268 results about "Liquid crystal spatial light modulator" patented technology

In an autostereoscopic display apparatus comprising a liquid crystal spatial light modulator having an array of pixels of different colors, each pixel comprising plural domains of different polar alignments, and a parallax element comprising an array of optical elements having geometric axes extending in parallel across the spatial light modulator in an inclined direction, the domains are shaped to improve the angular contrast uniformity. For each individual domain, a notional line parallel to the geometric axes of the optical elements of the parallax element has a total length of intersection with the individual domain, summed over adjacent pixels of the same color, is the same for all positions of the notional line. The total length of intersection for different domains is proportional to the area of the individual domains.

The invention provides an interferometry system, which comprises a unit, a phase modulation type spatial light modulator, an interferometer and a light detector; the unit is used for generating mutually orthogonal linearly polarized lights in the polarized state, and the mutually orthogonal linearly polarized lights are respectively called reference light and testing light; the phase modulation type spatial light modulator is arranged in the light path of the reference light or the testing light, and is used for changing spatial phase distribution before light waves; the spatial light modulator is provided with a plurality of pixels, each of which has specific phase distribution; the light, the phase of which is modulated by the spatial light modulator, is called modulated light, and the light which is not modulated is called unmodulated light; the interferometer is based on the modulated light and the unmodulated light to carry out interferometry; the coherent light generated by the interferometer is detected by the light detector; and moreover, the pixels of the spatial light modulator are corresponding to the pixels of the light detector. The system provided by the invention not only can carry out measurement during the phase shift distribution of a plurality of spatial carriers, but also can carry out high-precision dynamic measurement. The invention also provides a spatial phase-shifting unit and a liquid crystal spatial light modulator phase-correcting unit.

A system and method for simulating atmospheric turbulence for testing optical components. A time varying phase screen representing atmospheric turbulence is generated using Karhunen-Loeve polynomials and a splining technique for generating temporal functions of the noise factor for each Zernike mode. The phase screen is input to a liquid crystal spatial light modulator. A computer display allows the user to set geometric characteristics, and select between methods for generating atmospheric turbulence including Karhunen-Loeve polynomials, Zernike polynomials, and Frozen Seeing.

Simultaneous amplitude and phase control of ultrafast laser pulses using a single, linear (one-dimensional) liquid crystal spatial light modulator is described. Amplitude shaping is accomplished by writing a high-frequency phase grating having a spatial period much smaller than the spectral focus (over-sampling), onto the modulator, and diffracting away selected frequencies in a controllable manner, while spectral phase control is imparted by adding an appropriate slow phase bias to the modulator. The close pixel spacing, large number of pixels, and small footprint of the reflective spatial light modulator employed with an angular wavelength dispersive element in a folded Martinez stretcher, enables a simple and compact apparatus to be achieved. The high reflectivity of the spatial light modulator results in a highly efficient pulse shaper when either a prism or diffractive grating is used for the angular dispersive element. The use of a transmissive spatial light modulator in an unfolded Martinez stretcher configuration is also described.

The invention discloses an optical system generating screw type Bessel beams and a generating method. The optical system is composed of a He-Ne laser device, a polarizer, a first beam expander, a binary amplitude grating, a second beam expander, an aperture diaphragm, a liquid crystal spatial light modulator, an axicon and a CCD camera. Gauss beams emitted from the He-Ne laser device are converted into 0-degree linearly polarized light after passing through the polarizer with a 0-degree polarizing direction, beam expanding is carried out on the 0-degree linearly polarized light through the first beam expander, the 0-degree linearly polarized light is vertically emitted into the binary amplitude grating, generated diffracted light passes through the second beam expander, the diffraction angles of all diffraction orders of the diffracted light are enlarged, single-ring Laguerre-Guss beams are obtained through the aperture diaphragm and are sent to the liquid crystal spatial light modulator, the Bessel beams which are off an axis and are transmitted around the axis in a screw mode are generated by passing through the axicon, and the Bessel beams are irradiated to the CCD camera to obtain light distribution. The optical system generating the screw type Bessel beams and the generating method achieve generation of the Bessel beams which are off the optical axis and are transmitted around the optical axis in the screw mode.

The invention discloses a space phase compensation system in orbital angular momentum optical communication, and a method thereof, and relates to the liquid crystal space spatial modulation technology, and in particular to phase compensation of vortex beams in space optical communication. The system comprises a light source, a modulation OAM, mode multiplexing, a free space, a demodulation OAM andcoherent detection, which communicate with each other in sequence; and any beam phase reflected by a liquid crystal spatial light modulator is compensated on a sending end and a receiving end by using an iterative phase recovery algorithm, thereby improving the imperfect state of the symmetry of the vortex beams caused by atmosphere turbulence, improving the quality of the beams and facilitatingthe subsequent utilization and transmission.Compared with the prior art, the space phase compensation system disclosed by the invention realizes the phase distortion existing in a stepwise correctionspatial optical communication system, (2) improves the quality of the generated vortex beams and the quality of receiving demodulation to a certain extent,comprehensively improves the signal to noiseratio of the whole system and reduces the bit error rate; and the space phase compensation system is simple in structure and is easy to implement.

The invention discloses a confocal transverse scanning device and a confocal transverse scanning method based on a reflection type liquid crystal spatial light modulator, belongs to the technical field of optical precision measurement, and in particular relates to a confocal microscope and a scanning method thereof. The reflection type liquid crystal spatial light modulator is adopted to take the place of a transverse scanning mechanism in a conventional confocal transverse scanning device; and by changing the phase driving spectrum loaded by the reflection type liquid crystal spatial light modulator, the two-dimensional deviation of a light beam is realized, and the non-mechanical transverse scanning is realized. Due to such design, the microscope and a tested object both do not need to be transversely moved, but the transverse light beam scanning on the tested object is realized; not only is the precise and complex control on a three-dimensional micro-displacement platform avoided, but also the scanning precision and the repetitiveness are improved; and particularly, the effect is more remarkable for easily-deformed samples, so that the types of measured samples are widened.

An interference type double-imaging measurement device for multiple parameters of a liquid crystal spatial light modulator relates to the technical field of photo-electricity test. The invention solves the problem that the characteristic parameter measurement device of the existing liquid crystal spatial light modulator can not satisfy the requirement of multi-parameters measurement. By introducing a double-imaging system in a Twyman-Green interference light path, the invention integrates the double light path interference and common path interference into a device. Input light enters in a first dispersion prism through a beam expanding lens and a polarizer. Transmitted light is modulated and reflected by the liquid crystal spatial light modulator and then reflected by a reflecting mirror through a shutter. The two-way lights enter in a second imaging system through a second dispersion prism after passing through the first dispersion prism and an analyzer. After reflected by the liquid crystal spatial light modulator, the transmitted light can also directly enter in a first imaging system through the first dispersion prism, the analyzer and the second dispersion prism. The invention realizes the measurement of multi-parameters by using the double-imaging system to respectively detect phase and strength. The measurement device is applicable to the measurement process of multi-parameters of the liquid crystal spatial light modulator.

The invention relates to a device for measuring parallelism of sight axis and reception axis of a laser range finder based on liquid crystal modulation, which belongs to the technical field of optical precision measurement. The device comprises an off-axis parabolic mirror, a liquid crystal spatial light modulator, an integrating sphere, a visible light source, an optical fiber A, a laser delay module, an optical fiber B and a coupler, wherein the liquid crystal spatial light modulator is disposed on the focal plane of the off-axis parabolic mirror; the liquid crystal spatial light modulator, the integrating sphere, the optical fiber A, the laser delay module, the optical fiber B and the coupler are sequentially disposed behind the focal plane, and the coupler is connected with a laser emitter; and the visible light source is connected with the integrating sphere. The detection device uses the liquid crystal to perform electro-optical modulation to generate surface target for optoelectronic scanning. The invention can be used for rapid detection of the parallelism of sight axis and reception axis of the laser range finder in both indoor and outdoor environments; and has the advantages of high measurement success ratio, high precision and portability.

Disclosed is a method for generating random column vector polarized beams by a single liquid crystal spatial light modulator. A light beam generating system is composed of a laser device, a liquid crystal spatial light modulator, a battery of lenses, a lambada / 2 wave plate, lambada / 4 wave plates, a horizontal polarizing film, a triple prism, a reflector, a beam zooming device and the like. Linearly polarized light in a random polarization direction is incident, light beam amplification is achieved after the battery of lenses, the lambada / 2 wave plate can be used for adjusting the polarization direction of the linearly polarized light, horizontal line polarized beams are guaranteed to be obtained through the polarizing film transmitted in a horizontal direction, and beam intensity can also be adjusted by combining the lambada / 2 wave plate and the polarizing film. The horizontal line polarized beams pass through the liquid crystal spatial light modulator, then achieve space phase modulation, finally pass through a first lambada / 4 wave plate, the liquid crystal spatial light modulator and a second lambada / 4 wave plate in sequence by being reflected by the triple prism and the reflector, controls the polarization state of space light beams and generates the random column vector polarized beams. When the two lambada / 4 wave plates are removed, vortex beams can be generated. The method for generating the random column vector polarized beams by the single liquid crystal spatial light modulator is low in cost, high in purity, multiple in variety of generated light beams, simple in structure, easy to operate and control and wide in applied range.

A system for producing spatially modulated monochrome or color light having gray scale includes an active matrix liquid crystal spatial light modulator having light modulating means including (i) a layer of ferroelectric liquid crystal material which is designed to switch between ON and OFF states and (ii) active matrix means including VLSI circuitry for dividing the layer of liquid crystal material into an array of individual liquid crystal pixels and for causing each of the pixels of liquid crystal material to modulate light individually by switching between the ON and OFF states in a way that depends upon the data which the VLSI circuitry is written. The system also includes illumination means having a light source for directing light from the source into the pixel-divided layer of ferroelectric liquid crystal material in a specific way. And finally, the system includes means for writing the VLSI circuitry with preselected data in accordance with a particular data ordering scheme such that the circuitry, in response to the written data, causes the pixels of liquid crystal material to individually switch between their ON and OFF states and therefore modulate light from the source in a way which, depending upon the data, produces a specific overall pattern of gray scale light.

A liquid crystal device display (20) has a backlight unit (56) for providing illumination, a rear polarizer (50b) disposed proximate the backlight unit (56) for receiving the incident illumination and transmitting substantially polarized illumination, a liquid crystal spatial light modulator for forming a display beam by selective, pixel-wise modulation of the polarization of the substantially polarized illumination, and a reflective polarizer (52a) disposed between the liquid crystal spatial light modulator and a front polarizer (50a).

The invention discloses a soft matter comprehensive measuring device based on novel hybrid optical tweezers, comprising a laser, a first planoconvex spotlight, a second planoconvex spotlight, a first reversible reflector, a first reflector, a liquid crystal spatial light modulator, a second reversible reflector, a third planoconvex spotlight, a fourth planoconvex spotlight, a first dichroic mirror, a microscope objective, a two-dimensional electric platform, a halogen lamp, a microscope imaging tube mirror, a second dichroic mirror, a position detector imaging lens, a position detector, a camera and a computer, wherein the device can effectively work in the modes of high precision single optical tweezers and holographic optical tweezers, and the computer is respectively connected with theliquid crystal spatial light modulator, the camera and a position sensor signal inception system through signal lines. According to the invention, the measurement of simultaneous capture operation and interaction of a plurality of particles in liquid phase can be realized, and the measurement of broadband rheology characteristics of a microfluid by using a single particle probe can be realized.

The invention discloses a resolution-adjustable wavelength selection switch based on a phase grating array and a control method. The resolution-adjustable wavelength selection switch comprises a one-dimensional single mode fiber array, a microlens array, a polarization adjusting prism, a double-glued optical Fourier transformation lens, a transmissive phase diffraction grating array, a cylindrical mirror, a liquid crystal spatial light modulator and a graph loading control system. The transmissive phase diffraction grating array is adopted, difference in chromatic dispersivity of transmissive phase diffraction gratings different in period is utilized, and wavelength range of parallel beams finally imaged on the liquid crystal spatial light modulator and wavelength control accuracy determined by a single pixel unit can be changed by switching the transmissive phase diffraction gratings having different periods, so that switching and adjusting of working wavelength range and wavelength resolution of the wavelength selection switch are realized, and the wavelength selection switch can be used for processing large-bandwidth high-speed signals in backbone networks.

The invention discloses a dynamic local amplification high resolution imaging system, belongs to the technical field of an optical apparatus and solves technical problems of conflicts between a largeview field of long-distance target detection and high resolution imaging, the complex system structure and relatively high cost existing in an optical imaging system in the prior art. The system comprises an imaging object lens, a small aperture local magnifying lens group, a relay image rotation lens set, a transmission type liquid crystal spatial light modulator (SLM) and a detector image plane,wherein the small aperture local magnifying lens group and the transmission type liquid crystal spatial light modulator (SLM) are used for realizing local area amplification and high resolution imaging. The system is advantaged in that the small aperture local magnifying lens group is arranged near the intermediate image plane position, two-dimensional scanning in the x and y directions is carried out through the small aperture local magnifying lens group, one-time image plane different position dynamic local amplification is realized, through the relay lens set, local amplification images atdifferent positions are acquired on the detector image plane, the system structure is simple, cost is low, and dynamic local amplification in the large view field scope can be realized.

The invention belongs to the technical field of optics, and particularly relates to a spatial phase shift dynamic interferometer based on a liquid crystal spatial light modulator and application of the spatial phase shift dynamic interferometer. The spatial phase shift dynamic interferometer based on the liquid crystal spatial light modulator comprises a He-Ne laser, a first pinhole filtering, a first collimation and beam expanding system, a lambda / 2 wave plate, a polarizing beamsplitting prism, a first lambda / 4 wave plate, a second collimation and beam expanding system, a second pinhole filtering, a polarizing film, the liquid crystal spatial light modulator, a second lambda / 4 wave plate, a standard spherical mirror, a measured mirror, a polarization analyzer, an imaging system, a third pinhole filtering and an optical detector, dynamic testing of an aspheric surface member and a free-form surface member is realized through coded modulation of SLM, the SLM is used for replacing a tinypolarization phase shift array to realize spatial phase modulation, the adjustment is simple, the tiny polarization phase shift array is not required, and the difficulty is greatly reduced. Accordingto the spatial phase shift dynamic interferometer based on the liquid crystal spatial light modulator and application of the spatial phase shift dynamic interferometer, the function of real-time dynamic display is achieved, low energy consumption, easy control and high speed are achieved, the spatial resolution ratio is easier to improve, and high-precision measurement is realized.

The invention provides a liquid crystal phased array-based laser radar system, and relates to the technical field of laser phase control. By the liquid crystal phased array-based laser radar system, the problem that incident light and emergent light are separated by a light splitter in an existing light path and the light intensity loss can be caused by introduction of the light splitter so that the application of a beam deflection system is limited are solved. The liquid crystal phased array-based laser radar system comprises a central processing unit, a laser emission system and an echo receiving system, wherein the laser emission system comprises a laser A and an emission light path, the emission light path comprises a beam expansion collimation system A, a refined deflection system, aone fourth wave plate and a rough deflection system, the refined deflection system comprises a one second wave plate, a liquid crystal spatial light modulator (LCSLM) and a DSP controller, the rough deflection system comprises a liquid crystal polarization rotator, a liquid crystal spatial light modulator (LCPG) and a polarization grating controller, and the echo receiving system comprises a fieldprogrammable gate array (FPGA), an MPPC and a receiving light path. An oblique incidence mode is employed, an included angle between light irradiating the liquid crystal spatial light modulator and emergent light is increased, the light path is simplified, the system volume is reduced, the light intensity loss caused by the light splitter is also reduced, and the application range of the liquid crystal spatial light modulator is expanded.

The invention discloses a three-dimensional vector beam and a generation method and apparatus thereof. According to the provided three-dimensional vector beam, the optical field distribution is similar to the Bessel beam; and the cross section polarization-state distribution of the light beam changes with the change of the transmission distance and changes periodically. Within one spatial period, the polarization state of the beam changes from radial polarization to angular polarization alternately. Generated light beams can have various polarization-state distribution modes; and thus compared with the existing vector beam in single polarization-state distribution, the provided vector beam has the greater application value. According to the generation apparatus for the three-dimensional vector beam, generation of three-dimensional vector beams with different orders can be realized only by changing holographic grating loaded on a liquid crystal space light modulator without the need to adjust any other optical element again, so that the operation becomes simple and convenient.

The invention provides a novel purely electric control two-dimensional light beam deflection method and device. The method and device can realize angular deflection in a two-dimensional range, and fills the blank in two-dimensional light beam deflection field of the existing space light modulator based on a single liquid crystal. According to the invention, the quasi-continuous deflection controlof the light beam can be conveniently realized in the two-dimensional range by adopting the space light modulator based on the single liquid crystal and using a novel driving principle; therefore, the light beam deflection is convenient for operation and high in precision and has the advantage of uniform and quasi-continuous angle distribution. Two parameters alpha'and beta'generating a phase image are both continuous and controllable parameters; therefore, the problem that light beam deflection angles are discrete and not distributed uniformly in the traditional method is solved. The invention provides a simple method for realizing the deflection of the two-dimension light beam, and fills the blank of the traditional method in the two-dimension light beam deflection field.

The invention discloses a spatial light modulator modulation performance testing device and method based on a 4F interference system. The testing device comprises a laser, a polarizing film, an objective lens, a needle hole, an optical lens, a beam splitter prism, a reflection-type liquid crystal spatial light modulator, a reflector, two Fourier lenses, a CCD camera and a computer. The two Fourier lens are combined to form the 4F interference system, and pixels of the spatial light modulator correspond to pixels of the CCD camera in a one-by-one mode. According to spatial light modulator modulation performance testing device and method, the phase modulation performance of the spatial light modulator can be tested, mutual crosstalk among pixels of the spatial light modulator can be tested, actual phase modulation amount of SLM pixels is measured after phase distribution with given loading phase types is carried out, the deviation between the actual phase modulation amount and a theoretical value is analyzed, the corresponding correction method is studied, the actual phase modulation amount of the SLM pixels meets the theoretical value, and accordingly the holographic photoelectric reproductive image quality is improved.

A method for improving liquid crystal spatial light modulator (10) uniformity is disclosed wherein an original code value (40) is obtained for a first pixel and a conditioned code value (50) is assigned to the first pixel. The conditioned code value is determined by characterizing the luminance response of a sample pixel of the spatial light modulator and defining an interpolation zone (18) for code values bounded between a minimum luminance code value and a threshold code value (16) for the sample pixel. The threshold value corresponds to a luminance level at which there is a generally linear relationship of luminance to code values. If the original code value lies within the interpolation zone, an interpolated value is calculated as the conditioned code value. The pixel of the spatial light modulator is modulated according to the conditioned code value.

The invention discloses a device and method for carrying out parallel processing of scattering net points of light guide plates through femtosecond lasers. The device comprises a light guide plate transmitting and locating device, a light guide plate processing center device, a heat removal and dust removal device, a femtosecond laser holography parallel processing system and a control center. The light guide plate transmitting and locating device comprises a light guide plate transmitting mechanism, an adsorption device and a grating locating sensor. The light guide plate processing center device comprises a complete machine bridge, a supporting plate and ball screw feed devices in the direction X and the direction Y. The femtosecond laser parallel processing system is a beam splitting and conduction device used for emitting a laser beam through a femtosecond laser device and comprises the femtosecond laser device, light path transmitting and controlling equipment, a spatial light modulator (SLM) and a microscope and monitor system. According to the device and method, the liquid crystal spatial light modulator (LCSLM) is utilized for locating a computer generated hologram (CGH), parallel processing of multiple light beams can be achieved at a time, the processing speed can be effectively increased, the processing efficiency is remarkable, the processing time is shortened, and the processing cost is greatly reduced.

The invention discloses a method for realizing varifocal lens based on a liquid crystal space optical modulator. The method comprises the following steps: according to the phase modulating principle of the liquid crystal space optical modulator, controlling the liquid crystal space optical modulator to modulate an incident light wave to generate a kinoform, diffracting the incident light wave into a converging spherical wave, and changing radius and zone number of a Fresnel zone plate in the kinoform to realize the variable focus of a program-control varifocus imaging system established by the liquid crystal space optical modulator. The method provided by the invention can be used for improving the automatic varifocus precision and the varifocus response speed of the varifocus imaging system, so that the focal distance of the lens is variable and easy to control.

The invention discloses a large-port-number wavelength selection switch based on an optical beam expanding unit and a control method thereof. The large-port-number wavelength selection switch comprises a one-dimensional single mode fiber array, a microlens array, a polarization adjusting prism, the port optical beam expanding unit, a double-glued optical Fourier transformation lens, a transmissive phase diffraction grating, a cylindrical mirror, a liquid crystal spatial light modulator and a liquid crystal graph loading control system. By adding the port optical beam expanding unit into an optical system, maximum allowable width of the one-dimensional single mode fiber array is effectively expanded, so that limitation effect of optical pointing ability of the liquid crystal spatial light modulator on number of fiber ports which can be contained by the wavelength selection switch is eliminated thoroughly, number of output fiber ports in the wavelength selection switch is substantially increased, and fold increase of the number of ports of the wavelength selection switch is realized. The large-port-number wavelength selection switch is simple in structure, easy to manufacture, low in cost and capable of realizing substantial increase of the number of the output ports.

A confocal axial scanning device and a confocal axial scanning method based on a reflection type liquid crystal spatial light modulator relate to a confocal microscope and a scanning method of the confocal microscope, which solve the problems that in an existing axial scanning device and a method, the device is complex in structure and a sample is poor in repeatability of measurement due to the fact that defocus of a measured object is achieved by means of a lens or movement of the measured object along an axial direction. By means of the confocal axial scanning device, the reflection type liquid crystal spatial light modulator is added between a polarization beam splitter and the lens of the existing device, an axial scanning mechanism in a traditional confocal axial scanning device is eliminated simultaneously, and the reflection type liquid crystal spatial light modulator is utilized to replace the axial scanning mechanism. The confocal axial scanning method adopts a mode of utilizing a computer to directly modulate a phase gray-scale figure to adjust wavefront of a light wave in front of the lens so that zoom is achieved, and axial scanning to the measured object can be achieved without axially moving the measurement lens and the measured object. The confocal axial scanning device and the confocal axial scanning method based on the reflection type liquid crystal spatial light modulator are applied to the confocal microscope and the scanning method of the confocal microscope.

The invention discloses a device for compressing a chirp entangled photon pair. The device comprises a continuous laser device, wherein a first convex lens, a first nonlinear crystal, a second convex lens, a first light filter, a first collimator, a liquid crystal-spatial light modulator, a second collimator, a third convex lens, a second nonlinear crystal, a fourth convex lens, a second light filter, a fifth convex lens, a single-photon detector and a photon counter are sequentially arranged on a light path at one side of the continuous laser device. The invention further discloses a compressing method adopting the device. According to the device and the method for compressing the chirp entangled photon pair disclosed by the invention, the compression effects are the same as that of a traditional phase compensation scheme; and the defects that the compression result is limited by the dispersive medium length and the dispersive higher-order term and the loss is generated when an entangled photon signal passes through a dispersive medium in the traditional phase compensation scheme are overcome.

The invention discloses an orbital angular momentum (OAM) coherent demultiplexing device and a separation detection method. The device comprises a beam splitter for carrying out beam splitting on incident beams, a reflector for adjusting the light propagation direction and realizing an odd number of times of light reflection, a liquid crystal spatial light modulator for converting vortex beams with specific topological load to fundamental-mode Gaussian beams, a coherent separation unit for realizing separation between an OAM channel with certain specific topological load and other OAM channels, a phase shifter for realizing phase shift pi of beams, a photoelectric detector for realizing photoelectric conversion, and a differential circuit for subtraction operation on current. The device of the invention is used for realizing OAM coherent separation detection. The novel device provided by the invention can enhance the detection performance of the existing free-space optical orbital angular momentum multiplexing communication system and the transmission distance, and an important application prospect is realized in fields of optical communication in a vortex field and information processing.

The invention relates to a method for machining a butterfly-shaped nanometer gap through coordinative shaping of femtosecond laser phase position amplitude and belongs to the technical field of laserapplication. A reflecting type phase position type liquid crystal spatial light modulator can carry out phase position modulation on incident light, thus reflected light has designated phase positiondistribution on space, meanwhile, a narrow gap is utilized for carrying out amplitude shaping on light beams obtained after phase position shaping, and thus coordinative shaping of the phase positionand the amplitude of the initial light beams is achieved. The light beams obtained after coordinative shaping pass through a focusing objective lens to be focused, and multi-light-point light beams with different structure parameters are formed. The generated multi-light-point light beams are utilized for machining a designated material, material removal can be achieved in the area with strong light intensity, the material is kept in the area with the weak light intensity, and thus the butterfly-shaped nanometer gap can be obtained. According to the method, a light path needing to be set up issimple, use is convenient, a mask and vacuum environment are not needed, the machining cost is low, the machining efficiency is high, and the method plays an important role in the machining field oflaser micro nanometer structures.

The invention relates to a Littrow-structure tunable external-cavity laser and a mode-hopping-free sweep-frequency regulation method thereof, belonging to the technical field of laser tuning. The problem that the existing Littrow-structure external-cavity laser cannot realize large-scale mode-hopping-free tuning is solved. The Littrow-structure tunable external-cavity laser comprises a semiconductor laser, a liquid crystal spatial light modulator and a blazed grating. The mode-hopping-free sweep-frequency regulation method comprises the steps that laser beams which are emitted by the semiconductor laser are enabled to pass through the liquid crystal spatial light modulator and then to be incident onto the blazed grating, first-order diffracted light which passes through the blazed grating and returns back along the original path forms resonance between the inner cavity and the outer cavity of the tunable external-cavity laser, and finally the light emerges from the zero order of the blazed grating; and the blazed grating is rotated around an axis point O, the voltage of the liquid crystal spatial light modulator is changed at the same time to change the refractive index of the liquid crystal spatial light modulator and the mode-hopping-free sweep-frequency regulation of the tunable external-cavity laser is realized during tuning by rotating the blazed grating. The mode-hopping-free sweep-frequency regulation method is applicable to the regulation of lasers.