53results about How to "Lower laser threshold" patented technology

The invention relates to a self-frequency-doubling all-solid-state yellow-light laser. The laser comprises an excitation source, a focusing system, a self-frequency-doubling crystal and a laser resonator, wherein the self-frequency-doubling crystal is a ytterbium-ions-doped rare-earth calcium oxoborate crystal and is cut along the maximum direction of the effective nonlinear coefficient of a non main plane of the crystal; the excitation source is a 900-980nm light source; and the laser resonator is composed of an input cavity mirror and an output cavity mirror, the input cavity mirror and the output cavity mirror are each provided with a medium membrane for inhibiting vibration of a 1020-1080nm wave band, excitation light is subjected to collimating focusing and is injected into the self-frequency-doubling crystal through the input cavity mirror, the self-frequency-doubling crystal absorbs energy of the excitation light to generate fundamental frequency light in the laser resonator, and the fundamental frequency light carries out selection wavelength frequency multiplication through the self-frequency-doubling crystal so that 570-590nm yellow-light laser is output. The laser provided by the invention has the advantages of high output power, simple and compact structure, low cost, high temperature adaptability and the like.

The invention discloses a portable LIBS (Laser Induced Breakdown Spectroscopy) analyzer based on an optical fiber laser. The analyzer comprises a laser detection head and a main machine system, wherein the detection head comprises a laser output end, a diaphragm, a reflector, a dichroscope, a lens, a first micro displacement table, a second micro displacement table and a light collector; the main machine system comprises a spectrograph, a microcontroller, a portable PC (Personal Computer) and an optical fiber laser main machine. The analyzer disclosed by the invention uses the optical fiber laser as a laser light source and provides a novel spectrum collecting manner, the detection sensitivity is improved and the detection limit is reduced. When the analyzer is additionally provided with a polarizer, the analyzer further can inhibit interference of a continuous background in a plasma spectrum, so that the detection sensitivity is further improved. The analyzer provided by the invention is small in size, light in weight, convenient to carry, simple to operate and fast to analyze, can be used for real-time detection in a field environment or an industrial field, and is free from a vacuum environment and pretreatment on a sample. The size and electrical conductivity of the analyzed sample are not limited, so that the analytical efficiency is high.

The invention belongs to the technical field of micro-nano photons and laser, and particularly relates to a perovskite nano-structure plasma laser. A lead halide perovskite plasma laser comprises a lead halide perovskite nanosheet, an insulating dielectric layer and a metal substrate; the lead halide perovskite nanosheet, which is of a regular polygon structure, is located above the metal substrate; the insulating dielectric layer is located between the lead halide perovskite nanosheet and the metal substrate; and the ratio of the refractive indexes of the insulating dielectric layer and the lead halide perovskite nanosheet is less than 0.75. The perovskite nano-structure plasma laser has the characteristics of effective cavity feedback, low threshold value and adjustable wavelength.

The invention relates to an all-solid-state deep ultraviolet laser, in particular to a monocrystalline-diamond continuous wave tunable deep ultraviolet laser. The monocrystalline-diamond continuous wave tunable deep ultraviolet laser is provided with a 456nm single-frequency blue-light laser, a transverse mode matching lens, a first laser resonator mirror, a second laser resonator mirror, a third laser resonator mirror, a fourth laser resonator mirror, a laser gain medium, a frequency doubling crystal, a photodiode and a PDH (Pound-Drever-Hall) controller. The 456nm single-frequency blue-light laser, the transverse mode matching lens, the first laser resonator mirror, the frequency doubling crystal and the second laser resonator mirror are arranged on a first optical axis sequentially from left to right, and the third laser resonator mirror, the laser gain medium and the fourth laser resonator mirror are arranged on a second optical axis sequentially from left to right; the photodiode is located on the left rear side of the first laser resonator mirror, and the PDH controller is connected with the photodiode and the fourth laser resonator mirror; the first optical axis is parallel to the second optical axis. The all-solid-state deep ultraviolet laser is small in size, high in efficiency, long in service life, good in beam quality, easy for system integration and easily practical.

The invention discloses a one-way traveling wave annular cavity single-frequency quasi-three-level solid laser. The transmission length of an incident light beam corresponding to reflection in an active ion-doped crystal is smaller than the transmission length of a reflecting light beam in the active ion-doped crystal by using a thermal bonding laser crystal as a laser reflecting element in a cavity and selecting the position of the thermal bonding surface. The one-way traveling wave annular cavity single-frequency quasi-three-level solid laser can reduce the reabsorption loss experienced by laser on an unpumped transmission path when one-way pumping is adopted, thereby ensuring the compactness and stability of the laser, reducing the cost and complexity of the system and effectively improving the laser output performance during one-way pumping. The high linear polarization degree can be obtained in a resonant cavity further by selecting a simple and compact laser structure and the position of the thermal bonding surface so as to be beneficial to efficiently carrying out intracavity frequency doubling.

The invention discloses a two-micron-waveband low-threshold-value thulium-doped optical filer laser device for joint pumping of a fiber core and cladding and aims at solving the problem that an optical filer laser with the signal optical wavelength within the two-micron waveband is high in threshold value. The laser device is constituted by a pumping source, a gain medium and a resonant cavity, the pumping source is connected with the resonant cavity, the gain medium is located in the resonant cavity, and the resonant cavity is of a linear cavity structure or an annular cavity structure. If the resonant cavity is of the linear cavity structure, the pumping source is composed of a 790nm-waveband multimode pumping source body, a 1.5micron-waveband single-mode pumping source body and a pumping-signal beam bundler, and the resonant cavity is composed of two reflection-type optical fiber bragg gratings; if the resonant cavity is of the annular cavity structure, compared with the situation that the resonant cavity is of the linear cavity structure, the pumping source has one more wavelength division multiplexer, and the resonant cavity is composed of an optical fiber coupler, an optical fiber circulator and a reflection-type optical fiber bragg grating; the gain medium is thulium-doped double-clad optical fibers or thulium-and-holmium-doped double-clad optical fibers. By means of the two-micron-waveband low-threshold-value thulium-doped optical filer laser device, the laser threshold value of the two-micron-waveband optical filer laser device can be lowered, and generation of ASE is effectively inhibited.

The invention relates to the laser field, in particular to the laser structure. The laser comprises a pump cavity, a pump light source, an optical coupling system and other optical elements, wherein the pump cavity is provided with a light-admitting hole at the pump point, the other part of the pump cavity is all coated with a reflective coating, and the position of the pump light source corresponds to the light-admitting hole. An enclosed cavity which has high reflectivity to the pump light is formed by the pump cavity except the light-admitting hole, therefore, the pump light is reflected by a plurality of times in the enclosed cavity, and most of the pump light is absorbed by a laser gain medium except that a little bit of the pump light escapes from the light-admitting hole of the pump light. The structure of the invention is beneficial to improving the absorption efficiency of the gain medium on the pump light; can be applied to manufacture lasers with wide temperature operation range for reducing or eliminating the influence on the laser power due to the semiconductor laser wavelength shift caused by temperature change; and can reduce the volume of the laser gain medium and simultaneously reduce the laser threshold as the length of the laser gain medium can be shorter.

The invention concerns a gallery mode microdisc system for an electrically pumped optical source, the microdisc (1) being formed on one face of a substrate (2), the lower part of the microdisc being provided with an electrical contact referred to as the lower contact (4), the upper part of the microdisc being provided with an electrical contact referred to as the upper contact (6), the upper part of the microdisc being covered with a protective layer (3) of electrically insulating material, the central part (5) of the microdisc being electrically neutralised in order to prevent the passage of an electric current in said central part.

The invention discloses a 4-8[mu]m-pulse Raman all-fiber laser, and belongs to the field of the laser. The 4-8[mu]m-pulse Raman all-fiber laser comprises a light source, a gain fiber I and a gain fiber II that are connected in sequence, wherein a first resonant cavity and a second resonant cavity are formed in the gain fiber I; a multi-order stokes optical resonant cavity is formed in the gain fiber II; the first resonant cavity and the second resonant cavity are partially overlapped; and a pulse switch is arranged in a place, which is not overlapped with the first resonant cavity, in the second resonant cavity. According to the 4-8[mu]m-pulse Raman all-fiber laser provided by the invention, the 4[mu]m intermediate infrared Q-switched pulse and Raman Q-switched pulse laser with wavelength of greater than 4[mu]m can be efficiently realized under the normal temperature, so that the laser threshold value can be greatly lowered, the output efficiency can be improved, and the cost loss is relatively low; and in addition, the Raman all-fiber laser has the characteristics of easy integration, facilitated practical application, and capability of realizing 3.9[mu]m laser efficient output under a non-cooling room temperature condition.

The invention specifically relates to an intermediate infrared thulium-holmium co-doped sesquioxide laser single-crystal optical fiber, and a preparation method and application thereof, belonging to the technical field of laser materials. According to the intermediate infrared thulium-holmium co-doped sesquioxide laser single-crystal optical fiber provided by the invention, intermediate infrared laser in a waveband of 3.2-4.3 microns can be generated through transition between two excited state energy levels (5I5 to 5I6) of Ho<3+>; co-doping Tm<3+> has the synergistic effects of sensitizationand deactivation on the active ion Ho<3+>, can be used as both a sensitizing ion for the Ho<3+> and a deactivating ion for Ho<3+>, and allows the service life of the laser lower energy level 5I6 of Ho<3+> to be effectively shortened and the service life of the laser upper energy level 5I5 to be free of obvious changes, so a laser threshold value is favorably reduced, and the output efficiency andpower of laser are improved.

The invention provides a high-power slab green laser. The high-power slab green laser includes a pump source, a focusing system, a laser resonator and a self-frequency doubling crystal. The self-frequency doubling crystal is a neodymium ion doped calcium borate rare earth salt crystal cut into a slab shape along a direction of a maximum non-principal effective nonlinear coefficient of the crystal.Phase matching of different wavelengths is realized by changing a tangential direction of the crystal so as to realize laser output in 545 nm or 550 nm band. The pump source is a laser diode array having an emission center wavelength of 808 nm or 880 nm. An input cavity mirror and an output cavity mirror are coated with suitable film systems so as to obtain high-power laser output in the 545 nm or 550 nm band. The laser of the invention has the advantages of low laser threshold, high conversion efficiency and output power, and simple laser structure.

The invention belongs to the technical field of physical laser and relates to a tunable ultrashort pulse laser device with an eye-safe wave band; two endoscopes are respectively arranged on the same plane; a laser crystal, a group-velocity mismatch compensation device, a diaphragm and a phase mismatch compensation device are respectively arranged at intervals on the connecting line between the centers of the two endoscopes; a non-linear crystal and a trichroic endoscope are respectively arranged in inclination at the lower side of the centre line of the endoscopes arranged in an inclination structure; a diode laser device and a cooling device are arranged on the side of the laser crystal; the diode laser device is controlled by a driving power supply system; the laser crystal is pumped bythe diode laser device to combine the non-linear crystal and the trichroic endoscope; the tunable ultrashort pulse laser generated by mode-locked laser oscillation is realized by using the positive and negative directions of a light wave through the cascading second-order nonlinear effect of the non-linear crystal. The tunable ultrashort pulse laser device with the eye-safe wave band has the advantages of simple structure, small volume, low cost, low laser threshold value, low laser ion concentration and good prospect of application.

The invention relates to a transparent laser ceramic material, in particular to a preparation method of Nd:YVO4 transparent laser ceramic material, belonging to the technical field of an inorganic non-metallic material. The method comprises the following steps of: mixing the raw materials for preparing neodymium-doped yttrium vanadate laser material according to the proportion, grinding, sieving by 200 meshes after drying processing, pressing into bisque; carrying out vacuum sintering to the bisque with the vacuum degree of less than 10<-3>Pa, temperature-rising speed of 2 to 10 DEG C for every minute, sintering temperature of 1500 to 2000 DEG C and insulating time of 4 to 50 hours; and sintering ingot blanks, cooling with a furnace, annealing, carrying out planar processing after being taken out, and obtaining the transparent laser Nd:YVO4 ceramics after precisely polishing. The invention can improve the content of the rare soil element in the material, can prepare transparent ceramic with larger size, has shorter preparing period and lower cost, and better solves the problems that the doping concentration of single-crystal material is hard to be improved, the preparation with larger size is difficult and the like, thus leading the comprehensive performance of the material to be improved.

The invention relates to the field of laser, in particular to a method for realizing low pumping power density and a continuous optical pumping laser. The method takes convergent sunlight or light given out by continuous light sources as a pumping source, and adopts a thin or ultrathin laser gain medium to form a microchip laser or a rod-shaped laser. Optical materials which are doped with other ions are arranged on the circumference of the laser gain medium to absorb partial pumping light and give out upper transformed fluorescent light or lower transformed fluorescent light, and partial upper transformed fluorescent light or partial lower transformed fluorescent light is absorbed by the laser gain medium, so that the overall absorption efficiency is improved; and simultaneously a reflecting surface of a laser-cavity mirror is perpendicular to the surface of the thin gain medium, so that the power density of a laser cavity is strengthened and the laser start-oscillation threshold is reduced. The method can adopt a single microchip laser or a single rod-shaped laser, and can also adopt a plurality of groups of microchip lasers to be arranged on focus points of the pumping light.

The invention discloses a perovskite thin film packaging method for a water environment and application of the perovskite thin film packaging method, and belongs to the field of perovskite thin film packaging. The preparation method comprises the following steps: dripping an acrylic monomer on a glass slide, irradiating by using an ultraviolet LED lamp, and carrying out photopolymerization reaction on the monomer to generate a solid polymer layer 1; under a nitrogen protection condition, spin-coating a perovskite precursor solution on the solid polymer layer 1 to prepare a perovskite thin film; the perovskite thin film is filled and dispensed with an acrylic monomer, an ultraviolet LED lamp is used for irradiation, a polymerization reaction is carried out again, and a generated solid polymer layer 2 completely wraps the perovskite thin film in the middle. The influence of moisture and oxygen on the film is avoided, and the application range of the perovskite film is expanded. The packaged perovskite thin film can be directly used in a water area, and a lower laser threshold value and emission intensity are obtained.

The invention relates to a preparation method for an erbium-containing and neodymium-containing phosphorus germinate glass chip. The method comprises the following steps: a, mixing 40 to 70 molar percent of phosphorus pentoxide, 0 to 7.5 molar percent of germanium dioxide, 4 to 20 molar percent of zinc oxide, 0 to 50 molar percent of zinc chloride, 0.5 to 1 molar percent of erbium oxide and 2 to 5 molar percent of neodymium oxide uniformly; b, placing a mixture into a covered quartz crucible or platinum crucible, placing into an electric furnace and melting at the temperature of 1,300 and 1,450 DEG C to form molten glass; c, homogenizing and clarifying the molten glass which is molten completely, discharging out of the furnace and quickly pouring in a preheated die; d, putting the formed glass into a muffle furnace which is heated to the glass transition temperature and annealing; and e, taking out the glass sample after the glass sample is cooled completely. The prepared phosphorus germinate glass has the characteristics of high transparency, strong crystallization resistance, excellent heat stability and physicochemical properties, stable near infrared laser property and the like.