing lens. When the intensity of the sine wave signal modulated by the amplitude modulated driving pump light 201 decreases and is lower than the parity time symmetry threshold 203, the idler light is transferred to the parametric dissipative waveguide, and the photon density of the idler light in the parametric dissipative waveguide 104 is modulated under the action of the light intensity and phase of the idler light, and the dissipation process is controlled to achieve the generation of a fast switching effect near the threshold.

[0068] The parametric gain waveguide is connected to the intensity modulator, the optical input end of the parametric dissipative waveguide is connected to the modulated idler light, and the modulated idler light is connected to the parametric dissipative waveguide in the non-Hermitian optical structure, and its wavelength matches the wavelength of the idler light generated in the optical parametric process driven by the pump light.

[0069] In this embodiment, the parametric pulse signal light is coupled to the wavelength division multiplexer 1005 through the signal light coupling focusing lens. The wavelength division multiplexer 1005 is Figure 4 MWDM 306 or Figure 5 The medium wavelength division multiplexer 406, the signal light coupling focusing lens is an optical focusing lens, which can couple the generated signal light into the transmission optical fiber.

[0070] It should also be noted that by periodically activating the lithium niobate waveguide structure bonded to the silicon-based material, designing the coupling effect and dissipative structure of the waveguide, and realizing the optical structure with spatially distributed loss and gain, parity-time symmetry is established, that is, a directional coupler of two waveguides with spatially distributed gain and loss parts. When the gain or loss increases, the symmetry of the mode will be destroyed, and the mode with the strongest gain (or the smallest loss) will dominate. The introduction of this switching effect can establish a fast switching modulation effect on the pump pulse, and modulate the fast-band pulses that are simultaneously modulated in the time domain and the frequency domain into ultrashort pulse outputs, and no longer rely on complex mode-locking mechanisms or external modulation to obtain ultrashort pulse sequences with high repetition rates.

[0071] The wavelength division multiplexer 1005 is used to filter out the residual pump light in the parametric pulse signal light to obtain optical parametric ultrashort pulses.

[0072] The wavelength division multiplexer is connected to the output end of the parametric gain waveguide in the non-Hermitian optical structure, and can separate the pump laser and the signal light according to the wavelength.

[0073] In a specific implementation, the output end of the parametric gain waveguide 103 of the non-Hermitian optical structure 304 is connected to the wavelength division multiplexer 306 to filter out residual pump light; or the output end of the parametric gain waveguide 103 of the non-Hermitian optical structure 405 is connected to the wavelength division multiplexer 406 to filter out residual pump light; thereby obtaining an optical parametric ultrashort pulse.

[0074] In this embodiment, firstly, a pump light is emitted to the intensity modulator by a laser, and then the intensity modulator loads a sinusoidal wave driving signal output by an intensity modulation driver based on the pump light to obtain an amplitude modulated driving pump light, and the amplitude modulated driving pump light is coupled to a non-Hermitian optical structure through a pump light coupling focusing lens, and then in the non-Hermitian optical structure, the idler light in the parametric gain waveguide is transferred to the parametric dissipative waveguide according to the change of the modulation amplitude, and a parametric pulse signal light is obtained in the parametric gain waveguide, and the parametric pulse signal light is coupled to a wavelength division multiplexer through a signal light coupling focusing lens, and finally the wavelength division multiplexer filters out the residual pump light in the parametric pulse signal light to obtain an optical parametric ultrashort pulse. The present invention constructs a stable waveguide coupling structure through a non-Hermitian optical structure, and realizes a gain switching effect near the parity-time symmetry threshold of a non-Hermitian optical system to directly generate an ultrashort pulse train.

[0075] Reference Figure 6 , Figure 6 It is a flow chart of the first embodiment of the optical parametric ultrashort pulse generation method based on non-Hermitian phase matching of the present invention.

[0076] like Figure 6 As shown, the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching proposed in an embodiment of the present invention includes:

[0077] Step S10: The laser emits pump light to the intensity modulator;

[0078] Step S20: the intensity modulator loads the sinusoidal wave driving signal output by the intensity modulation driver based on the pump light to obtain an amplitude modulated driving pump light, and couples the amplitude modulated driving pump light to a non-Hermitian optical structure through a pump light coupling focusing lens;

[0079] Step S30: the non-Hermitian optical structure transfers the idler light in the parametric gain waveguide to the parametric dissipative waveguide according to the amplitude modulated driving pump light to obtain a parametric pulse signal light, and couples the parametric pulse signal light to a wavelength division multiplexer through a signal light coupling focusing lens;

[0080] Step S40: the wavelength division multiplexer filters out residual pump light in the parametric pulse signal light to obtain an optical parametric ultrashort pulse.

[0081] Other embodiments or specific implementations of the optical parametric ultrashort pulse generation device based on non-Hermitian phase matching of the present invention can refer to the above-mentioned method embodiments, which will not be described in detail here.

[0082] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0083] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0084] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory / random access memory, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0085] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An optical parametric ultrashort pulse generator based on non-Hermitian phase matching, characterized in that: The optical parametric ultrashort pulse generating device based on non-Hermitian phase matching comprises a laser, an intensity modulator, an intensity modulation driver, a non-Hermitian optical structure and a wavelength division multiplexer; The laser is used to emit pump light to the intensity modulator; The intensity modulator is used to load the sinusoidal wave driving signal output by the intensity modulation driver based on the pump light to obtain the amplitude modulated driving pump light, and couple the amplitude modulated driving pump light to the non-Hermitian optical structure through a pump light coupling focusing lens; The non-Hermitian optical structure is used to transfer the idler light in the parametric gain waveguide to the parametric dissipative waveguide according to the amplitude modulated driving pump light, obtain the parametric pulse signal light, and couple the parametric pulse signal light to the wavelength division multiplexer through the signal light coupling focusing lens; The wavelength division multiplexer is used to filter out the residual pump light in the parametric pulse signal light to obtain an optical parametric ultrashort pulse; Wherein, the non-Hermitian optical structure includes a parametric gain waveguide and a parametric dissipative waveguide; The parametric gain waveguide is used to generate signal light and idler light through phase matching conditions according to the amplitude modulated driving pump light; The non-Hermitian optical structure also includes a parametric dissipative modulation driver and a metal electrode; The parametric dissipative modulation driver is used to load the generated voltage onto the parametric dissipative waveguide through the metal electrode to modulate the refractive index of the parametric dissipative waveguide to generate an evanescent wave effect; The parametric gain waveguide is further used to transfer the idler light into the parametric dissipative waveguide according to the parity-time symmetry threshold based on the evanescent wave effect, so as to block the signal light and obtain the parametric pulse signal light; The optical parametric ultrashort pulse generation device based on non-Hermitian phase matching also includes a dissipative excitation light focusing lens; The dissipative excitation light focusing lens is used to transmit the modulated dissipative excitation light to the parametric dissipative waveguide; The parametric gain waveguide is also used to transfer the idler light to the parametric dissipative waveguide according to a parity-time symmetry threshold, so that the parametric dissipative waveguide modulates the photon density of the idler light based on the modulated dissipative excitation light to block the signal light and obtain a parametric pulse signal light.

2. The device according to claim 1, characterized in that The non-Hermitian optical structure also includes a silicon-based substrate; The parametric gain waveguide and the parametric dissipation waveguide are fixed on the silicon-based substrate by a crystal bonding process.

3. The device according to claim 2, characterized in that The parametric gain waveguide is also used to determine the wavelength of the driving pump light and the wavelength of the signal light, wherein the parametric gain waveguide is a periodically poled lithium niobate waveguide; The parametric gain waveguide is further used to determine the polarization period of the periodically polarized lithium niobate waveguide according to the wavelength of the driving pump light and the wavelength of the signal light; The parametric gain waveguide is also used to determine the phase matching condition according to the polarization period.

4. A method for generating optical parametric ultrashort pulses based on non-Hermitian phase matching, characterized in that: The optical parametric ultrashort pulse generation method based on non-Hermitian phase matching comprises the following steps: The laser emits pump light to the intensity modulator; The intensity modulator obtains an amplitude-modulated driving pump light based on the sinusoidal wave driving signal output by the intensity modulation driver loaded on the pump light, and couples the amplitude-modulated driving pump light to the non-Hermitian optical structure through a pump light coupling focusing lens; The non-Hermitian optical structure transfers the idler light in the parametric gain waveguide to the parametric dissipative waveguide according to the amplitude modulated driving pump light to obtain a parametric pulse signal light, and couples the parametric pulse signal light to a wavelength division multiplexer through a signal light coupling focusing lens; The wavelength division multiplexer filters out the residual pump light in the parametric pulse signal light to obtain an optical parametric ultrashort pulse; Wherein, the non-Hermitian optical structure includes a parametric gain waveguide and a parametric dissipative waveguide; The parametric gain waveguide generates signal light and idler light according to the amplitude modulated driving pump light through phase matching conditions; The non-Hermitian optical structure also includes a parametric dissipative modulation driver and a metal electrode; The parametric dissipative modulation driver applies the generated voltage to the parametric dissipative waveguide through the metal electrode to modulate the refractive index of the parametric dissipative waveguide to generate an evanescent wave effect; The parametric gain waveguide transfers the idler light into the parametric dissipative waveguide based on the evanescent wave effect according to the parity-time symmetry threshold, so as to block the signal light and obtain a parametric pulse signal light; The optical parametric ultrashort pulse generation method based on non-Hermitian phase matching also includes: The dissipative excitation light focusing lens transmits the modulated dissipative excitation light to the parametric dissipative waveguide; The parametric gain waveguide transfers the idler light to the parametric dissipative waveguide according to a parity-time symmetry threshold, so that the parametric dissipative waveguide modulates the photon density of the idler light based on the modulated dissipative excitation light to block the signal light and obtain a parametric pulse signal light.

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