109 results about "Transverse mode" patented technology

An acoustic wave device, a radio frequency filter and an electronics module are provided. The acoustic wave device, comprises a layer of piezoelectric material, a pair of interdigital transducer electrodes disposed on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar through a central region of the interdigital transducer electrode towards an edge region of the interdigital transducer electrode, each of the plurality of electrode fingers having a width in a direction perpendicular to the extension of the electrode fingers that is smaller in the edge regions than in the central regions, and trench portions located in the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The acoustic wave device provides effective suppression of transverse modes.

The invention provides a well drilling anti-interference communication system based on a VCSEL (Vertical Cavity Surface Emitting Laser), the VCSEL and a manufacturing method thereof, and the manufacturing method comprises the following steps: calculating the light field intensity distribution of a high-order transverse mode through an intrinsic mode expansion method and a Laguerre-Gaussian model based on the epitaxial structure parameters of a laser; determining a target area which begins to perform downward annular etching on the surface of the p-DBR layer, wherein the target area coincides with a light field intensity peak area of the high-order transverse mode; performing annular etching in the target area to form an annular groove, and etching at least seven pairs of p-DBR layers inwards in the groove; the communication system comprises a signal transmitting end arranged on the derrick side, and the signal transmitting end is provided with the vertical cavity surface emitting laser; the p-DBR region of the vertical cavity surface emitting laser is provided with an annular etching structure; the graded-index fluorinated plastic optical fiber is used as a transmission medium and is connected with the derrick side and the logging room side; and the optical signal receiving end is arranged at the logging room side and is used for receiving and converting the optical signal into an electric signal.

The invention relates to the technical field of lasers, in particular to a vertical-cavity surface-emitting laser and a preparation method thereof, and the vertical-cavity surface-emitting laser comprises a substrate layer, an N-type DBR structure, a first spacing layer, an active layer, a second spacing layer and a P-type DBR structure which are stacked in sequence; wherein the P-type DBR structure is formed by alternately arranging a high-refractive-index P-type semiconductor layer and a low-refractive-index P-type semiconductor layer for a plurality of cycles, and the low-refractive-index P-type semiconductor layer is a P-type semiconductor layer containing an Al component; a low-refractive-index P-type semiconductor layer adjacent to the second spacing layer in the P-type DBR structure is used as a first oxidation limiting layer, and the molar fraction of Al component in the first oxidation limiting layer before oxidation is greater than 0.98. According to the invention, the single transverse mode output characteristic of the vertical cavity surface emitting laser under high power can be improved at least.

The invention relates to the field of electronic component preparation processes, in particular to a high-performance temperature compensation surface acoustic wave filter and a manufacturing method thereof. An interdigital transducer, wherein the interdigital transducer is located at one side of the piezoelectric substrate; the transition layer is located on the side, away from the piezoelectric substrate, of the interdigital transducer, and the transition layer covers the interdigital transducer and prevents metal elements of the interdigital transducer from diffusing outwards; the functional layer is located on the side, away from the interdigital transducer, of the transition layer, the functional layer covers an active area of a metal finger strip of the interdigital transducer to form a high-sound-velocity area, the end, away from the active area, of the metal finger strip of the interdigital transducer forms a low-sound-velocity area, and a sound velocity difference is formed between the high-sound-velocity area and the low-sound-velocity area; therefore, transverse mode clutters are suppressed; the temperature compensation layer is located on the side, away from the transition layer, of the functional layer, and the temperature compensation layer covers the functional layer and the piezoelectric substrate; lateral mode clutters in TC-SAW are suppressed, and metal diffusion is suppressed at the same time.

The invention discloses a surface acoustic wave filter and a multiplexer surface acoustic wave filter, and the surface acoustic wave filter comprises a first piezoelectric substrate and a first interdigital transducer which is arranged on the first piezoelectric substrate. The first interdigital transducer comprises a first bus bar, a second bus bar, a plurality of first electrode fingers and a plurality of second electrode fingers, the first bus bar and the second bus bar are oppositely arranged, the first electrode fingers are led out from the first bus bar and extend towards the second bus bar, the second electrode fingers are led out from the second bus bar and extend towards the first bus bar, and the first electrode fingers and the second electrode fingers are arranged at intervals; the plurality of first electrode fingers and the plurality of second electrode fingers are mutually overlapped to form a first overlapping area, and the boundary shape of the first overlapping area conforms to a trigonometric function curve in the sound wave propagation direction; and the shapes of the first bus bar and the second bus bar are matched with the boundary shape of the first overlapping region. The technical effects that the transverse mode can be inhibited, and the small-size surface acoustic wave filter can be realized are achieved.

Single-transverse-mode laser diodes that include a bowtie-shaped ridge waveguide. Related apparatuses, data storage devices, computing systems, and methods.

This application provides a semiconductor laser and a terahertz source for generating terahertz waves. The semiconductor laser includes: a substrate; a mesa located on the substrate; and a ridge waveguide and lateral coupling gratings located on the mesa, with the lateral coupling gratings located on both sides of the ridge waveguide. The lateral coupling gratings are configured such that the frequency difference between the fundamental transverse mode wavelength and the second-order transverse mode wavelength of the lasing light emitted by the semiconductor laser is 0.1 THz–10 THz. The semiconductor laser of this application, through the optimized configuration of the ridge waveguide and the lateral coupling gratings on both sides, precisely achieves simultaneous output of the fundamental and second-order transverse modes with a frequency difference on the order of terahertz. Combined with a polarization controller and a nonlinear crystal, it can stably output terahertz waves in the target frequency band. Compared with traditional solutions, the semiconductor laser of this application can simultaneously output the fundamental and second-order transverse modes with a frequency difference on the order of terahertz, offering advantages in miniaturization and low cost.

To achieve high-power single transverse mode laser, we here propose a supersymmetry (SUSY)-based triple-ridge waveguide semiconductor laser structure, which is composed of an electrically pumped main broad-ridge waveguide located in the middle and a pair of lossy auxiliary partner waveguides. The auxiliary partner waveguides are designed to provide dissipative modes that can phase match and couple with the higher-order modes in the main waveguide. By appropriately manipulating the gain-loss discrimination of the modes in the laser cavity, one can effectively suppress all the undesired higher-order transverse modes while keeping the fundamental one almost unaffected, thereby ensuring stable single-mode operation with a larger emitting aperture and accordingly a higher output power than a conventional single-transverse-mode ridge waveguide diode laser.

According to the laser generating device and the laser system, the image transmission device is introduced, the object image surface of the image transmission device is accurately overlapped with the two cavity reflectors of the resonant cavity, the important beneficial effects are achieved, the effective transmission distance of light waves between the two cavity reflectors is equivalently eliminated optically, and the laser generating device and the laser system have the advantages of being simple in structure and convenient to use. Therefore, the inherent diffraction effect and the mode selection capability of the resonant cavity are thoroughly inhibited; the direct result is that a large number of laser transverse modes with different orders are allowed to simultaneously meet oscillation conditions and start oscillation in a cavity, and light fields of the multiple transverse modes are combined into a large-mode-field output light beam with the spot size equivalent to the aperture of a gain medium after incoherent superposition. Moreover, the near-field energy distribution is converted from the conventional Gaussian distribution to super Gaussian distribution with a flat top and a steep edge.

An acoustic wave device, a radio frequency filter, and an electronics module are provided. The acoustic wave device includes a layer of carrier substrate, a layer of dielectric material, a layer of piezoelectric material, a pair of interdigital transducer electrodes, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar to the distal ends of the electrode fingers at an edge region of the interdigital transducer electrode, and trench portions located in the upper surface of the layer of piezoelectric material, said trench portions being overlapped by the edge regions of the interdigital transducer electrodes, the electrode fingers having a width at their distal end that is greater than the width of the rest of the electrode finger. The acoustic wave device provides effective suppression of transverse modes.

In one embodiment, the present disclosure is directed to a system for providing improved electric field uniformity to a plasma chamber receiving multiple signal inputs. The system includes one or more dielectrics distributing received energy to one or more antennas. The one or more dielectrics have N receiving areas. N circular waveguides are positioned over the N receiving areas. Each of waveguides has a mode converter converting a received first transverse mode signal to a second transverse mode signal to be output by the circular waveguide to the corresponding receiving area. At least one phase adjuster circuit adjusts the phase of at least one of the first transverse mode signals such that adjacent circular waveguides have their received first transverse mode signals differ in phase by approximately 360 / N.

A bulk acoustic wave resonance device includes: an acoustic reflection layer; the first electrode layer comprises a first resonance part and a first extension part; a piezoelectric layer; the second electrode layer comprises a second resonance part and a second extension part; a dielectric layer, wherein a first dielectric part of the dielectric layer is located between a part of the first extension part and the piezoelectric layer; the load layer corresponds to the second extension part; the first attenuation area is used for attenuating sound waves; and the first limiting area is used for reflecting sound waves. The first-order transverse mode can pass through the first attenuation area without being affected, and then is fully reflected back to the resonance area in the first limiting area, so that transverse leaky waves are reduced; the high-order lateral parasitic mode entering the first attenuation region is attenuated, and only a small number or even no high-order lateral parasitic mode enters the first confinement region, so that the parallel impedance value and the corresponding Q value can be improved.

The invention discloses a compact arbitrary transverse mode laser. The laser comprises a pumping source, a pumping focusing optical system, a laser total reflective mirror, a laser gain medium, a laser output mirror and an astigmatism mode converter, the pumping source emits pumping light in a gain medium absorption band; the pump light is focused and then enters the gain medium; the gain medium absorbs the pump light and generates laser gain; the total reflective mirror highly reflecting laser wavelength and the output mirror partially transmitting the laser wavelength jointly form a simple linear resonant cavity. When the laser gain medium is inclined by a preset angle relative to the optical axis of the resonant cavity, meridian light and sagittal light pass through different optical paths of the gain medium to introduce astigmatism, an HG mode facing the directions of two astigmatism symmetry axes can be reproduced, and modes facing other directions cannot be reproduced due to the astigmatism effect. Therefore, when the pump light deviates from the axis of the resonant cavity in the directions of the two astigmatic symmetry axes, any high-order HG mode with mode ordinal numbers not being zero in the two directions can be excited, and any LG mode laser can be generated through astigmatic mode conversion.

The invention provides a surface acoustic wave structure, a surface acoustic wave filter and communication equipment, and is characterized in that the lengths of at least part of first interdigital electrodes are set to be sequentially increased in the surface acoustic wave propagation direction, the increasing amplitudes are sequentially reduced, and the lengths of second interdigital electrodes are set to be sequentially reduced in the surface acoustic wave propagation direction; and the reduction amplitude is sequentially reduced, so that the excitation intensity of the surface acoustic waves of the interdigital transducer in each region in the surface acoustic wave propagation direction is non-linearly changed, and the excitation intensity is weakened in the region where a part of first interdigital electrodes arranged at the rear part in the surface acoustic wave propagation direction are located. The weakening can improve the near-band suppression capability of the surface acoustic wave filter, so that the resonant frequency burr phenomenon caused by transverse sound waves can be reduced or suppressed, namely, the resonant frequency splitting phenomenon is not easily caused. In addition, the surface acoustic wave structure provided by the invention does not need to be additionally provided with a structure for inhibiting a transverse mode, and is simple in preparation process, low in preparation cost and small in occupied area.

A method of manufacturing an acoustic wave device is provided. The method of manufacturing the acoustic wave device comprises providing a layer of piezoelectric material, disposing a pair of interdigital transducer electrodes on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar towards an edge region of the interdigital transducer electrode at the distal ends of the electrode fingers, and etching trench portions into the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The formation of the trench portions through etching results in an easier fabrication, that is less likely to damage the interdigital transducer electrodes.

A rare-earth doped optical fiber (active optical fiber) is presented that exhibits a thermal coefficient of optical refraction (dn / dT) of the core region that is reduced relative to the thermal coefficient of optical refraction (dn / dT) of the surrounding cladding. The reduction of the dn / dT of the core region has been found to reduce the impact of transverse mode instability (TMI) in the presence of high levels of pump power (or other conditions that can also increase the thermal load present in the core region). Specifically, it has been found that reducing the dn / dT of the core region relative to the dn / dT of the cladding by at least 10% is sufficient to extend the temperature range in which the active optical fiber is maintained in single mode operation. The reduction of the dn / dT can be provided by modifying the dopants introduced into the core region, where, for example, it is known to introduce boron into ytterbium doped optical fibers to reduce the dn / dT of the core region.

A surface acoustic wave device can have a piezoelectric layer and at least one interdigital transducer electrode thereon with a trapezoidal shape. This can be useful to fill dead space or voids between nonparallel elements on the layer. For example, an array with ranks of slanted interdigital transducer electrodes may not be aligned with non-slanted elements (e.g., a surface acoustic wave filter). This can leave voids or openings with unused portions of the piezoelectric layer. Trapezoidal elements such as those described here can solve this problem and help suppress transverse modes.

The utility model discloses an elastic wave resonator, a filter and electronic equipment, and belongs to the technical field of surface acoustic waves. The elastic wave resonator comprises a supporting layer, a piezoelectric layer and an interdigital transducer which are sequentially stacked, the interdigital transducer comprises a plurality of first electrode fingers, second electrode fingers and bus bars oppositely arranged in the first direction, and the first electrode fingers and the second electrode fingers extend in the first direction and are alternately arranged in the second direction; the intersection part of the first electrode fingers and the second electrode fingers forms an aperture area, and a gap area is formed between the aperture area and the bus bar; the first width of the first part of the first electrode finger in the gap area is larger than the second width of the second part in the aperture area, and the third width of the third part of the second electrode finger in the gap area is larger than the fourth width of the fourth part in the aperture area. The at least one first part and the at least one third part are provided with a load layer at one side close to the piezoelectric layer and / or one side far away from the piezoelectric layer, so that the generation of a transverse mode can be inhibited.

The invention provides an optical chip for atom regulation and control and a regulation and control method, and belongs to the technical field of optical signal processing. The optical chip comprises a chip substrate, an optical waveguide integrated on the chip substrate, an acousto-optic modulator, an external port and a port facing an atomic array. The acousto-optic modulator generates sound waves through an interdigital transducer, and the sound waves interact with the optical signals in the acousto-optic interaction waveguide, so that at least one of the amplitude, the phase, the polarization, the frequency, the transverse mode and the transmission direction of the optical signals is accurately adjusted. The optical chip can also be integrated with a nonlinear optical frequency conversion module for changing the frequency of the optical signal; and the optical signal multiplexing module is used for performing beam splitting, filtering, frequency division or mode division multiplexing and the like on the optical signal. The external port is used for inputting / outputting optical signals, and the port facing the atom array outputs the optical signals to the atom array in a free space light beam mode and can collect the optical signals emitted by atoms.

The application relates to the technical field of lasers, in particular to a semiconductor laser and a design method thereof. The semiconductor laser comprises a substrate, a first electrode and a stack structure located on the substrate, the first electrode surrounds the stack structure, the stack structure comprises a first DBR layer, a second DBR layer, an active region and a third DBR layer, the third DBR layer comprises a first part, a second part and a third part which are sequentially stacked, the second part comprises an oxidation layer and a non-oxidation layer, the oxidation layer surrounds the non-oxidation layer, the non-oxidation layer serves as an oxidation hole, the third DBR layer has an annular groove, the outer diameter of the annular groove is smaller than the diameter of the oxidation hole; a second electrode; wherein the width of the annular groove w and the radius of the central light-out hole a satisfy r1-a < w < r2-a wherein, r1 is the abscissa corresponding to 1 / e2 of the base transverse mode electric field intensity peak, r2 is the abscissa corresponding to 1 / e2 of the first-order transverse mode electric field intensity peak. The application is at least beneficial to improving the performance of the semiconductor laser and reducing the parameter determination complexity of the semiconductor laser.

The application relates to an AlGaInP-based transverse mode semiconductor laser and a preparation method thereof. The laser comprises, from bottom to top, a GaAs substrate, a GaAs buffer layer, a Ga 0.5 In 0.5 P lower transition layer, an Al 0.5 In 0.5 P lower confinement layer, an (Al 1‑x1 Ga x1 ) y1 In 1‑y1 P graded lower waveguide layer, a Ga 1‑x2 In x2 P first quantum well, an (Al 1‑x3 Ga x3 ) y2 In 1‑y2 P barrier layer, a Ga 1‑x4 In x4 P second quantum well, an (Al 1‑ x5 Ga x5 ) y3 In 1‑y3 P graded upper waveguide layer, an Al 0.5 In 0.5 P first upper confinement layer, an Al 0.5 In 0.5 P second upper confinement layer, a Ga 0.5 In 0.5 P upper transition layer and a GaAs cap layer. The AlGaInP-based transverse mode semiconductor laser provided by the application increases the thickness of the Al 0.5 In 0.5 P first upper confinement layer, reduces the doping concentration of the Al 0.5 In 0.5 P first upper confinement layer, realizes the reduction of the difference of transverse refractive indexes, stabilizes the basic transverse mode and improves the kink power, and avoids the influence of current diffusion on electrical parameters after the thickness of the Al 0.5 In 0.5 P first upper confinement layer is increased.

The invention discloses a microchip single-frequency pulse vortex light laser generating device which comprises a pump light source, an output collimating mirror, a focusing lens, an axicon and a microchip resonant cavity which are sequentially and coaxially arranged. A space light beam or an optical fiber coupling light beam emitted by the pump light source is expanded and collimated by the output collimating lens, then converted by the focusing lens and the axicon and shaped into an annular light beam without orbital angular momentum, the annular light beam is irradiated to the microchip resonant cavity, the microchip resonant cavity is moved in the direction of a light path, and the orbital angular momentum is formed. The positions of the microchip resonant cavity and the focus of the focusing lens are adjusted, transverse mode matching in the resonant cavity is achieved, single-mode intracavity oscillation is generated, and a single-frequency pulse vortex beam is output by controlling the inclination angles of the front surface and the rear surface of the microchip resonant cavity.

The application relates to a method and device for measuring the relative refractive index difference between a fiber core and a cladding. The method comprises: inputting single transverse mode laser beams of different wavelengths in a target application wave band into a fiber to be measured at equal wavelength intervals, obtaining a light spot pattern of the fiber to be measured at each wavelength, and then obtaining a two-dimensional measurement matrix with the row and column sizes being the number of pixel points of the light spot pattern and the number of sampling wavelengths; performing Fourier transform on each row of data of the two-dimensional measurement matrix and adding the results to obtain a differential mode group delay test value of a first high-order mode relative to a base mode; and searching a lookup table of the change of a differential mode group delay theoretical value corresponding to a high-order mode of the fiber to be measured with the core-cladding refractive index difference to find a differential mode group delay theoretical value closest to the differential group delay test value under the core diameter of the fiber to be measured, and obtaining the core-cladding refractive index difference of the fiber to be measured. The method can realize efficient, accurate and non-invasive measurement of the core-cladding refractive index difference of a long link fiber.

The invention discloses a transmitting interdigital transducer structure for improving out-of-band rejection of a surface acoustic wave filter. An IDT pattern is formed between two bus bars through a plurality of electrodes; the IDT pattern is formed by crosswise arranging a positive electrode pair and a negative electrode pair, and each electrode pair is composed of at least two electrodes with the same polarity; each electrode comprises a true finger and a false finger which are oppositely arranged, and all the true fingers and all the false fingers in any electrode pair are connected through inner connecting strips. The upper part area of each real finger transversely extends towards the two sides of the width to form two end heads, so that the width of the end heads is larger than that of the real finger; wherein one end is attached to the bus bar, and the other end is attached to the true finger inline bar. According to the surface acoustic wave filter, the end heads are arranged and the sizes of the end heads are reasonably controlled, so that the reflection conditions of sound waves at the boundaries of the bus bars and the inner connecting bars are changed, the structure can restrain a transverse mode generated in the sound wave propagation process, and the out-of-band rejection of the surface acoustic wave filter is improved.

The application is based on a laser digital frequency locking master module and a digital frequency locking system of a PDH technology, which comprises a DDS, a frequency mixer, a low-pass filter, a PID filter unit, an image processing unit, a frequency locking state discriminator and a triangular wave generator realized by an FPGA of the master module; the DDS outputs two signals, one of which is directly output, and the other of which is mixed with a first PD signal, and after the error signal is obtained through the low-pass filter, it enters the PID loop filter unit; the input error signal is filtered through multiple filters and outputs three control signals, which correspond to different actuators respectively; the master controls the spot mode according to the gray distribution of the spot image and the circumscribed rectangle of the spot, calculates the different transverse mode ratios, estimates the transmitted light power, the cavity rear spot image signal and a second PD signal jointly enter the frequency locking state discriminator to judge the frequency locking state and the frequency locking quality, and the triangular wave generator controls the laser frequency sweep according to the triangular wave signal, which improves the integration and the frequency locking success rate of the system and reduces the operation complexity.

The invention belongs to the field of piezoelectric acoustic wave devices, and particularly relates to an acoustic surface wave resonator of an LN-POI multilayer structure. The resonator comprises an interdigital electrode layer, a piezoelectric layer, an oxide buried layer, a polycrystalline silicon layer and a substrate which are stacked from top to bottom, the interdigital electrode layer is composed of a first bus bar, a second bus bar and electrode finger bars connected to the inner sides of the two bus bars. The electrode finger strips connected with the same bus bar are parallel, and all the electrode finger strips and the bus bar form an inclination angle of 20-25 degrees; the large electromechanical coupling coefficient and the working frequency of the resonator are improved, the transverse mode can be suppressed, and the performance of the resonator is improved.

A transducer structure with means for transverse mode suppression comprises a piezoelectric substrate, and a pair of inter-digitated comb electrodes on the piezoelectric substrate. The first comb electrode has a first bus bar and a plurality of electrode fingers alternating with shorter dummy fingers, both extending from the first bus bar. The second comb electrode has a second bus bar and a plurality of electrode fingers extending from the second bus bar. The dummy fingers of the first bus bar face the fingers of the second bus bar and are separated from the fingers by first gaps. A transverse mode suppression layer is disposed partially underneath the first gap. The phase velocity of a guided wave is smaller in the region of the transverse mode suppression layer compared to the phase velocity of the guided wave in the central region underneath the alternating fingers of the first and second electrodes.

This invention relates to the field of optical resonator locking technology, and discloses a modulation-free optical resonator locking method and apparatus based on optical field spatial mode mismatch, aiming to solve the problems of complexity and noise introduction in traditional PDH locking technology systems. This method uses the superposition field of the spatial fundamental mode and the second-order transverse mode excited by mode mismatch as the input light field of the optical cavity. After breaking the mode orthogonality through pinhole clipping, the reflected light is split and a controllable Gouy phase shift is introduced. Two photodetectors detect the signals and differentially process them to generate an error signal, thus achieving optical resonator locking. This invention requires no external modulation and demodulation components, has a simple structure, high stability, and locking effect comparable to traditional PDH methods. It has low requirements for spot centering and partition consistency, providing a simple and effective way to achieve cavity frequency stabilization in precision optical systems, and is suitable for fields such as laser frequency stabilization and precision measurement.

The embodiment of the invention provides a surface acoustic wave resonator, a filter and a multiplexer. The surface acoustic wave resonator comprises a substrate; the piezoelectric layer is positioned on one side of the substrate; an electrode layer; the piezoelectric layer is located on one side away from the substrate; the electrode layer comprises a plurality of interdigital electrodes; the plurality of interdigital electrodes comprise a plurality of first interdigital electrodes and a plurality of second interdigital electrodes; the first interdigital electrodes and the second interdigital electrodes are sequentially and alternately arranged in the first direction and extend in the second direction. A lateral mode suppression layer; the transverse mode suppression layer at least comprises a first transverse mode suppression layer located between the piezoelectric layer and the electrode layer; in the first direction, the size between any two adjacent first interdigital electrodes and the size between any two adjacent second interdigital electrodes are the same and are lambda; the thickness of the transverse mode suppression layer is h; wherein h is larger than or equal to 0.0025 lambda and smaller than or equal to 0.03 lambda, the transverse mode can be suppressed by arranging the transverse mode suppression layer, and then the performance of the surface acoustic wave resonator is improved.

The invention discloses a system for generating a multi-spectral-line CO2 laser pulse seed, which belongs to the technical field of CO2 lasers and comprises a resonant cavity comprising a reflecting element group, a first grating and a gain medium; the first grating is used for spatially separating light beams with different wavelengths in the gain medium to realize simultaneous oscillation of multiple spectral lines; the reflecting element group is used for reflecting each spectral line beam split by the first grating back to the gain medium in parallel; the beam selecting and expanding mechanism comprises an aperture-adjustable diaphragm group and a beam expanding lens group and is used for controlling the transverse mode and spatial distribution of each spectral line; and the cavity emptying structure is used for outputting all the light beams in the resonant cavity when the photons are accumulated to the maximum value so as to form a multi-spectral-line CO2 laser pulse seed. The pulse seed generation device can be applied to the LPP extreme ultraviolet lithography technology to generate pulse seeds for driving laser, and has the advantages of being low in cost, stable in output and good in pulse quality.