54results about How to "Shorten cavity length" patented technology

The invention discloses a spectrum beam combination device for realizing twice diffraction by using the transmission grating of a plated reflecting film. The spectrum beam combination device comprises a semiconductor laser unit light source, a slow-axis collimated column lens, a conversion lens, a transmission grating and an output coupling mirror. The transmission grating of the back plated reflecting film is used as a diffraction element, namely the reflecting film is plated at the back of a grating surface, so that the dispersive power of the grating can be doubled by an incident beam through the diffraction of the transmission grating twice. According to the spectrum beam combination device, the restriction that the dispersive power of the diffraction grating is limited in traditional spectrum beam combination is overcome, the number of beam combination elements can be increased in the gain line width of the material and the high-efficiency diffraction wavelength range of the grating, and the output power is obviously improved, or the length of a resonant cavity can be shortened when certain output spectrum width is guaranteed, so that the structure of a laser unit is compacter, and the mode of the laser unit is stabler.

A passively mode-locked picosecond laser device comprising a pump source, a laser crystal, a laser cavity, a mode-locked output structure is provided. In the device, the pump source is placed at the side of the incident end surface of the laser crystal; the laser cavity includes a plane reflective mirror and a first plano-concave mirror, the reflective mirror is placed opposite to the concave surface of the plano-concave mirror and located on the position of the focal radius of the plano-concave mirror. The normal direction of the reflective mirror and the axis of the plano-concave mirror form a small angle therebetween; the laser generated from the laser crystal oscillates in the laser cavity, and output through the mode-locked output structure. The device uses a stable cavity design of the equivalent confocal cavity, which can increase the optical path, reduce the repetition frequency, and significantly reduce the cavity length and volume.

A single-mode quantum cascaded laser linear array structure is characterized in that: the structure comprises a substrate, a plurality of crestiform units, an isolation layer, an upper ohmic contact layer and a lower ohmic contact layer. The plurality of crestiform units are sequentially arranged on the substrate longitudinally to form a crestiform structure column; the isolation layer is arrangedon the surfaces of the plurality of crestiform units and the substrate, and is disconnected on the upper surfaces of the plurality of crestiform units to form an electrical injection window; the upper ohmic contact layer is arranged on the isolation layer and the electrical injection window; and the lower ohmic contact layer is arranged on the lower surface of the substrate.

The invention discloses a frequency doubling self-regulating Q green laser inside a double-doped chrome yttrium aluminum garnet composite photassium titanyl phosphate cavity,and relates to a green laser. The self-regulating Q green laser is provided with a pumping source, a micro lens, a first column-shaped lens, a second column-shaped lens and a laser working medium Cr, Nd:YAG/KTP composite crystal. The pumping source, a micro lens, the first column-shaped lens, the second column-shaped lens and the laser working medium Cr, Nd:YAG/KTP composite crystal sequentially are arrayed on a same plain shaft from front to back. Anti-reflection film and a high-reflective film are plated on the rear surface of the laser working medium Cr, Nd:YAG/KTP composite crystal to serve as a back cavity lens of the laser cavity. High-reflective film and anti-reflection film are plated on the front surface of the laser working medium Cr, Nd:YAG/KTP composite crystal of the laser cavity. The number of optical elements used for the laser is small, the production cost is low, the structure is simple and compact, and the laser is convenient to produce and assemble and operate and use by a non-professional person.

A wavelength variable laser smaller in size than the conventional one can be achieved by arranging a gain chip, an etalon filter and a fifth reflective mirror on an AlN submount and longitudinally integrating the gain chip in which a 45° mirror and a lens are integrated and the etalon filter. A laser cavity has a structure in which light passes through an active layer from a first reflective mirror realized by an end surface of the gain chip, is reflected by the 45° mirror at an angle of 90° and then passes through the lens. The light having passed through the lens is converted into parallel light, passes through the etalon filter and reaches the fifth reflective mirror and is then reflected. The reflected light returns through the same optical path and reaches the first reflective mirror realized by the end surface of the gain chip.

The invention discloses a three-dimensional Dirac semimetal diffraction grating. Three-dimensional Dirac semimetal materials are free from gap and linear in energy dispersion relation and serve as scribed line materials. The working wavelength of the grating covers infrared areas of 2-6 micrometers, various nonlinear optical parameters can be adjusted and controlled, a device comprises a diffraction grating function layer and an optical element, the diffraction grating function layer is made of the three-dimensional Dirac semimetal materials, and the optical element is used for bearing the function layer. The three-dimensional Dirac semimetal diffraction grating is provided with a diffraction grating device based on three-dimensional Dirac semimetal, and the diffraction grating device has a high reflectance mode and a low reflectance mode. The invention further provides a particular scheme of an infrared pulse laser generating tunable wavelength by the aid of saturable absorption (or ultra-fast optical switch) characteristics of the three-dimensional Dirac semimetal diffraction grating.

The invention discloses a helium-neon laser treatment device and a manufacturing method thereof. In the device, 2-6 flat helium-neon laser tubes are arranged in parallel; after being emitted by the laser tubes, laser light is reflected by a group of 45-degree plane mirrors; reflected light beams get close in parallel, and enter an optical fiber coupler consisting of a coupler body, a lens, an optical fiber positioning socket and an optical fiber plug inserted into the optical fiber positioning socket; one end of the optical fiber plug is connected with an optical fiber; and a main discharging circuit in a laser power supply consists of a voltage doubling circuit and a high-voltage current regulating circuit. In the helium-neon laser treatment device, multiple beams of laser light are coupled to a quartz optical fiber of which the core diameter is less than 0.6 millimeter for outputting and irradiating on a focus of infection. The helium-neon laser treatment device has the advantages of convenience for using, working stability and reliability, high output power and high coupling efficiency.

The invention discloses a double-cavity interconnection V shape structure single-direction overlapping output quasi-cw green light laser which uses two semiconductor laser pumped components with same type pump two Nd:YAG crystals from side surface (semiconductor laser pumped Nd:YAG mode). Two modes are set in a plane concave V shape resonant cavity and a plane concave straight cavity, and form two beam 1064nm basic frequency lights with stabile operation, generate two beam frequency doubled lasers via acousto-optic Q switch and frequency doubled crystal, and reach plane folding mirror, single-direction overlapping output via plane folding mirror, and gain 532nm green light with average power as high as 206W. The laser has stable property, high frequency doubled efficiency, and is wide used in laser material processing, light storage, laser full-color display, laser medicine, scientific research, communication, national defence and amusement etc.

The invention provides a D-shaped fiber-based cross-polarization beat laser and a sensor. The laser comprises a pump laser, a wavelength division multiplexer connected with the pump laser, a first fiber Bragg grating, one end of which is connected with the wavelength division multiplexer, a second fiber Bragg grating, one end of which is connected with an output fiber, and an erbium-doped D-shaped fiber which is encapsulated between the other end of the first fiber Bragg grating and the other end of the second fiber Bragg grating, wherein the first fiber Bragg grating, the second fiber Bragg grating and the erbium-doped D-shaped fiber are integrated on one fiber. The distributed fiber grating is adopted as a reflector to form an ultrashort resonant cavity, and the cavity length can be effectively shortened, so that the laser can run in a single-longitudinal-mode state, and the generated laser has good coherence. The D-shaped fiber is used as the body of the resonant cavity, the constraining performance of the resonant cavity on light can be reduced, and part of the transmitted light is leaked from one side to form an evanescent field which is sensitive to external environment changes, so that induction of a specific parameter can be realized.

The invention relates to a yellow-light self-Raman laser. The yellow-light self-Raman laser comprises a laser diode, a coupling optical fiber, a condensing lens, an input cavity lens, a self-Raman laser crystal, a Q adjusting device and an output cavity lens which are all sequentially arranged in the exit direction of an optical path, wherein the self-Raman laser crystal is a neodymium-doped calcium oxide borate salt crystal, the neodymium-doped calcium oxide borate salt crystal comprises neodymium-doped YCOB Nd:YCOB or neodymium-doped GdCOB Nd:GdCOB, and the neodymium ion doping concentration of the neodymium-doped YCOB Nd:YCOB or the neodymium-doped GdCOB Nd:GdCOB of the self-Raman laser crystal ranges from 0.1 at% to 30 at%. According to the yellow-light self-Raman laser, the neodymium-doped calcium oxide borate salt crystal serves as the self-Raman laser crystal, and therefore both laser gain mediums and Raman gain mediums can be obtained, the self-Raman effect can also be achieved, a frequency doubling crystal is reduced compared with a traditional self-Raman laser crystal, and the yellow-light self-Raman laser is smaller in size, more compact in structure, lower in cost, more stable in operation and suitable for large-scale batch industrial production and has good market application prospect.

The invention relates to a micro-optical cavity, in particular to a method for manufacturing an ultra-stable ultra-high-fineness micro-optical cavity, which solves the problem that the traditional micro-optical cavity cannot meet the measurement requirements due to lower fineness. The method for manufacturing the ultra-stable ultra-high-fineness micro-optical cavity comprises the following steps of: selecting two lenses; constructing an air purifying device connected with a closed operation space; bonding the two lenses with two flaky piezoelectric ceramics together to form the micro-optical cavity; calculating cavity length and fineness of the micro-optical cavity; and placing the micro-optical cavity in a vacuum gas chamber and maintaining vacuum degree to be 10-80Pa. The fineness of the optical cavity manufactured by the manufacturing method disclosed by the invention can reach 330,000 so that the ultra-stable ultra-high-fineness micro-optical cavity can be widely suitable for use in the fields of environment monitoring, material analysis, biological medicine, food sanitation, safety production and information technology.

The invention relates to an optical fiber annular chamber active Q-adjust laser, which comprise pump source, optical fiber wavelength-division multiplex device, increment optical fiber, sound-optical fiber modulator, and optical fiber couple output device. Wherein, two inputs of wavelength-division multiplex device are 980nm and 1060nm; the 980nm end is connected to the output of pump source; the 95.03 end of optical fiber couple output device is connected to the 1060nm end; the 4.97 end of output device is the laser output. The invention has compact structure, small volume, low consumption, and high-quality laser beam.

The invention provides a high-efficiency laser multi-pass amplification device. The device comprises two pumping source units, a gain medium and a seed light reflection mirror group. Each pumping source unit comprises a pumping source and a pumping light reflecting mirror. The seed light reflection mirror group comprises a first seed light reflecting mirror, a second seed light reflecting mirror and a third seed light reflecting mirror. The gain medium is cylindrical, an upper bottom surface of the gain medium is provided with a first film layer, a lower bottom surface is provided with a second film layer, and a side surface is provided with threads. The pumping source unit is located at an upper bottom surface side of the gain medium, and a reflecting surface of the pumping light reflecting mirror faces towards an upper bottom surface of the gain medium. The seed light reflecting mirror group is located on the lower bottom surface side of the gain medium. The first film layer reflectsseed light and transmits pump light, and the second film layer transmits the seed light and reflects the pump light. By increasing a frequency of the pump light penetrating through the gain medium, transverse parasitic oscillation can be greatly reduced while the output efficiency of an amplifier is kept.

The invention discloses a He-Ne laser tube with a flat inner cavity. The He-Ne laser pipe comprises a flat discharge tube, mirrored tubes, dielectric film reflecting mirrors, a cathode bulb and an anode bulb, wherein an oxide cathode filament and a cathode lateral rod are arranged inside the cathode bulb, an anode is arranged in the anode bulb, the round mirrored tubes are respectively arranged at two ends of the flat discharge tube, and the dielectric film reflecting mirrors are respectively stuck to the two ends of each mirrored tube. The He-Ne laser tube disclosed by the invention has the advantages of high output laser power, convenience for user usage, long service life and the like. The perpendicularity of the reflecting mirrors serving as an optical cavity and a tube axis of the flat discharge tube is detected by adopting an He-Ne laser intra-cavity oscillation method, a spherical concave-surface reflecting mirror is rotated around the tube axis so as to make an intra-cavity oscillation mode filed in a long strip shape, the length-to-width ratio of the long strip shape is more than 3:1, and thus, the position of the spherical concave-surface reflecting mirror is determined.By utilizing the detecting method, the yield of manufacture is obviously increased.

The invention discloses an end and side mixed pumping Tm laser, and relates to a laser, in particular to an end and side mixed pumping Tm<3+>:YLF laser. Pumping light of 792 nm is split into two beams to the side of a crystal from the end by using two 45-degree beam splitters; a 45-degree 792 nm membrane series totally reflecting mirror is adopted to turn a light path of the side pumping light; a pumping spot is reduced through a beam shrinkage mirror to perform pumping on the side of the crystal; and thus, a structure for pumping the end and the side simultaneously by an LD (Laser Diode) is formed. In design of the entire machine, focusing is completely avoided, the cavity length is reduced, and the threshold is favorably reduced. The method is complete and accurate, is suitable for the technical research of Tm<3+>:YLF laser pumping and is applied to the fields such as electro-optical countermeasure, laser radar and laser medical treatment.

The invention relates to a single end-pumped high-power narrow-pulse fundamental mode ultraviolet laser and a working method thereof. The laser includes a pump source, a coupling lens group, a plano-convex lens, a laser crystal, a Q-switching device, a first flat mirror, a triple frequency crystal, a frequency doubling crystal and a second flat mirror; one end face of the triple frequency crystalis cut into the brewster angle. The laser adopts plano-convex V-cavity design, which increases the internal mold volume of a resonant cavity and the number of inverted particles which can be utilizedin the laser crystal. The design can compensate for the thermal lens effect during high-power operation, so that the laser is in a stable region at high power, the stable running of the laser under the single-ended high power is achieved, and the volume and cavity length of the laser are reduced to facilitate narrow pulse output. The design of a plano-convex cavity is beneficial for suppressing multi-mode generation, the laser has a mode selection function, and the beam quality of fundamental light, frequency doubled light and ultraviolet light of the laser is improved.

It is an object of the present invention to provide a tunable high-power ultrashort pulse fiber laser, A passively mode-locked fiber laser with short resonator structure generates ultrashort pulsed laser signal with high repetition rate, The output signal is preamplified into the second acousto-optic pulse selection module to carry out the second pulse selection, and the frequency adjustable rangeis greatly increased. The first pulse selection is realized by the acousto-optic pulse selection module. The output signal is amplified to high power by the MOPA structure of pre-amplification and two-stage main amplification, and then the high power ultrashort pulsed fiber laser with wide repetition rate range is obtained.

The invention discloses a method and a device for generating ultrashort pulses with high pulse repetition frequency on the basis of graphene microcavity mode locking. A graphene microcavity with high nonlinearity, narrow linewidth, larger free spectral range, larger modulation depth and small non-saturable absorption loss is adopted, the repetition frequency of the pulses is increased with a four-wave mixing effect of filtering, the stability of mode-locked pulses is improved through combination with a saturable absorber for inhibiting spontaneous radiation noise and narrowing pulse width, and pulse signals with hundreds of GHz of repetition frequency, hundreds of fs of pulse width and low jitter are generated. Implementation of laser promotes development of optic fiber laser with high pulse repetition frequency and low pulse width.

The invention discloses a fiber laser convenient to generate high repetition frequency pulse laser light. A nonlinear loop mirror is adopted for polarization-maintaining mode locking; the mode lockingmechanism has the characteristics of being unique in mode locking point, not easy to unlock, free of an easy-to-wear device and broad in mode locking spectrum in comparison with traditional mode locking methods, such as an SESAM or an NPR, and is an ideal next generation fiber femtosecond laser seed source. By adopting a phase offset technology for built-in space, the fiber laser has the characteristics of being simple in structure and low in mode locking threshold in comparison with a traditional 8-shaped mode locking laser; the power requirement on an LD is reduced; and meanwhile, the service life of a whole device is prolonged. Furthermore, a negative dispersion single mode fiber and a positive dispersion fiber are also adopted for controlling dispersion, and addition of extra spatialdiscrete devices, such as a grating or a prism pair is avoided, so that the overall reliability is greatly enhanced.

The invention relates to an active Q-switched fiber laser pulse width adjusting system, and belongs to the technical field of photoelectrons. The system comprises a pump laser, a reflective fiber bragg grating, a doped fiber, a fiber power stripper, an acousto-optic fiber Q switch, an output fiber bragg grating, an acousto-optic fiber Q switch driver, a pump laser driving power supply and a control unit, the pump laser, the reflective fiber bragg grating, the doped fiber, the fiber power stripper, the acousto-optic fiber Q switch and the output fiber bragg grating are sequentially connected inseries; the pump laser driving power supply, the control unit and the acousto-optic optical fiber Q switch driver are sequentially connected in series; the pump laser driving power supply is communicated with the pump laser; the acousto-optic optical fiber Q switch driver is communicated with the acousto-optic optical fiber Q switch; according to the invention, the Q switch turn-on time is optimized, 10ns-level pulse width and higher power output can be obtained, and tunable pulse width output can be obtained through a table look-up method.