77results about How to "Increase laser output power" patented technology

The invention relates to a Bragg refractive waveguide edge transmitting semiconductor laser with a low horizontal divergence angle, wherein the P electrode of the laser is placed on the top face of a cover layer and is electrically connected onto the cover layer; the N electrode is positioned on the back face of a substrate and is electrically connected to the substrate; a center cavity is positioned between an upper waveguide layer and a lower waveguide layer; an active area is inserted in the center cavity; a Bragg refractive waveguide formed by periodically distributing a plurality of layers of N-doped materials with a high refractive index and a low refractive index is adopted in the lower waveguide layer on; and a Bragg refractive waveguide formed by periodically distributing a plurality of layers of P-doped materials with a high refractive index and a low refractive index is adopted in the upper waveguide layer. The Bragg refractive waveguide edge transmitting semiconductor laser with the low horizontal divergence angle has the advantages that: effects such as catastrophic damage, hole burning, electric heat overburning, beam filamentization and the like on the end face of the traditional edge transmitting semiconductor laser can be effectively improved, and the laser can realize the large mode-volume and stable single-transverse-mode work because of the great gain loss difference between a basic mode and a high-order mode, the full wave at half maximum (FWHM) of the transverse far-field divergence angle of the laser can reach below 10 DEG.

Optical pump modules comprising VCSEL and VCSEL array devices provide high optical power for configuring fiber optic gain systems such as fiber laser and fiber amplifier particularly suited for high power operation. Pump modules may be constructed using two reflector or three reflector VCSEL devices optionally integrated with microlens arrays and other optical components, to couple high power pump beams to a fiber output port. The pump module having a fiber output port is particularly suited to couple light to an inner cladding of a double-clad fiber, often used to configure high power fiber laser and fiber amplifier. The pump modules may be operated in CW, QCW and pulse modes to configure fiber lasers and amplifiers using single end, dual end, and regenerative optical pumping modes. Multiple-pumps may be combined to increase pump power in a modular fashion without significant distortion to signal, particularly for short pulse operation.

The invention relates to a tunable laser. Two laser gain mediums, one acousto-optic tunable filter and a single radio frequency transducer, one phase modulator and a signal control processing circuit based on micro processor are adopted; wherein the acousto-optic tunable filter comprises an acousto-optic crystal and an acoustic wave transducer which is welded on the surface selected by the crystal to generate acoustic wave, and different laser gain mediums, acoustic wave driving frequencies and acousto-optic crystals are utilized to manufacture various wideband tunable lasers for different applications. The invention has reasonable design, meets the requirements of submilisecond tuning speed, small size and high reliability under extreme condition in fiber optical communication, has the characteristics of fast tuning speed, low intracavity loss and high power output and realizes wide application of tunable laser with low cost, easy manufacturing and high performance in fiber optical communication network.

The invention discloses an optical fiber with a ring-shaped doped layer, which is used in an optical fiber laser and composed of an inner clad layer (101), a ring-shaped doped layer (102), a middle clad layer (103), an outer clad layer (104) and a protective layer (105), wherein the ring doped layer (102), the middle clad layer (103), the outer clad layer (104) and the protective layer (105) are, from inside to outside, sequentially clad on the inner clad layer (101), and the inner clad layer (101) is an undoped optical fire core. The invention also discloses a method for preparing the optical fiber with a ring-shaped doped layer, and a laser taking the optical fiber with a ring-shaped doped layer as a gain medium. According to the invention, the traditional fiber core doping is changed into a ring-shaped doped layer, so that the laser oscillation is actually performed in a ring-shaped waveguide, and then through reasonably designing the thickness of the ring-shaped waveguide, a single-mode operation can be kept; meanwhile, because the cross section area of the doped layer is large, the optical fiber with a ring-shaped doped layer is suitable to high-power output, therefore, the output power of the optical fiber laser using the optical fiber can be improved.

The present invention discloses an end pumped order variable gradient adulterate composite lath laser amplifier, which comprises a laser gain medium, seed source, pumping source, coupling lens duct, lath cooling heat sink and indium transition layer, characterized in that the laser gain medium is N-order order variable gradient adulterate composite ceramic lath and is composed by 2N+3 segments that is sub-lath in middle section that has highest luminous ion concentration decreases, each N segment sub-lath with luminous ion concentration decreases gradually towards two ends, and sub-lath with zero adulterate on two ends, wherein N is positive integer. The present invention can improve temperature distribution homogeneity and decrease biggest thermal stress, and further realize laser output of high average power and high beam quality.

External-cavity optically-pumped semiconductor lasers (OPS-lasers) including an OPS-structure having a mirror-structure surmounted by a surface-emitting, semiconductor multilayer (periodic) gain-structure are disclosed. The gain-structure is pumped by light from diode-lasers. The OPS-lasers can provide fundamental laser output-power of about two Watts (2.0 W) or greater. Intracavity frequency-converted arrangements of the OPS-lasers can provide harmonic laser output-power of about one-hundred milliwatts (100 mW) or greater, even at wavelengths in the ultraviolet region of the electromagnetic spectrum. These high output powers can be provided even in single axial-mode operation. Particular features of the OPS-lasers include a heat sink-assembly for cooling the OPS-structure, a folded resonator concept for providing optimum beam size at optically-nonlinear crystals used for frequency conversion, preferred selection of optically-nonlinear materials for frequency-conversion, and compound resonator designs for amplifying second harmonic-radiation for subsequent conversion to third or fourth harmonic radiation.

The invention discloses a gasifying and cutting method and instrument of tissue through high-power semiconductor pump laser, which is characterized by the following: utilizing high-order transverse-mould of high-power semiconductor pump Q-switch solid laser to output laser; reducing the irradiation to obtain little facular diameter on the soft tissue to increase laser power density; modifying the speed of gasifying cut tissue; improving outputting efficiency of laser; reducing power consumption; avoiding external water or secondary radiating laser system of circulated water.

The invention provides a portable-type laser cleaning head comprising a total reflector, an acousto-optic Q-switch, a semiconductor pumping module, an output mirror and a beam expander which are sequentially arranged on a main light path, wherein a scanning galvanometer is arranged in the output light direction of the beam expander, and a focusing lens is arranged on the reflecting light path of the scanning galvanometer. The laser output by the acousto-optic Q-switching solid laser device which is composed of the total reflector, the acousto-optic Q-switch, the semiconductor pumping module and the output mirror is expanded and shaped via the beam expander and then being incident on the scanning galvanometer; and the laser passing through the scanning galvanometer is focused on pollutants via the focusing lens to perform laser cleaning. According to the invention, the output power of laser is increased by means of acousto-optic Q-switching; and the main body of the laser device is placed in the laser cleaning head without a need of optical fibre transmission, so that the problems of low power, low monopulse energy, possibility of generating coupling loss during a transmission process, and easiness to damage transmission optical fibres of the present portable-type laser cleaner are solved.

The invention discloses airplane coated paint laser cleaning equipment which comprises a laser device 2 and a cleaning and processing head 3 connected with the laser device 2. A semiconductor pumping solid pulse laser device is adopted, and laser output power is improved by means of electro-optical modulation Q through an MOPA structure; optical fibers are coupled through a hollow cone, long-distance, large-range, long-time and stable cleaning is realized through optical fiber transmission, and no potential safety hazard is caused to an airplane body, so that cleaning cost is greatly lowered, pollution, of a paint stripper, to environment is reduced, and the airplane coated paint laser cleaning equipment can realize automatic control and is low in using cost and high in efficiency.

The invention relates to a single-mode photonic crystal edge-emitting semiconductor laser device. The single-mode photonic crystal edge-emitting semiconductor laser device comprises a laminated structure, wherein the laminated structure comprises a lower electrode, an N-type substrate, an N-type restriction layer, an active layer, a P-type restriction layer, a P-type cover layer, an SiO2 insulated layer and an upper electrode; the N-type substrate is manufactured on the lower electrode; the N-type restriction layer is manufactured on the N-type substrate; the active layer is manufactured on the N-type restriction layer; a three-section type waveguide raised along the longitudinal direction is arranged in the middle of the P-type restriction layer, opposite tapered waveguides are arranged on the two sides of the three-section type waveguide, and a photonic crystal waveguide is arranged between the opposite tapered waveguides and is manufactured on the active layer; the P-type cover layer is manufactured above the three-section type waveguide on the P-type restriction layer; the SiO2 insulated layer is manufactured on the side wall of the three-section type waveguide on the P-type restriction layer and covers upper part of the P-type restriction layer to form a substrate; the upper electrode is manufactured above the substrate except the side wall. Longitudinal mode and side mode of the laser device are selected through the photonic crystal waveguide, and the laser power is amplified by utilizing a symmetrical biconical structure, so that the purpose of high-power, single-mode and low-level divergence angle laser output is achieved.

The invention discloses a high energy hybrid thulium-doped pulse laser single-frequency amplifier which comprises a seed resource, a wavelength division multiplexer, an optical fiber pumping source, a polarization-maintaining single-mode single-cladding thulium-doped optical fiber, an isolator, a beam splitter, an output end, a filter, an acoustic optical modulator, a semiconductor pumping source and a laser crystal. The high energy hybrid thulium-doped pulse laser single-frequency amplifier has the advantages of being simple in structure and stable in system, the optical fiber-solid combined method is used, optical fiber amplification is adopted for a prime stage, the capacity for amplifying small signals is effectively improved, crystal amplification is adopted for a post stage, the advantage that solid lasers are prone to generating low-multi-pulse pulsed light is developed, the nonlinear effect easily occurring in optical fiber amplifying under high power is effectively avoided, low-multi-pulse high-energy pulse output is accordingly achieved, and the good application aspect is achieved.

The invention discloses a laser light source device and laser projection equipment. The laser light source device comprises at least three groups of laser arrays, a light combining reflector and a polarization light combining mirror, wherein the polarization light combining mirror and the light combining reflector are used for combining laser beams. The laser light source device is advantaged in that the scale of a single laser array does not need to be enlarged any more, light energy of the light source is improved in a mode that laser beams of the laser arrays are combined through multiple sets of laser array incident light combining reflectors and the polarization light combining mirrors, the combined laser beams are similar to the laser beams of a single laser array in size, and the power of the laser beams is remarkably improved, therefore, purposes of increasing the laser emitting power and keeping the small laser beam size are achieved, elements after a light path of the laser array does not need to be changed for redesign, and design cost is saved.

External-cavity optically-pumped semiconductor lasers (OPS-lasers) including an OPS-structure having a mirror-structure surmounted by a surface-emitting, semiconductor multilayer (periodic) gain-structure are disclosed. The gain-structure is pumped by light from diode-lasers. The OPS-lasers can provide fundamental laser output-power of about two Watts (2.0 W) or greater. Intracavity frequency-converted arrangements of the OPS-lasers can provide harmonic laser output-power of about one-hundred milliwatts (100 mW) or greater, even at wavelengths in the ultraviolet region of the electromagnetic spectrum. These high output powers can be provided even in single axial-mode operation. Particular features of the OPS-lasers include a heat sink-assembly for cooling the OPS-structure, a folded resonator concept for providing optimum beam size at optically-nonlinear crystals used for frequency conversion, preferred selection of optically-nonlinear materials for frequency-conversion, and compound resonator designs for amplifying second harmonic-radiation for subsequent conversion to third or fourth harmonic radiation.

The invention discloses a high combination property laser crystal and a preparation method thereof, which belongs to the technical field of solid laser. The high combination property laser crystal comprises a club-shaped laser crystal, cylindrical surfaces at two ends of the club-shaped laser crystal are provided with coatings of heat-sinking materials with high thermal conductivity, cylindrical surfaces of parts of the club-shaped laser crystal which is not coated are formed into threaded or uniformly distributed ring-shaped structures. The preparation method of the high combination property laser crystal includes manufacturing club-shaped laser crystals which meet processing requirements, and coating heat-sinking materials with high thermal conductivity on the parts which are not processed into threaded or ring-shaped structures at two ends of the club-shaped laser crystals. The invention overcomes turbulent movement in water cooling, resolves the cooling problem of the part which is not hydro-cooled, improves heat dissipation of the laser crystals, and raises pumping uniformity and laser beam quality. Experiments prove that under the same condition, the laser output power of the high combination property laser crystal increases approximately 15%, and heat performance raises over 20%, thereby realizing high density uniform pumping without damage.

The invention discloses an on-chip integrated cascade amplification semiconductor laser. The on-chip integrated cascade amplification semiconductor laser comprises a ridge type area, an on-chip DBR grating structure, a tapered type area and an epitaxial waveguide; the DBR grating structure is arranged on the ridge type area, the ridge type area is a ridge type waveguide structure, the tapered typearea is a gain waveguide structure; the epitaxial waveguide has a first-order ladder thickness; the ridge type area is arranged at a thin side of the epitaxial waveguide, the tapered type area is arranged at a thick side of the epitaxial waveguide, and the ridge type area and the tapered type area are cascaded. The laser of the design can more sufficiently utilize the tapered type area gain in comparison with a laser amplification way of traditionally utilizing the tapered gain structure; the base model feature is maintained when the mode volume is extended based on the iso-luminous flux principle, the optical quality of the near diffraction limit laser is guaranteed, and the brightness is greatly improved.

The invention discloses an all-optical-fibre mode-locked laser based on the Kerr effect of a multi-mode interference device; a pumping source emits an active optical fibre to absorb pump light in a band; after being coupled through a signal pumping beam combiner, the pump light enters the active optical fibre; the active optical fibre absorbs the pump light to form population inversion, so that laser gain is generated; the multi-mode interference device is formed by welding a section of multi-mode optical fibre in the middle of two sections of single-mode optical fibres; the transmission peak of the multi-mode optical fibre is the same to the gain peak of the active optical fibre; the signal pumping beam combiner, the active optical fibre, the multi-mode interference device, an output coupler and an isolator are in fusion welding in sequence, so that a one-way annular laser resonant cavity is formed; under the action of laser, the refractive index of the multi-mode optical fibre is changed; furthermore, the position of a multi-mode interference self-imaging point is changed; the transmittance of the multi-mode optical fibre at the position of laser wavelength is changed, so that the laser intensity of the annular laser resonant cavity is modulated; and the output coupler outputs ultra-short pulse laser. The all-optical-fibre mode-locked laser based on the Kerr effect of the multi-mode interference device disclosed by the invention is high in laser output power and low in cost.

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.

A MOPA laser system of four no coherent beams is composed of master oscillation unit formed by master oscillator, three beam splitters and one tail end total-reflection flat mirror; PCM power amplification unit including four single-channel power amplification units as each single-channel power amplification unit being formed by SBS phase conjugate mirror, biconvex lens, amplifier, rotator, polarization beam splitter and tail end total-reflection mirror; and reflection prism being used with two said units to form four beams of no coherent laser superposed beam.

The invention discloses a lath type carbon dioxide glass tube laser. The laser comprises a core discharge cavity. The core discharge cavity is sequentially coated with an inner glass tube and an outerglass tube, a positive discharge electrode and a negative discharge electrode are arranged at the two ends of the inner glass tube respectively, and an air return disc and a fixed disc are arranged at the positions, close to the positive discharge electrode and the negative discharge electrode, of the two ends of the inner glass tube respectively. Under the condition that the length is not increased, discharge volume is increased, working gas pressure is high, the obtained saturated light intensity is higher, that is, the laser gain is increased. The power output of the laser is approximatelyin direct proportion to the laser gain and in direct proportion to the saturation light intensity, so that higher laser output power can be obtained, the production cost of the laser tube is reduced,and under the condition of outputting the same laser power, the lath type carbon dioxide glass tube laser is shorter and has lower requirements on transportation and installation environments.

The invention relates to a Bragg refractive waveguide edge transmitting semiconductor laser with a low horizontal divergence angle, wherein the P electrode of the laser is placed on the top face of a cover layer and is electrically connected onto the cover layer; the N electrode is positioned on the back face of a substrate and is electrically connected to the substrate; a center cavity is positioned between an upper waveguide layer and a lower waveguide layer; an active area is inserted in the center cavity; a Bragg refractive waveguide formed by periodically distributing a plurality of layers of N-doped materials with a high refractive index and a low refractive index is adopted in the lower waveguide layer on; and a Bragg refractive waveguide formed by periodically distributing a plurality of layers of P-doped materials with a high refractive index and a low refractive index is adopted in the upper waveguide layer. The Bragg refractive waveguide edge transmitting semiconductor laser with the low horizontal divergence angle has the advantages that: effects such as catastrophic damage, hole burning, electric heat overburning, beam filamentization and the like on the end face of the traditional edge transmitting semiconductor laser can be effectively improved, and the laser can realize the large mode-volume and stable single-transverse-mode work because of the great gain loss difference between a basic mode and a high-order mode, the full wave at half maximum (FWHM) of the transverse far-field divergence angle of the laser can reach below 10 DEG.

The invention relates to an engineering ceramic material laser induction metamorphic wet-type grinding method. The engineering ceramic material laser induction metamorphic wet-type grinding method is characterized by including the following steps: (1) adopting Nd: radiating the surface of an engineering ceramic part through YAG lasers under the auxiliary-gas-free condition, and pre-inducing the surface of the engineering ceramic part to generate an initial metamorphic layer; (2) after the metamorphic layer is generated on the surface of the engineering ceramic part, carrying out accurate web-type grinding, wherein water-based cooling liquid is adopted, the liquid supplying pressure is 6 MPa, the grinding wheel linear speed is 60 m / s, the grinding depth is 1.5 mm, and the feeding speed is 2.0 m / min. By means of the engineering ceramic material laser induction metamorphic wet-type grinding method, the high-quality machined surface which is free of cracks, free of a fused metamorphic layer and low in roughness can be obtained, the machinability of ceramic materials can be greatly improved, and compared with engineering ceramic traditional grinding, machining by a large grinding depth is allowed. A new machining method is provided for hard, crisp and difficult-to-machine materials such as engineering ceramic.

By adopting the laser provided by the invention, when the same optical fiber laser is adopted, the higher light-to-light conversion efficiency than the existing 915nm, 940nm, 976nm and other conventional pumping modes can be realized, the quantum loss is smaller, and the SRS threshold value of the laser provided by the invention is higher than the SRS threshold value of the existing 1018nm pumpingmode. A TMI threshold value higher than that of an existing conventional pumping mode can be achieved. Through central wavelength optimization, a higher TMI threshold is obtained compared with a 976nm pumping mode, a higher SRS threshold is obtained compared with a 915 nm pumping mode, a 940 nm pumping mode and a 976 nm pumping mode, and the laser output power under the current pumping mode is greatly improved.

The invention provides a method for improving the performance of a DKDP crystal pockels cell. Apart from an annular main electrode, an annular auxiliary electrode is arranged at the two ends of an electro-optic crystal respectively so that each end of the crystal has a main electrode and an auxiliary electrode; the auxiliary electrode is arranged between the main electrode and the end surface of the electro-optic crystal; the auxiliary electrode and the main electrode are separated; voltage divider resistors are arranged between the auxiliary electrode and the main electrode at each end of the crystal as well as between two auxiliary electrodes; therefore, when a voltage V is applied between the main electrodes, an auxiliary voltage is applied between the main electrode and the auxiliary electrode through the voltage divider resistor; and the voltage generated by the auxiliary electrode compensates for the voltage unevenness of the end surface of the dual-electrode crystal by using the voltage characteristics of the annular electrode. The method of the invention can effectively improve the evenness of the radial extinction ratio of the electro-optical switch; and when the method is used in a Q switching pulse laser, the light leak of the electro-optical switch can be reduced, the output laser pulse width is compressed, the output ratio of Q-switching to free running is improved and the laser output power can be increased.

The invention provides a laser splitting method for preventing crystals from being damaged. The laser splitting method for preventing the crystals from being damaged includes the following steps: the nonlinear frequency conversion of first fundamental lasers and second fundamental lasers is carried out in the nonlinear optical crystals under the condition that phase matching is met and conversion lasers are generated. Before complete reflection occurs on the inner surface of the nonlinear optical crystals, the conversion lasers, the remaining first fundamental lasers and the remaining second fundamental lasers are mutually parallel or similarly parallel and transmitted in space in a mutual overlapping mode. After the complete reflection occurs on the inner surface of the nonlinear optical crystals, certain included angles exist mutually among the conversion lasers, the remaining first fundamental lasers and the remaining second fundamental lasers and the conversion lasers, the remaining first fundamental lasers and the remaining second fundamental lasers exit in the space in a mutual splitting mode. According to the laser splitting method for preventing the crystals from being damaged, the power density of exitance surfaces of the nonlinear optical crystals is decreased, the nonlinear optical crystals are protected from being damaged and meanwhile the output of pure frequency conversion lasers is obtained.

The invention relates to a laser system for four incoherent combined beams MOPA with high power. The laser system is composed of a main oscillation system, a PCM power amplifying system and a reflecting prism, wherein the main oscillation system comprises an oscillator 10, beam splitters 11, 12 and 13 and a main total reflection plane mirror 14; the PCM power amplifying system comprises four amplifying systems 2-1, 2-2, 2-3 and 2-4; each amplifying system is an optical system composed of an SBS phase-conjugation mirror, a convex lens, two amplifiers, a rotator, polarization beam splitters and auxiliary total reflection plane mirrors; optical axes are symmetrically distributed in the positions of the four edges of a rectangular prism; each auxiliary total reflection plane mirror respectively forms an included angle of 45 degrees with the optical axes; each beam splitter is respectively opposite and orthogonal to each polarization beam splitter; each auxiliary total reflection plane mirror is respectively arranged opposite and in parallel to corresponding edge plane total reflection mirrors 31, 32, 33 and 34; and four incoherent laser combined beams. The laser system has the advantages of high laser output power and good beam quality, and is applied in the military field, the industrial field and the like.

The invention discloses a single-lamp single-rod double-cavity light path system for a laser cutting machine. The light path system comprises a red lamp indicator, a total reflective mirror, light-gathering cavities, a semi-reflective mirror, a water-cooled beam-expanding mirror and a cutting head which are arranged in sequence. The light-gathering cavities comprise the first light-gathering cavity and the second light-gathering cavity. A first xenon lamp is arranged at one end of the first light-gathering cavity, and a first crystal rod is arranged at the other end of the first light-gathering cavity. A second xenon lamp is arranged at one end of the second light-gathering cavity, and a second crystal rod is arranged at the other end of the second light-gathering cavity. The cutting head comprises a head body, a 45-degree total reflective mirror, a focusing mirror, a protecting mirror and a nozzle, wherein the 45-degree total reflective mirror, the focusing mirror, the protecting mirror and the nozzle are connected to the head body in sequence. According to the single-lamp single-rod double-cavity light path system for the laser cutting machine, the mode of double light-gathering cavities is adopted, and the laser power can be increased by fifty percent when the same power is adopted by a laser power source, so that the output power of the equipment is increased, and the cutting capacity is improved.

The invention discloses an operating temperature self-adjusting system of a high repetition frequency industrial excimer laser. A temperature self-adjusting system which consists of a circulating water pump, a condenser, a temperature sensor, a temperature self-adjusting circuit, control software, a database which includes laser working states and parameters and the like is additionally arranged in an excimer laser system. The temperature self-adjusting system is used to control the operating temperature of the laser according to the laser operating parameters and states when the laser works, and accordingly, the inner temperature of a laser cavity body is controlled within the optimum energy scope so as to obtain the optimum output energy.

The invention discloses a rectangular laser generating device for a high-power dual-wavelength semi-conductor, which comprises an A stack (1), an A shaping lens (11), a B stack (2), a B shaping lens (21), a coupling mirror (3), a shaping lens (4), a reflection focusing mirror (5), an air inlet (6), an optical shutter (7), and a shielding box (8). According to the invention, the coupling mirror isadopted to stack two laser beams so as to improve the output power of the laser; the shielding box is used for insulating the internal environment and the external environment; the positive pressure air is input from the air inlet to prevent the external dust from invasion and the devices in the box is subjected to air cooling; the counter back pass of the external diffused photo thermal can be cut off by the action of the optical shutter diaphragm; the reflection focusing mirror is used for absorbing the photo thermal passing backing along the optical path in a counter manner, and the photo thermal is subjected to cooling; and through the coupling stacking, sealing isolating, diaphragm countersealing, reflection heat absorption and positive pressure air cooling, the output power of the semi-conductor laser generator is improved, so the purposes of dust encroachment separation, and back pass and per se photo-thermal damage prevention are achieved.

The invention belongs to the technical field of optical fiber manufacturing, and particularly discloses a preparation method of a taper-core optical fiber with a gradually-changed core-to-package ratio and the taper-core optical fiber. The method comprises the following steps: depositing a glass particle loose layer on the inner wall of a reaction tube; performing rare earth ion doping on the glass particle loose layer; drying the reaction tube, conducting sintering at high temperature, so as to vitrify the glass particle loose layer, conducting fusing to form a solid preform core rod, and then polishing the solid preform core rod to obtain a conical core rod with a specified taper angle; and conducting processing to obtain a cylindrical glass rod which is provided with a conical hollow hole, combining the glass rod with the conical hollow hole with a conical core rod to obtain a conical core active optical fiber preform, and putting the conical core active optical fiber preform into a wire drawing tower for drawing to obtain the conical core optical fiber with a gradually changed core-to-cladding ratio. The taper core optical fiber is prepared by the method. The core-to-package ratio of the prepared taper core optical fiber with the gradually-changed core-to-package ratio is gradually changed along with the length of the optical fiber, pump light absorption of the optical fiber can be improved, optical fiber heat production can be balanced, and laser output power can be improved.

The invention discloses an annealing method for improving laser output power of Nd3+:YAG crystal. The annealing method comprises the following steps of 1, putting an Nd3+:YAG crystal bar into a vacuum annealing furnace, and vacuumizing the vacuum annealing furnace to 0.08MPa by a vacuum pump; 2, opening an air inflation device, supplying a mixture gas of nitrogen and oxygen into the vacuum annealing furnace by a vacuum pipe, and maintaining the air pressure in the vacuum annealing furnace to 0MPa; 3, after the step 2 is finished, increasing the temperature in the vacuum annealing furnace to 1250-1300 DEG C; 4, maintaining the temperature in the vacuum annealing furnace to 1250-1300 DEG C; 5, after the step 4 is completed, lowering the temperature in the vacuum annealing furnace to 800 DEG C, and naturally cooling to the room temperature along with the furnace. Theannealing method has the advantages that by changing the annealing atmosphere, the constant temperature and the constant-temperature yearly hour are improved, so that the laser output power of the Nd3+:YAG crystal is greatly improved; compared with similar types of existing products, the laser output power is improved by 10-15%.