138 results about "Coupling loss" patented technology

The invention discloses a spot-size converter (SSC) and a high-power external cavity laser chip, the external cavity laser chip comprises a wide-ridge gain chip and a passive external cavity chip, one end of the wide-ridge gain chip is plated with a high-reflection film as a reflection end, and the other end of the wide-ridge gain chip is plated with an antireflection film to realize low reflection; and efficient coupling of the fundamental mode of the wide-ridge gain chip with the size far larger than that of the single-transverse-mode waveguide and the small-size single-mode waveguide is realized by integrating the SSC. The SSC converts a large-size mode field and a small-size mode field mutually and effectively reduces optical coupling loss, mode selection and output wavelength adjustability are achieved by adjusting the longitudinal mode phase shifter and the micro-ring filter, part of power is fed back to the wide-ridge gain chip to construct external cavity resonance, and high-power output is achieved. According to the SSC, the device size can be remarkably reduced, a wide-ridge gain chip and an inter-chip hybrid integration process are compatible, and the tuning flexibility, the integration level and the overall stability of the laser are further improved while high-power output is kept.

The invention relates to the technical field of connector regulation and control, and discloses an efficient energy storage connector dynamic regulation and control system based on a nonlinear coupling mechanism. The system comprises an establishment module used for establishing an energy storage connector system model based on a voltage signal and a current signal of an energy storage connector; the disturbance identification module is used for performing nonlinear coupling disturbance identification on the energy transmission process according to the energy storage connector system model to obtain an additional coupling loss component, a dynamic impedance drift component and a phase coupling offset component; the dynamic observation module is used for performing weighted analysis through a nonlinear coupling dynamic observer to obtain a coupling mechanism observation result; and the generation module is used for generating an energy transmission path regulation and control instruction containing the conduction angle compensation amount and the phase synchronization compensation amount based on the coupling mechanism observation result. According to the invention, stable operation can be realized under complex working conditions such as load abrupt change and coupling impedance fluctuation, and the transmission efficiency is maximized.

The invention relates to the technical field of optical fiber connection, and provides an optical fiber connection structure and method, and the structure comprises a first to-be-connected optical fiber (1), a second to-be-connected optical fiber (2), and a hollow connecting pipe (3). The connecting end of the first optical fiber (1) to be connected extends into the hollow part of the hollow connecting pipe (3) from the first end of the hollow connecting pipe (3), and the connecting end of the second optical fiber (2) to be connected extends into the hollow part of the hollow connecting pipe (3) from the second end of the hollow connecting pipe (3); wherein if the light beam output by the connection end of the first to-be-connected optical fiber (1) is matched with the mode field of the connection end of the second to-be-connected optical fiber (2), the connection end of the first to-be-connected optical fiber (1) is in contact with the connection end of the second to-be-connected optical fiber (2); otherwise, an air gap with the length being the preset distance # imgabs0 # exists between the connection end of the first optical fiber to be connected (1) and the connection end of the second optical fiber to be connected (2), and the spot size of the emergent light of the first optical fiber to be connected is matched with the mode field of the second optical fiber to be connected after passing through the air gap with the preset distance # imgabs1 #; by adopting the connection structure and the connection method, the back reflection can be reduced while the coupling loss is reduced.

The invention discloses a segmented slot design method and system of a leaky coaxial cable and a storage medium. The method comprises the following steps: constructing a performance fitting formula of the leaky coaxial cable according to segmented slot state parameters; and calculating the coupling loss of each slotted hole segmented structure on the leaky coaxial cable according to a performance fitting formula and a system loss threshold. And calculating corresponding segmented slot state parameters and transmission attenuation according to the coupling loss of each slot segmented structure. And calculating an expected size parameter of the leaky coaxial cable according to the segmented slotted hole state parameter and the transmission attenuation of each slotted hole segmented structure. According to the leaky coaxial cable, the maximum value and the minimum value of the system loss are limited in a relatively small expected value, so that the system loss curve tends to be in a uniform and horizontal state, and the system loss of the leaky coaxial cable reaches a relatively good state.

The invention discloses a hollow-core fiber fusion coupling loss evaluation method and device, and the method comprises the steps: firstly collecting a cross-section image of a first hollow-core fiber fusion end, enabling laser to pass through the cross-section image, then collecting a light field distribution image of emergent light of the fusion end, and carrying out the fitting, thereby obtaining a nested tube circumcircle and a light field fitting regular polygon; welding the two hollow-core optical fibers, and acquiring a cross-section image of a non-welding end of the second hollow-core optical fiber and a light field distribution image after the laser is introduced to complete the same fitting; and finally, inputting the related geometric parameters before and after welding into a preset evaluation model to obtain welding loss. According to the invention, accurate and real-time evaluation of the welding loss is realized.

A device for connecting RF signal between a first and a second microwave element, the device including coupling interfaces, wherein the device is arranged to facilitate said connection with less than 2 dB coupling loss between said interfaces at a first frequency. The device is a connector arrangement that includes a first and a second layered member structured to be mated with a fixturing member of the device, and said members being isolated by a coupling membrane, wherein the first layered member includes a first mating aperture, arranged to receive the RF signal from the first microwave element via first of the coupling interfaces, and the second layered member includes a second mating aperture, arranged to connect the received RF signal to the second microwave element via second of the coupling interfaces.

The invention relates to the technical field of image processing, and provides an infrared weak and small target detection method which comprises the following steps: acquiring an infrared image to be detected; and inputting a to-be-detected infrared image into the infrared weak and small target detection model based on YOLOV8 improvement, and obtaining an infrared weak and small target detection result of the to-be-detected infrared image. The infrared weak and small target detection model comprises an improved backbone network based on a channel transposition attention mechanism, a rapid fusion C2f module and a lightweight spatial pyramid pooling module, an improved neck network based on an infrared weak and small target detection module, and an improved detection head network based on an infrared weak and small target detection head and three lightweight detection heads. The infrared weak and small target detection model is obtained based on training of a super-division coupling loss function, and the super-division coupling loss function is calculated and determined according to the low-level features and the high-level features extracted by the backbone network and the super-division coupling network. By using the infrared weak and small target detection model based on YOLOV8 improvement, the precision and efficiency of infrared weak and small target detection are improved.

The invention discloses an all-fiber structure pulse laser based on a superfine single-crystal fiber and a preparation method thereof. The all-fiber structure pulse laser comprises a gain single-crystal fiber and a pulse modulation single-crystal fiber, and the gain single-crystal fiber and the pulse modulation single-crystal fiber form a superfine single-crystal fiber heterogeneous bonding structure through thermocompression bonding; the gain single-crystal optical fiber serves as a laser gain medium, the pulse modulation single-crystal optical fiber serves as a saturable absorber, the gain single-crystal optical fiber is provided with a high-reflection grating, the high-reflection grating and an oblique-angle low-reflection end arranged at the tail end of the pulse modulation single-crystal optical fiber form a resonant cavity, and pump light is input into the gain single-crystal optical fiber and enters the resonant cavity through the high-reflection grating. And the oblique-angle low-reflection end outputs pulse laser. The gain section and the modulation section are fused into an integrated structure through the superfine single crystal optical fiber bonding technology, the high-reflection grating is inscribed through the femtosecond laser direct writing technology, low-reflection-mirror oblique angle processing is carried out at the output end, space coupling loss is eliminated, and all-optical-fiber monolithic integration is achieved.

The invention provides a preparation method of a silicon nitride waveguide structure, and the method comprises the following steps: providing a substrate, and forming a silicon nitride waveguide layer on the surface of the substrate; sequentially forming a first silicon oxide layer, a polycrystalline silicon layer and a second silicon oxide layer on the surface of the silicon nitride waveguide layer to form a hard mask layer; performing patterning processing on the hard mask layer to form an etching hard mask; etching the silicon nitride waveguide layer to form a target silicon nitride waveguide structure; and removing the residual etching hard mask. According to the invention, based on the hard masks of the three-layer structure and by optimizing the thickness of each layer of hard mask film, the etching size deviation can be controlled within an extremely small range, the etched waveguide structure is smooth in side wall and good in perpendicularity, and the coupling loss of a silicon nitride end face coupler and the transmission loss of a silicon nitride waveguide can be effectively reduced.

The invention discloses an on-chip active reconfigurable filter passband flatness optimization method and circuit, and belongs to the field of integrated circuits and wireless communication. The filter comprises a coupling element, negative resistance compensation units are connected to the two ends of the coupling element and connected with the coupling element in parallel, and the coupling element comprises a coupling inductor or a coupling capacitor. The invention provides a passband flatness method based on active coupling compensation by deeply analyzing the passband flatness distortion reason of the on-chip coupling filter, and designs a detailed controllable negative resistance unit to compensate the coupling (inductive coupling) loss of the base transformer, thereby greatly reducing the in-band insertion loss variation of the filter, and improving the filter performance. And the amplitude consistency of the signal after passing through the filter is improved.

The application provides an optical coupler applied to the field of optical communication. The optical coupler comprises a buried layer, a support layer, a waveguide layer and an upper cladding layer. In the height direction, the support layer is between the buried layer and the waveguide layer. The waveguide layer is between the support layer and the upper cladding layer. In the width direction, the waveguide layer and the support layer are inside the upper cladding layer. The materials of the waveguide layer and the support layer are different. In the application, the support layer is inside the upper cladding layer. Therefore, the upper cladding layer is on both sides of the support layer. The energy of the optical signal can be dispersed on both sides of the support layer, so that the degree of uneven energy distribution near the center of the waveguide layer is reduced, and the coupling loss of the optical coupler is reduced.

The present invention relates to the technical field of optical communication. Disclosed are a coupling method and coupling structure for a hollow optical fiber, and an optical fiber connector. The method of the present invention comprises the steps of: welding a first optical fiber with a first end surface of a bridge fiber, processing a second end surface of the bridge fiber into an inclined surface at a preset angle to serve as a coupling end surface, and fixing the overall structure obtained by welding the first optical fiber with the bridge fiber in a first sleeve to obtain a first intermediate; fixing the hollow optical fiber in a second sleeve to obtain a second intermediate; and clamping and fixing the first intermediate and the second intermediate by using an optical fiber coupling platform, adjusting the position of the first intermediate and / or the second intermediate, synchronously performing a powder test, and encapsulating and fixing coupling points when the coupling loss is at the minimum, thereby achieving the coupling of the hollow optical fiber and the first optical fiber. The present invention expands the application scenarios, and reduces the coupling loss and return loss.

The invention belongs to the technical field of terahertz, relates to terahertz communication, and particularly discloses a quasi-optical resonant cavity and a terahertz pulse compression system. According to the invention, the pulse generation module and the coupling compensation module are connected in parallel and are connected to the common reflector through the common coupler, so that function decoupling is realized. In a pulse compression stage, the common coupler introduces an incident terahertz wave beam into two optical paths, and destructive interference occurs between two paths of leakage signals by adjusting the coupling compensation module, so that zero coupling loss is realized, and the problem of large energy loss is solved. Meanwhile, the pulse generation module can independently adjust the optical path of the pulse generation module to control the pulse width, and the adjustment process does not affect the optimized interference condition, so that the high robustness of adjustment is ensured. In the output stage, energy is released by switching the state of the common coupler. Compared with the prior art, low-loss accumulation and robust pulse width continuous adjustment are realized at the same time, so that the terahertz pulse compression effect is remarkably improved.

The invention relates to the technical field of capacitor testing, in particular to a full-working-condition equivalent testing system and method for a capacitor for direct-current power transmission. The method comprises the following steps: applying a single-frequency AC component to a capacitor, and obtaining an inherent single-frequency loss baseline of the capacitor under single-frequency excitation; determining harmonic coupling loss according to the single-frequency loss baseline; strong interaction harmonic pairs are screened out according to harmonic coupling loss, and additional loss is measured again under the condition that controlled thermal gradient disturbance and mechanical resonance excitation are applied to calibrate a thermal field gain factor and a mechanical vibration gain factor; and based on the thermal field gain factor and the mechanical vibration gain factor, evaluating the total loss of the full-working-condition test to obtain full-working-condition test data. According to the method, accurate evaluation and contribution degree decomposition of the loss characteristics of the capacitor under the multi-physical-field full working condition are realized.

The invention relates to the technical field of coupling device design and manufacturing, in particular to an interlayer coupler with a multi-layer waveguide structure and a manufacturing method of the interlayer coupler. The interlayer coupler comprises at least three layers of stacked waveguide structures, the lowermost waveguide structure is a silicon waveguide, and the refractive indexes of the waveguide structures are gradually reduced from bottom to top. The refractive index of each layer of waveguide structure which is arranged in a laminated manner is set to be gradually reduced, so that optical signals can be more stably transited when being transmitted among different waveguide layers, the reflection and scattering phenomena caused by sudden change of the refractive index are effectively avoided, optical loss caused by sudden change of the refractive index is greatly reduced, and the optical transmission efficiency is improved. The coupling loss of the interlayer coupler is significantly reduced, and the optical transmission efficiency of the interlayer coupler is greatly improved. And the mode field matching degree can be effectively improved, the problem of mode field mismatching is solved, and the coupling loss of the light field is further reduced.

The utility model relates to a lithium niobate end face coupler, including substrate: the lower cladding layer, covering layer are sequentially equipped from below to above on the substrate, the upper end of lower cladding layer is sequentially equipped with first flat plate structure and first waveguide structure from below to above, and first waveguide structure is located the upside of bottom layer first flat plate structure, and first flat plate structure and first waveguide structure are located in covering layer, and first flat plate structure includes first flat plate layer and the second waveguide structure located the upside of first flat plate layer, wherein, the thickness of first flat plate layer is 1nm 30nm, and the thickness of first flat plate layer is less than the thickness of second waveguide structure, the utility model discloses a lithium niobate end face coupler adds first flat plate layer, significantly reduces the coupling loss of thin film lithium niobate end face coupler, is favorable to the mass production of lithium niobate end face coupler.

The application relates to the technical field of laser lighting, in particular to a non-electric manual laser switch and a using method thereof, and aims to solve the problems of poor explosion-proof performance, high laser leakage risk, large coupling loss and stray light interference of an existing laser switch. The switch is connected in series between a light fiber at a light emitting end of a laser and a light fiber at a receiving end of a lighting system, and comprises a manual operating mechanism, a double-lens assembly, a high-precision positioning pin, a light cone assembly, a stray light protection piece and a shell. The switch realizes light path on-off through pure mechanical manual operation. When the switch is turned on, the double lens is accurately aligned through the positioning pin, and laser is coupled and transmitted with low loss. When the switch is turned off, the light cone absorbs laser on the laser side, and the stray light protection piece blocks external stray light. The switch does not have any electrical components, meets the Exd IIC T6 explosion-proof grade, has a coupling loss of less than or equal to 0.2 dB, has laser leakage of less than or equal to 0.01 mW when turned off, is suitable for environments of-40 DEG C to 85 DEG C, and is suitable for explosion-proof scenes such as natural gas pipe corridors and chemical industrial parks. The switch is convenient to operate and has a long service life.

This invention belongs to the field of optical component mounting technology, specifically a real-time coaxial optical coupling loss detection and alignment system for prisms and lens arrays. It includes an automatic loading and unloading module for automatically loading the substrate, prisms, and lens arrays, and automatically sorting and unloading qualified and unqualified products. By adopting a technical solution that uses the real-time coaxial optical coupling loss detection value as the sole criterion for final alignment of the lens array, combined with a graded alignment strategy of visual coarse alignment and coaxial optical fine alignment, it solves the common industry pain point of existing pure visual alignment and passive alignment technologies that separate physical dimensional accuracy from optical performance. This results in the inability to compensate for manufacturing errors such as uneven refractive index and surface flatness deviations within optical components, leading to substandard optical performance despite meeting physical accuracy standards and low yield rates in mass production. By using dimensional and angular tolerances only as auxiliary constraints, it directly locks the global minimum coupling loss point, improving the consistency and stability of the product's optical performance.

An optoelectronic chip and a communication device, relating to the technical field of optoelectronic chips. The optoelectronic chip comprises a substrate, a laser device and an optical device, the substrate being provided with an optical conduction part and an accommodation cavity which are adjacent to each other. The optical conduction part is internally provided with a first waveguide, the first waveguide comprising at least two sub-waveguides which are arranged at intervals in a first direction, the projections of any two adjacent sub-waveguides among the at least two sub-waveguides in the first direction overlapping, and the interval of any two adjacent sub-waveguides being within a preset range. The laser device is arranged in the accommodation cavity, and the laser device is in coupling connection to one of the first waveguides. The laser device, the optical conduction part and the optical device are sequentially arranged, and the optical device is in coupling connection to the other one of the first waveguides. By providing the first waveguide, the present application uses the coupling design of the plurality of sub-waveguides to change the height position of a laser on different waveguides, thereby achieving alignment of laser devices of different laser emission heights and waveguides, and improving the degree of coupling and lowering coupling loss.

The invention discloses an optical interface structure of an integrated photonic chip for a fiber-optic gyroscope and an optical coupling method, and belongs to the technical field of integrated optics and optical fiber sensing. All input and output ports of the integrated photon chip are arranged on a coupling end face on the same side of the chip, the ports comprise at least two signal ports and two auxiliary ports, the signal ports are used for connecting tail fibers of polarization maintaining fiber rings of all measuring axes of the fiber-optic gyroscope, and the auxiliary ports are connected with a through type auxiliary coupling optical channel in the chip; each port is integrated with a spot size adaptation unit, and the spot size adaptation unit is used for matching the spot size of the polarization maintaining optical fiber and the chip waveguide; the integrated photon chip realizes single-side end face alignment coupling with the multi-channel polarization-maintaining optical fiber array through the coupling end face, tail fibers of polarization-maintaining optical fiber rings of all measuring axes of the optical fiber gyroscope are directly solidified in the multi-channel polarization-maintaining optical fiber array, a head channel and a tail channel of the multi-channel polarization-maintaining optical fiber array are aligned with two auxiliary ports of the chip respectively, and no extra welding link is needed. According to the invention, the problems of dispersed channel-by-channel coupling of optical interfaces, complex alignment of two-side FAs, large dual-link coupling loss, serious polarization cross coupling and uncontrollable coupling quality are solved, the overall precision and environmental stability of the fiber-optic gyroscope are remarkably improved, the method is suitable for various fiber-optic gyroscopes with single axes, multiple axes and the like, and the system integration level and the assembly consistency are remarkably improved.

The invention discloses a photoelectric chip with power attenuation regulation and control and real-time monitoring functions. The photoelectric chip comprises a coupling waveguide, a connecting waveguide, a light beam splitting structure and a variable optical attenuator, an optical signal enters the chip through the input coupling waveguide and is transmitted to the optical beam splitting structure through the first connecting waveguide, the optical beam splitting structure divides the optical signal into a monitoring signal and a main transmission signal, and the monitoring signal is transmitted to the first variable optical attenuator through the optical beam splitting structure and the second connecting waveguide in sequence and then is connected to the photoelectric detection system through the monitoring output coupling waveguide. The main transmission signal is transmitted to the second variable optical attenuator through the optical beam splitting structure and the third connection waveguide in sequence, and then is transmitted back to the original optical fiber link through the main signal back-transmission coupling waveguide. The chip disclosed by the invention can be prepared on a large scale by adopting a standard micro-nano process, is low in coupling loss and high in compatibility, can be customized on a single chip or in an array manner, is accurate in monitoring and convenient to install, and can be widely applied to real-time monitoring and attenuation regulation and control of links in the fields of optical fiber communication, optical sensing and the like.

The invention provides a silicon-erbium-doped lithium niobate photon calculation chip, which adopts a wafer-to-wafer bonding mode, realizes heterogeneous integration of silicon and erbium-doped lithium niobate, and integrates devices such as a gain type delay array, a gain type electro-optical modulator, an interlayer coupler, a waveguide cross junction, a silicon-based phase shift array and an end face coupler in a monolithic manner. Complicated inter-chip coupling technology and optical interconnection steps are not needed, and inter-chip coupling loss is effectively avoided. The advantages of optical amplification on an erbium-doped lithium niobate sheet are fully exerted, so that the gain type electro-optical modulator and loss type devices such as a waveguide gain type delay line have gain performance, optical loss on the sheet is further compensated, and meanwhile, the signal processing speed and the capacity of executing complex calculation tasks are remarkably improved. Meanwhile, the advantages of high integration level and mature process of silicon are exerted; the advantage of high-speed electro-optical modulation of lithium niobate is exerted, the limitation of a single material platform on the integration scale is broken through, and high-density integration of devices is achieved.

The invention provides an on-chip optical sensor for medical detection and a manufacturing method thereof, and relates to the technical field of on-chip optical sensors. According to the scheme, the device mainly comprises a substrate, a double-peak waveguide interference structure, a near-infrared photoelectric detector and a micro-fluidic channel, the double-peak waveguide interference structure is arranged on the upper surface of the substrate, comprises a waveguide layer and is used for amplifying refractive index change and outputting an interference signal; the micro-fluidic channel and the near-infrared photoelectric detector are respectively arranged in a sensing area and an output area on the upper surface of the waveguide layer; recognition molecules are arranged in the micro-fluidic channel and are used for being specifically combined with target molecules of a medical sample and generating refractive index change; and the near-infrared photoelectric detector is used for reading the interference signal and converting the interference signal into an electric signal. According to the scheme, the machinable absorption layer is directly integrated in the evanescent field area of the double-peak waveguide, on-chip direct reading of waveguide interference signals is achieved, coupling loss is reduced, and the signal-to-noise ratio is remarkably increased.

The utility model discloses an O wave band end face coupler based on a silicon nitride multi-cone waveguide. The O wave band end face coupler is characterized in that a waveguide layer is composed of three double-cone input waveguides, two double-cone waveguides, a single-cone waveguide and a straight waveguide connected with the single-cone waveguide; according to the utility model, through the introduction of the multi-conical structure of the biconical input waveguide, the biconical waveguide and the single-conical waveguide, the mode mismatch between the waveguides and the optical fiber is effectively reduced, so that the loss caused by mode adaptation is reduced, the efficient optical coupling between the optical fiber and a chip is realized, and the structure between the waveguides is compact; only single exposure and etching are needed, the process complexity is reduced, the coupling loss in the O wave band is low, and the bandwidth is large.

The invention relates to a multi-modal fusion projection-based bearing fault diagnosis method under strong noise and variable working conditions, and belongs to the technical field of bearing fault diagnosis, and the method comprises the following steps: S1, collecting vibration and current signals, and carrying out the frequency domain transformation; s2, fusing vibration and current features by using a dual-path current guide vibration feature fusion strategy; s3, introducing a learnable class adaptive projection matrix, and mapping the fused features to a subspace with an invariable operation state; and S4, constructing an encoder-projection coupling loss function, and realizing joint optimization of the dual-path encoder and the class adaptive learnable projection matrix, so that the model can learn representation with a constant operation state and class discrimination degree at different rotating speeds, and diagnosis and classification are performed on bearing faults.

The present disclosure provides a planar lightwave circuit that enables a reduction in coupling loss upon connection to an optical element. Specifically, provided is a planar lightwave circuit characterized in that: the thickness of part of a core layer varies symmetrically with respect to the center of a core cross-section obtained by horizontally cutting the core layer in the thickness direction thereof; and the center position of each input port of two or more optical waveguides is located at the same height from the bottom surface of a lower cladding layer, or the center position of each output port of two or more optical waveguides is located at the same height from the bottom surface of the lower cladding layer.

A thin film lithium niobate waveguide scattering and absorption loss spectrum separation detection method comprises the following steps: acquiring transmission loss of a thin film lithium niobate waveguide under different wavelengths and an energy distribution ratio of each wavelength guided mode in different media so as to determine a total transmission loss and a mode field space energy ratio; and constructing a space energy attribution model based on the total transmission loss and the mode field space energy ratio. In the space energy attribution model, an interface coupling loss item is introduced, and a loss dominant interval is established according to the interface coupling loss item. And extracting a loss spectrum in the loss dominant interval, and carrying out consistency verification on the loss spectrum by taking a mode field space energy proportion as a weight so as to output a scattering loss spectrum and an absorption loss spectrum. Under the condition of a high leakage field, even if surface absorption and scattering coupling loss caused by cladding surface pollution, moisture adsorption and interface defects does not meet the linear superposition relation any more, the accuracy of waveguide detection can be guaranteed.

The invention relates to a preparation method of a high-speed EML laser chip, which belongs to the technical field of semiconductor manufacturing, and comprises the following steps: S1, depositing a silicon dioxide film on an epitaxial wafer; s2, uniformly coating photoresist on the epitaxial wafer, performing photoetching by using an exposure machine, simultaneously defining a pattern of a shallow etching waveguide and a pattern of a deep etching waveguide in the photoetching step, performing exposure, and forming a corresponding photoresist mask on the upper surface of the epitaxial wafer; s3, etching the initial mask layer to form a silicon oxide mask pattern with the same shape as the photoresist mask; s4, etching the DFB part and the EAM part for the first time to obtain a self-aligned DFB ridge waveguide structure and an EAM shallow ridge waveguide structure; s5, uniformly coating the photoresist again, exposing and removing the photoresist above the DFB part; s6, depositing silicon dioxide on the epitaxial wafer; step S7, stripping silicon dioxide above the photoresist; and S8, etching the EAM part for the second time to obtain a DFB ridge waveguide structure and an EAM ridge waveguide structure which are strictly aligned, so that the coupling loss can be effectively reduced.

The invention discloses a time-frequency consistency electroencephalogram signal generation method and system based on distance constraint. A composite loss function containing three losses of time-distance coupling, frequency-distance coupling and phase synchronization is designed. Time-distance coupling loss is weighted according to the distance between the electroencephalogram virtual channel and the source channel, and the consistency of signals of the electroencephalogram virtual channel far away from the source channel and real signals in the time domain is enhanced; frequency-distance coupling loss, amplitude consistency between an electroencephalogram virtual channel signal with a short strengthening distance in a low frequency band and a real signal, and frequency consistency between an electroencephalogram virtual channel signal with a long strengthening distance in a high frequency band and the real signal; according to the phase loss item, the phase synchronism is strengthened in a specific frequency range for the task state electroencephalogram signals, and the method is suitable for a task state scene. According to the method, the time-frequency domain consistency, the channel distance and the task state phase coherence of the generated signals are fully considered, and the signal generation quality of the electroencephalogram virtual channel (especially the far end) is effectively improved.

The invention discloses an optical fiber coupling efficiency improving method based on a bat algorithm. The method comprises the following steps that optical power data are collected and preprocessed; constructing a coupling parameter search space model; initializing an improved submerged space enhancement-bat algorithm, and outputting an initial coupling parameter vector; introducing countercurrent coding to generate a submerged space vector; calculating and outputting an optimal action vector through a differentiable strategy flow mapping mechanism; obtaining a current iteration optimal bat individual; outputting a coupling parameter vector of the global optimal bat individual; and the improved submerged space enhancement-bat algorithm is recalled to perform parameter optimization calculation, so that the optimization speed and the global optimal stability of optical fiber coupling are effectively improved, the coupling loss is remarkably reduced, and the automatic adjustment precision and the optical power stability of the system are improved.