WO2020118914A1 - 一种高功率板条绿光激光器 - Google Patents

一种高功率板条绿光激光器 Download PDF

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Publication number
WO2020118914A1
WO2020118914A1 PCT/CN2019/076479 CN2019076479W WO2020118914A1 WO 2020118914 A1 WO2020118914 A1 WO 2020118914A1 CN 2019076479 W CN2019076479 W CN 2019076479W WO 2020118914 A1 WO2020118914 A1 WO 2020118914A1
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crystal
frequency
light
doubling
dielectric film
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PCT/CN2019/076479
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French (fr)
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张怀金
于浩海
杜金恒
王继扬
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山东大学
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/04—Arrangements for thermal management
    • H01S3/0405—Conductive cooling, e.g. by heat sinks or thermo-electric elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/02—Constructional details
    • H01S3/04—Arrangements for thermal management
    • H01S3/042—Arrangements for thermal management for solid state lasers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/094038—End pumping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
    • H01S3/105—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling the mutual position or the reflecting properties of the reflectors of the cavity, e.g. by controlling the cavity length
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
    • H01S3/106—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity
    • H01S3/108—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating by controlling devices placed within the cavity using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering
    • H01S3/109—Frequency multiplication, e.g. harmonic generation
    • H01S3/1095—Frequency multiplication, e.g. harmonic generation self doubling, e.g. lasing and frequency doubling by the same active medium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/1601—Solid materials characterised by an active (lasing) ion
    • H01S3/1603—Solid materials characterised by an active (lasing) ion rare earth
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/163—Solid materials characterised by a crystal matrix
    • H01S3/1666—Solid materials characterised by a crystal matrix borate, carbonate, arsenide

Definitions

  • the invention relates to a high-power slat green laser, which belongs to the technical field of lasers and nonlinear crystal devices.
  • Green light refers to light with a wavelength of 500 nm to 560 nm.
  • the green laser has been used in military and civilian fields such as laser display, instructions, and blinding weapons.
  • InGaN semiconductors the emission wavelength depends on the concentration of In.
  • the emission wavelength of commercial InGaN semiconductors is below 520 nm; while for Nd 3+ doped crystals such as commonly used yttrium vanadate and yttrium aluminum garnet, the emission peak is at 1064 nm Nearby, when doubling the frequency, a high-power, high-efficiency 532nm laser can be obtained.
  • the green light band practical lasers with wavelengths from 532nm to 560nm are still lacking, and this band is in the most sensitive area of the human eye (peak value is 555nm).
  • this band laser is also an important light source for blood detection, such as after carbon monoxide poisoning
  • the carboxyhemoglobin has an absorption peak at 545 nm. Therefore, practical lasers with wavelengths between 532nm and 560nm have important demands in the medical, military and other fields.
  • the currently reported practical light source for this band is only a 545nm self-doubling laser.
  • This method uses the focusing system to collimate and focus the pump light emitted from the pump source and then inject it into the self-doubling crystal through the input lens. Its maximum output The power is 3.01W.
  • This type of laser has the advantages of simple structure, stability, and compactness.
  • This mode has the advantages of good mode matching and high efficiency. It is suitable for watt-level low-power laser output, but the pump light of this structure is focused on the laser crystal and matched in mode Under the requirements of the pump, the pump spot is small (on the order of 100 microns), the heat generated during the laser is mainly concentrated in this area, and the direction of the temperature gradient is perpendicular to the direction of light propagation.
  • the slab laser can realize the amplification of the pump spot, and through the increase of the heat dissipation area, the heat can be effectively transmitted, but the traditional slab laser usually transmits its beam in the crystal in an M shape, and the laser self-doubling frequency requires strict Phase matching, that is to say, this traditional method is difficult to apply to the field of self-doubling laser to increase the output power. There are no reports on high-power slat green lasers in the field of self-doubling lasers.
  • the present invention provides a high-power slat green laser.
  • the invention is to cut into a lath crystal along the maximum direction of the effective nonlinear coefficient of the crystal, realize the laser oscillation of 1090nm or 1100nm band by coating, control the emission frequency, and realize the linear transmission of the laser in the crystal to ensure the phase matching; meanwhile, by changing From the cutting angle of the frequency-doubling crystal neodymium ion doped calcium borate rare earth salt crystal and the corresponding coating method, the effective output of the green light band to be achieved is selected, and the pump light spot uses a uniformly distributed rectangular spot, which is The crystal's thermal effect and heat dissipation method have been substantially changed, that is, the thermal distribution of the incident end surface only differs in the thickness direction of the crystal, that is, the thermal effect is one-dimensionally distributed, which effectively suppresses the thermal effect of the crystal, and the power can be greatly improved to obtain High power laser output.
  • the invention relates to two cavity mirrors and a self-doubling slab-shaped crystal.
  • the cost is low, the structure design is simple, and the end-face pumping mode is adopted, the working efficiency is high, the high-power, high-quality laser can be stably output, and the miniaturization is easy to realize.
  • High reflection refers to the reflectivity of light of a specific wavelength or band greater than 99%.
  • High transmittance refers to the transmittance of light with a specific wavelength or band greater than 99%.
  • Heat sink refers to the use of materials with high thermal conductivity (such as copper, silver, etc.) processed into a specific shape and wrapped on the crystal, at the same time, the internal processing of holes and a constant temperature cooling fluid to achieve the purpose of heat dissipation of the crystal, Or use external refrigeration equipment to keep the material temperature constant to achieve the purpose of heat dissipation of the crystal.
  • Slat-shaped crystal as shown in Figure 1, it means that the crystal light-transmitting surface is rectangular, and the width of the light-transmitting surface (W represents in the figure) is greater than the thickness (t represents in the figure).
  • the length of the crystal is the direction of the crystal In the figure, indicated by L, the upper and lower faces are the two large faces of the crystal, which are cooled by a heat sink.
  • Phase matching The physical essence of the so-called phase matching conditions is that the frequency-doubled light excited by the fundamental frequency light at various points along the crystal has the same phase when it propagates to the exit surface, so that it can interfere with each other and enhance, thus achieving a good frequency-doubling effect.
  • the fundamental frequency light can only get a good frequency doubling effect when it enters the crystal at a certain angle, while when it is incident at other angles, the frequency doubling effect is very poor, and even there is no frequency doubling light at all.
  • Mode matching It means that the size of the pump spot is close to the size of the fundamental mode oscillation spot of the laser resonator.
  • a high-power slatted green laser includes a pump source, a focusing system, and a laser resonant cavity arranged in sequence along the optical path.
  • a self-doubling frequency crystal is located between the input cavity mirror and the output cavity mirror in the resonant cavity;
  • the pump source is a pump light source of 790nm-890nm; using the end-face pumping method, the pump light spot is a uniformly distributed rectangular spot, which is focused on the self-doubling frequency crystal located in the resonant cavity by a focusing system;
  • Frequency-doubling crystals are neodymium ion-doped calcium oxyborate rare earth salt crystals cut into strips along the direction of the maximum effective nonlinear coefficient of the non-principal plane of the crystal;
  • the laser resonant cavity is composed of an input cavity mirror and an output cavity mirror; the input cavity mirror has a dielectric film A that is highly transparent to the pump light and highly reflective to the fundamental frequency light and the double frequency light; the output cavity mirror has a pair of pump light It is a dielectric film B that highly reflects the fundamental frequency light and transmits the frequency doubled light.
  • a preferred solution is that the input cavity mirror is coated with a medium that highly transmits the pump light at 790nm-890nm and highly reflects the fundamental frequency light at 1085nm-1095nm and the frequency doubled light at 540nm-547nm Film A1, the output cavity mirror has a dielectric film B1 that highly reflects the pump light 790nm-890nm band and the fundamental frequency light 1085nm-1095nm band and highly transmits the frequency doubled light 540nm-547nm band; and the crystal tangent is effective along 1090nm
  • the phase matching direction cutting with the largest nonlinear coefficient can achieve 545nm green laser output.
  • the input cavity mirror is plated with high transmission for the pump light 790nm-890nm band and high reflection for the fundamental frequency light 1095nm-1105nm band and frequency doubled light 547nm-555nm band Dielectric film A2
  • the output cavity mirror has a dielectric film B2 that highly reflects the pump light 790nm-890nm band and the fundamental frequency light 1095nm-1105nm band and highly transmits the frequency doubled light 547nm-555nm band; and the crystal tangent is along 1100nm
  • the phase matching direction cutting with the largest effective nonlinear coefficient can achieve 550nm green laser output.
  • the pump source is a laser diode array with an emission center wavelength of 808 nm or 880 nm.
  • the output wavelength of the pump source is stable and has a high output power.
  • the focusing system is one of the following components:
  • the combination of focusing systems is not limited to this, the purpose is to focus the spot into a rectangular spot.
  • the focal length of the focusing system is 1cm-30cm, depending on the application; the preferred focal length is 1-10cm.
  • the self-doubling frequency crystal is located at the focal point of the focusing system.
  • the light intensity density is larger and the light spot is smaller, which is conducive to the absorption of pump light by the frequency-doubling crystal.
  • the input cavity mirror is formed by coating the input mirror with a dielectric film A, or the light incident end surface of the frequency-doubling crystal is coated with a dielectric film A;
  • the output cavity mirror is formed by the output mirror with a dielectric film B It is formed, or is formed by plating a dielectric film B on the light exit end face of the frequency doubling crystal.
  • the dielectric film A and the dielectric film B are plated on the light passing surface of the self-doubling frequency crystal to form a cavity mirror, the dielectric film A and the dielectric film B constitute a laser resonant cavity.
  • the input cavity mirror and the output cavity mirror are coated with a dielectric film that highly reflects the fundamental frequency light, in order to realize the oscillation of the 1090nm or 1100nm band laser to generate the fundamental frequency light; the input cavity mirror is coated with a pair of 790nm-890nm
  • the dielectric film with high transmission band is coated with a dielectric film with high reflection on the 790nm-890nm band on the output cavity mirror to reduce the loss of pump light and increase the absorption of pump light by the self-doubling frequency crystal.
  • the neodymium ion-doped calcium borate rare earth salt crystal is one of neodymium-doped calcium gadolinium borate, neodymium-doped calcium oxylanthanum borate, neodymium-doped calcium yttrium borate, or neodymium Mixed crystals formed by two or three of doped calcium gadolinium borate, neodymium doped calcium lanthanum borate, and neodymium doped calcium yttrium borate; preferably neodymium ion-doped neodymium calcium borate rare earth salt crystal neodymium
  • the ion doping concentration is 1 at.% to 50 at.%, most preferably 6 at.% to 10 at.%.
  • the neodymium ion doped calcium borate rare earth salt crystals are commercially available or prepared according to the prior art.
  • the self-doubling frequency crystal has a rectangular light-transmitting surface, and the polished surface is plated with a dielectric film or a non-dielectric coating.
  • the crystal thickness is 0.4mm-2mm
  • the width of the self-doubling crystal is larger than the crystal thickness.
  • the length of the self-doubling crystal is 6mm-10mm
  • the crystal width is 12mm
  • the crystal thickness is 0.5-1mm. Changing the length of the crystal will not affect the laser output band, it will affect the efficiency of the laser. The efficiency is the best at the crystal length of 6mm-10mm, especially the self-doubling crystal length is 8mm.
  • heat sink cooling is adopted on the two large surfaces of the self-frequency-doubling crystal (that is, the two surfaces perpendicular to the light-transmitting surface). Conducive to laser heat dissipation.
  • the self-doubling frequency crystal transmission direction is the self-doubling frequency phase matching direction, that is, cutting along the direction of the maximum effective nonlinear coefficient of the non-principal plane of the crystal, and the optimal phase matching direction is: the maximum The angle between the Z axis of the main axis is (113° ⁇ 5°) and the angle between the X axis and the minimum crystal refractive index is (47° ⁇ 5°).
  • the phase matching of different wavelengths can be achieved by changing the tangential direction of the crystal.
  • green laser output in the 550 nm band can be achieved.
  • green laser output in the 545nm band can be achieved.
  • a preferred embodiment for realizing the 545 nm band laser is:
  • a high-power slat green laser includes a pump source arranged in sequence along the optical path, a focusing system, an input cavity mirror, a self-doubling frequency crystal, and an output cavity mirror; wherein the pump source has an emission center wavelength of 808 nm Or 880nm laser diode array; the self-doubling frequency crystal is a neodymium ion doped calcium borate rare earth salt crystal and is cut into a strip shape along the maximum direction of the effective nonlinear coefficient of 1090nm, the input cavity mirror is coated with a pair of 790nm-890nm Dielectric film A1 with high transmission band and high reflection to 1085nm-1095nm and 540nm-547nm band, output cavity mirror is coated with dielectric film B1 with high reflection to 1085nm-1095nm and 790nm-890nm band and high transmission to 540nm-547nm band
  • the self-doubling frequency crystal is located at the focal point of the focusing system and between the input cavity mirror and the output cavity
  • another preferred embodiment for realizing the 545 nm band laser is:
  • a high-power slat green laser includes a pump source arranged in sequence along the optical path, a focusing system, an input cavity mirror, a self-doubling frequency crystal, and an output cavity mirror; wherein the pump source has an emission center wavelength of 808 nm Or 880nm laser diode array; the self-doubling frequency crystal is a neodymium ion-doped calcium borate rare earth salt crystal and is cut into a strip shape along the maximum direction of the effective nonlinear coefficient of 1090nm, the self-doubling frequency crystal is located at the focus of the focusing system
  • the input cavity mirror is formed from the incident end face of the frequency-doubling crystal coated with a dielectric film A1 that is highly transparent to the 790nm-890nm band and highly reflective to the 1085nm-1095nm and 540nm-547nm bands; the output cavity mirror is a self-doubling crystal
  • the exit end surface is formed by coating a dielectric film B1 with high reflection in the 1085nm-1095nm
  • a preferred embodiment for realizing a 550 nm band laser is:
  • a high-power slat green laser includes a pump source arranged in sequence along the optical path, a focusing system, an input cavity mirror, a self-doubling frequency crystal, and an output cavity mirror; wherein the pump source has an emission center wavelength of 808 nm Or 880nm laser diode array; the self-doubling frequency crystal is a neodymium ion doped calcium borate rare earth salt crystal and is cut into a strip shape along the maximum direction of the effective nonlinear coefficient of 1100nm, the input cavity mirror is coated with a pair of 790nm-890nm Dielectric film A2 with high transmission band and high reflection to 1095nm-1105nm and 547nm-555nm band, output cavity mirror is coated with dielectric film B2 with high reflection to 1095nm-1105nm and 790nm-890nm band and high transmission to 547nm-555nm band
  • the self-doubling frequency crystal is located at the focal point of the focusing system and between the input cavity mirror and the output cavity
  • another preferred embodiment for realizing the 550 nm band laser is:
  • a high-power slat green laser includes a pump source arranged in sequence along the optical path, a focusing system, an input cavity mirror, a self-doubling frequency crystal, and an output cavity mirror; wherein the pump source has an emission center wavelength of 808 nm Or 880nm laser diode array; the self-doubling frequency crystal is a neodymium ion doped calcium borate rare earth salt crystal and is cut into a strip shape along the maximum direction of the effective nonlinear coefficient of 1100nm, the self-doubling frequency crystal is located at the focus of the focusing system
  • the input cavity mirror is formed from the incident end face of the frequency-doubling crystal coated with a dielectric film A2 that is highly transparent to the 790nm-890nm band and highly reflective to the 1095nm-1105nm and 547nm-555nm bands; the output cavity mirror is a self-doubling crystal
  • the exit end surface is formed by coating a dielectric film B2 with high reflection in the 1095nm-1105nm and 7
  • the invention is a high-power slat green laser, which is a special laser, which not only changes the shape of the crystal, that is, the crystal used is a slab crystal, but also uses a uniformly distributed rectangular spot for the pump light spot , Which makes the crystal's thermal effect and heat dissipation method substantially changed, that is, the heat distribution of the incident end surface only differs in the thickness direction of the crystal, that is, the thermal effect is one-dimensionally distributed, and the heat is dissipated through the two large surfaces of the crystal. , Greatly increasing the heat dissipation area of the crystal, which can effectively suppress the thermal effect of the crystal due to the increase in pump power, and the power can be greatly improved. The power has exceeded ten watts.
  • the solid laser of the present invention adopts a slat structure.
  • the pump spot is elongated, which can greatly increase the area of the pump spot.
  • the temperature gradient of the slat laser only occurs in the slat In the thickness direction, the two large surfaces of the crystal are cooled by a heat sink.
  • the thermal lens effect and thermal-optic distortion effect can be basically avoided. Therefore, the laser of the present invention can withstand greater pump power, and can achieve higher power green laser output.
  • the pump light emitted by the pump source of the present invention is collimated and focused into a uniformly distributed linear light spot by the focusing system in the direction of the fast axis, and then enters the self-frequency-doubling crystal through the input cavity mirror.
  • the self-frequency-doubling neodymium ion-doped calcium borate rare earth salt crystal light transmission direction is the self-frequency-doubling phase matching direction, that is, cutting along the direction of the maximum effective nonlinear coefficient of the non-principal plane of the crystal, the self-frequency-doubling crystal transmission surface is Rectangular, the width of the crystal is greater than the thickness of the crystal, the two large surfaces of the crystal are cooled by heat sinks, and the pump light is evenly distributed in the width direction of the crystal, so the thermal effect is one-dimensional (only in the direction perpendicular to the large surface of the crystal). Compared with the traditional rod-shaped laser crystal, the thermal effect is greatly reduced. Therefore, this laser can withstand greater pump power and output higher-power green laser light.
  • the self-frequency-doubling crystal of the present invention uses a slab-shaped neodymium ion-doped calcium borate rare earth salt crystal. Only one crystal can be used to achieve high-power stable output of green laser light, which fundamentally solves the all-solid-state
  • the stability problem of frequency-doubled green laser can achieve high power stable output of 545nm or 550nm green continuous laser.
  • breaking through the characteristics of the existing high-power green laser requires at least two (or even multiple) crystals. It has the advantages of simple structure, stability, compactness, and small size. It also reduces the difficulty of production debugging and processing, and is easy to install. , To ensure consistency in the production process, easy to mass production.
  • the high-power slat green laser of the present invention adopts neodymium ion doped calcium borate rare earth salt crystal which combines laser and frequency doubling effect, and the frequency is selected by changing the cutting angle and coating method to achieve 545nm or 550nm output.
  • Green laser In terms of output power, it breaks through the current situation that the all-solid-state self-doubling green laser is difficult to achieve high power output.
  • the green laser that can achieve high power stable output has exceeded ten watts, which is 3.01W green power.
  • the design of the resonant cavity mirror is simple, with a linear cavity, good stability and reliability, easy component replacement and debugging, and has the advantages of low laser threshold and easy implementation.
  • Figure 1 is a schematic diagram of a lath-shaped crystal.
  • the left side is the incident end face.
  • Pumping Laser represents the incident direction of the pump light
  • W represents the width of the crystal
  • t represents the thickness of the crystal
  • the two surfaces of W ⁇ t are the light-transmitting surfaces of the crystal.
  • the width W is greater than the thickness t
  • the crystal length L is the light transmission direction of the crystal
  • the right side is the exit end face
  • Output represents the exit direction of the laser.
  • FIG. 2 Schematic diagram of the 545nm high-power slab green laser in Example 1; where, 1 is the pump source; 2 is the focusing system; 3 is the dielectric film A; 4 is the self-doubling frequency crystal; 5 is the dielectric film B; 6 Is the laser output; 9 is the heat sink, and 10 is the indium foil.
  • FIG. 3 is a perspective view of FIG. 2.
  • FIG. 4 is a laser output spectrum of a 545 nm high-power slat green laser in Example 1, where the abscissa is the wavelength (nm) and the ordinate is the intensity.
  • FIG. 5 is another schematic structural diagram of a 545 nm high-power slat green laser in Example 10; where 7 is an input cavity mirror; 8 is an output cavity mirror.
  • 3-1 is a dielectric film with high transmission to 790nm-890nm
  • 3-2 is a dielectric film with high reflection to 1085nm-1095nm and 540nm-547nm.
  • 5-1 is a high reflection dielectric film for 790nm-890nm and 1085-1095nm
  • 5-2 is a high transmission dielectric film for 540-547nm.
  • FIG. 6 is a perspective view of FIG. 5.
  • Example 7 is a heat dissipation structure of a self-frequency-doubling crystal of a 545 nm high-power slab green laser in Example 1, where 9 is a heat sink and 10 is an indium foil.
  • Example 8 is a laser output spectrum of a 545 nm high-power lath green laser in Example 10, the abscissa is the wavelength (nm), and the ordinate is the intensity.
  • Example 9 is a laser output spectrum of a 550 nm high-power lath green laser in Example 19, the abscissa is the wavelength (nm), and the ordinate is the intensity.
  • Embodiment 1 High-power slat green laser that realizes 545nm green laser output
  • a high-power slatted green laser whose structure is shown in Figures 2 and 3, is composed of a pump source 1, a focusing system 2, and a self-frequency-doubling crystal 4 arranged sequentially along the optical path.
  • the pump source 1 is a laser diode array with an emission center wavelength of 808 nm;
  • the focusing system 2 is composed of a plano-convex cylindrical mirror with a focal length of 6.35 cm;
  • the self-frequency-doubling crystal 4 is neodymium ion doped calcium borate with a concentration of 8 at.% Gadolinium oxide crystal, the crystal length in the light transmission direction is 8mm, the light transmission surface is a rectangle of 12 ⁇ 1mm 2 and is polished.
  • the tangential direction is cut along the phase matching direction with the largest effective nonlinear coefficient of 1090nm.
  • the best phase matching direction is:
  • the main axis direction of the crystal refractive index (Z axis) is (113° ⁇ 1°), and the main axis direction of the crystal refractive index (X axis) is (49° ⁇ 2°).
  • the self-doubling crystal 4 is located at The focal point of the focusing system; the incident end surface of the self-doubling frequency crystal 4 is coated with a dielectric film A1 with high transmission to 790nm-890nm and high reflection to 1085nm-1095nm, 540nm-547nm, represented by 3 in Fig.
  • the exit end surface is plated
  • a high-power slat green laser as described in Example 1, except that the pump source 1 is a laser diode array with an emission center wavelength of 880 nm, and other conditions and components are the same as described in Example 1 and can be realized Green laser output at 545nm.
  • the quantum loss is small, which is beneficial to the efficient output of the laser.
  • a high-power slat green laser as described in Example 1, the difference is that the self-frequency-doubling crystal 4, the neodymium ion-doped calcium gadolinium borate crystal, the length of the light direction is 4mm, 6mm and 10mm, Other conditions and components are the same as described in Example 1. Both achieve 545nm band green laser output.
  • a high-power slat green laser as described in Example 1, except that the self-frequency-doubling crystal 4 and the transmission surface of neodymium ion-doped calcium gadolinium borate crystal are 12 ⁇ 0.5mm 2 , 6 respectively ⁇ 1 mm 2 , 8 ⁇ 1 mm 2 and 10 ⁇ 1 mm 2.
  • Other conditions and components are the same as described in Example 1. Both achieve 545nm band green laser output.
  • a high-power slatted green laser as shown in Figures 5 and 6, is composed of pump source 1, focusing system 2, input cavity mirror 7, self-doubling frequency crystal 4, and output cavity mirror 8 in order along the optical path. to make.
  • the pump source 1 is a laser diode array with an emission center wavelength of 808 nm; the focusing system 2 is composed of a plano-convex cylindrical mirror with a focal length of 6.35 cm; the input cavity mirror 7 and the output cavity mirror 8 form a laser resonant cavity.
  • the input cavity mirror 7 is a flat mirror, and the clear surface is coated with a dielectric film with a high transmission of 790nm-890nm (represented by 3-1 in FIG.
  • self-frequency-doubling crystal 4 is a neodymium ion doped concentration of 8at.% calcium gadolinium borate crystal, the direction of the crystal length is 8mm, the light side It is a rectangle of 12*1mm 2 and the light-transmitting surface is polished and coated with a dielectric film with high transmission to 790nm–890nm, 1060nm-1100nm and 532nm-550nm.
  • the tangential direction is cut along the phase matching direction with the largest effective nonlinear coefficient of 1090nm
  • the cutting angle is: (113° ⁇ 1°) with the Z axis and (49° ⁇ 2°) with the X axis.
  • the self-doubling frequency crystal 4 is located at the focal point of the focusing system; the output cavity mirror 8 is coated with a dielectric film with high reflection to 790nm-890nm, 1085nm-1095nm (represented by 5-1 in FIG. 5) and high to 540nm-547nm Through the dielectric film (indicated by 5-2 in FIG. 5), the two types of film systems together constitute the dielectric film B.
  • a high-power slat green laser is as described in Example 10, except that the pump source 1 is a laser diode array with an emission center wavelength of 880 nm, and other conditions and components are the same as those described in Example 10. Realize green laser output in 545nm band.
  • a high-power slat green laser as described in Example 10, the difference is that the self-frequency-doubling crystal 4, the neodymium ion-doped calcium gadolinium borate crystal in the light direction length are 4mm, 6mm and 10mm, Other conditions and components are the same as described in Example 10. Both achieve 545nm band green laser output.
  • a high-power slat green laser as described in Example 10, except that the self-frequency-doubling crystal 4 and the transmission surface of neodymium ion-doped calcium gadolinium borate crystal are 12 ⁇ 0.5mm 2 , 6 respectively ⁇ 1 mm 2 , 8 ⁇ 1 mm 2 and 10 ⁇ 1 mm 2 , other conditions and components are the same as described in Example 10. Both achieve 545nm band green laser output.
  • Embodiment 19 High-power slab laser to achieve 550nm green laser output
  • a high-power slat green laser as described in Example 1, the difference is: changing the cutting angle of the calcium-oxo-gadolinium borate crystal doped with neodymium ions from the frequency-doubling crystal, the crystal has the largest effective nonlinear coefficient along 1100nm
  • the phase matching direction is cut.
  • the best phase matching direction is: (113° ⁇ 1°) with the Z axis and (45° ⁇ 2°) with the X axis.
  • the dielectric film A2 with high transmission at 890nm and high reflection to 1095nm-1105nm, 547nm-555nm is represented by 3 in Figure 1; the exit end face is coated with high reflection to 790nm-890nm, 1095nm-1105nm and high transmission to 547nm-555nm
  • the dielectric film B2 is indicated by 5 in FIG. 3, and the dielectric film A2(3) and the dielectric film B2(5) constitute a laser resonator. Other conditions and components are the same as described in Example 1.
  • the output wavelength is 550nm, as shown in Figure 9.

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Abstract

本发明提供一种高功率板条绿光激光器，包括泵浦源，聚焦系统，激光谐振腔和自倍频晶体；所述自倍频晶体为沿晶体非主平面有效非线性系数最大方向切割成板条状的钕离子掺杂的硼酸钙氧稀土盐晶体；通过改变晶体的切向实现不同波长的相位匹配，实现545nn或550nm波段的激光输出；所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列；输入腔镜和输出腔镜镀有合适的膜系来获得545nm或550nm波段的大功率激光输出。本发明激光器具有低的激光阈值、高的转化效率和输出功率、激光器结构简单。

Description

一种高功率板条绿光激光器 技术领域
本发明涉及一种高功率板条绿光激光器，属于激光和非线性晶体器件技术领域。
背景技术
绿光指波长为500nm～560nm的光。绿光激光已经在激光显示、指示、致盲武器等军民两用领域获得实用。实用的绿光激光的产生方式主要有以下两种：基于铟(In)掺杂的GaN半导体(InGaN)发射以及Nd 3+掺杂激光晶体的倍频激光。其中对于InGaN半导体而言，其发射波长依赖In的浓度，目前商用InGaN半导体的发射波长为520nm以下；而Nd 3+掺杂晶体如常用的钒酸钇和钇铝石榴石，其发射峰值处于1064nm附近，对其倍频时，可获得高功率、高效率的532nm激光。纵观绿光波段，波长从532nm-560nm内实用化激光尚缺乏，而该波段处于人眼最敏感区域(峰值为555nm)，同时，该波段激光还是血液检测的重要光源，例如一氧化碳中毒后的碳氧血红蛋白在545nm存在吸收峰。因此，波长在532nm-560nm的实用激光在医疗、军事等领域有重要的需求。
目前报道的该波段实用光源仅为545nm自倍频激光器，该方式是以聚焦系统将泵浦源出射的泵浦光准直聚焦后通过输入透镜注入到所述自倍频晶体中，其最大输出功率为3.01W。该种激光器具有结构简单、稳定、紧凑等优势，该方式具有模式匹配好、效率高等优势，适合于瓦级小功率激光输出，但是该结构的泵浦光是聚焦于激光晶体中，在模式匹配的要求下，其泵浦光斑较小(百微米量级)，激光过程中产生的热量主要集中于该区域，且温度梯度的方向是与光传播方向垂直的，在热负荷条件下运转时，将产生严重的热透镜效应和光畸变效应，进而严重降低光束质量，甚至会发生晶体破裂，限制了激光输出功率的进一步提高。板条激光器可实现泵浦光斑的放大，并通过散热面积的加大，可实现热量的有效传输，但传统板条激光通常其光束以M形在晶体中传输，而激光自倍频需要严格的相位匹配，也就是说该传统方式难以适用于自倍频激光领域以提高输出功率。自倍频激光领域的高功率板条绿光激光器上未见报道。
发明内容
为了弥补现有技术的不足，本发明提供一种高功率板条绿光激光器。
发明概述：
本发明为沿晶体有效非线性系数最大方向切割成板条状晶体，通过镀膜实现1090nm或1100nm波段激光起振，控制发射频率，并实现激光在晶体中直线传输以保证相位匹配；同时，通过改变自倍频晶体钕离子掺杂硼酸钙氧稀土盐晶体的切割角度和相应的镀膜方式，选择要实现的绿光波段的有效输出，同时泵浦光光斑使用的是均匀分布的长方形光斑，这就使得晶体的热效应和散热方式得到了本质的改变，即入射端面的热分布只有在晶体厚度方向存在差异，也即热效应是一维分布的，有效抑制晶体的热效应，功率可以大幅度提升，从而获 得大功率激光输出。
本发明涉及两个腔镜和一个自倍频板条状晶体，成本低，结构设计简单，且采用端面泵浦方式，工作效率高，能稳定输出高功率、高质量激光，易于实现小型化。
术语说明：
高反射：是指对特定波长或波段光的反射率大于99％。
高透过：是指对特定波长或波段光的透过率大于99％。
热沉：是指使用热导率较高的材料(如铜、银等)加工成特定形状并包裹在晶体上，同时内部加工有孔道并通有恒温的冷却液以达到对晶体散热的目的，或者外部使用制冷设备使材料温度保持恒定从而达到对晶体散热的目的。
板条状晶体：如图1所示，是指晶体通光面为长方形，通光面宽度(图中W表示)大于厚度(图中t表示)的长方体，晶体长度即晶体的通光方向在图中用L表示，上下两个面即为晶体的两个大面，使用热沉冷却。
相位匹配：所谓相位匹配条件的物理实质就是使基频光在晶体中沿途各点激发的倍频光传播到出射面时，都具有相同的相位，这样可相互干涉增强，从而达到好的倍频效果。实验证明，基频光以某一特定角度入射晶体时，才能获得良好的倍频效果，而以其他角度入射时，则倍频效果很差，甚至完全不出倍频光。
模式匹配：是指泵浦光斑整形后尺寸与激光谐振腔基模振荡光斑尺寸接近。
本发明的技术方案如下：
一种高功率板条绿光激光器，包括沿光路依次排列的泵浦源、聚焦系统、激光谐振腔，有自倍频晶体位于谐振腔内输入腔镜和输出腔镜之间；其中，
所述泵浦源为790nm-890nm的泵浦光源；采用端面泵浦方式，泵浦光光斑是均匀分布的长方形光斑，通过聚焦系统聚焦于位于谐振腔内的自倍频晶体上；所述自倍频晶体是沿晶体非主平面有效非线性系数最大方向切割成板条状的钕离子掺杂硼酸钙氧稀土盐晶体；
所述激光谐振腔由输入腔镜和输出腔镜组成；输入腔镜有对泵浦光高透过且对基频光和倍频光高反射的介质膜A；输出腔镜有对泵浦光和基频光高反射且对倍频光高透过的介质膜B。
根据本发明，一种优选的方案是：所述输入腔镜镀有对泵浦光790nm-890nm波段高透过且对基频光1085nm-1095nm波段和倍频光540nm-547nm波段高反射的介质膜A1，输出腔镜有对泵浦光790nm-890nm波段和基频光1085nm-1095nm波段高反射且对倍频光540nm-547nm波段高透过的介质膜B1；且晶体切向是沿1090nm有效非线性系数最大的相位匹配方向切割，能实现545nm绿光激光输出。
根据本发明，另一种优选的方案是：所述输入腔镜镀有对泵浦光790nm-890nm波段高透过且对基频光1095nm-1105nm波段和倍频光547nm-555nm波段高反射的介质膜A2，输出腔镜有对泵浦光790nm-890nm波段和基频光1095nm-1105nm波段高反射且对倍频光547nm-555nm波段高透过的介质膜B2；且晶体切向是沿1100nm有效非线性系数最大的相 位匹配方向切割，能实现550nm绿光激光输出。
根据本发明优选的，所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列。该泵浦源出射波长稳定，并有着较高的输出功率。
根据本发明优选的，所述聚焦系统是下列组成之一种:
a.单个平凸柱面镜或多个平凸柱面镜组合，
b.单个平凸透镜或多个平凸透镜组合，
c.单个双凸透镜或多个双凸透镜组合，
d.平凸透镜与平凸、平凹柱面镜的组合，
e.双凸透镜与平凸、平凹柱面镜的组合。
聚焦系统的组合并不限于此，目的是为了把光斑聚焦成长方形光斑。聚焦系统的焦距1cm-30cm，根据使用情况而定；优选的焦距是1～10cm。
根据本发明优选的，所述自倍频晶体位于聚焦系统的焦点处。该处光强密度较大，光斑较小，有利于自倍频晶体对泵浦光的吸收。
根据本发明优选的，所述输入腔镜是输入镜镀以介质膜A形成，或自倍频晶体的光入射端面镀以介质膜A形成；所述输出腔镜是输出镜镀以介质膜B形成，或自倍频晶体的光出射端面镀以介质膜B形成。
根据本发明，将介质膜A、介质膜B镀于自倍频晶体通光面而形成腔镜的实施方案中，所述介质膜A和介质膜B构成激光谐振腔。
根据本发明，输入腔镜和输出腔镜上镀有对基频光高反射的介质膜，是为了实现1090nm或1100nm波段激光的振荡，产生基频光；输入腔镜上镀有对790nm-890nm波段高透过的介质膜，输出腔镜上镀有对790nm-890nm波段高反射的介质膜，是为了减小泵浦光的损耗、增加自倍频晶体对泵浦光的吸收。
根据本发明优选的，所述钕离子掺杂硼酸钙氧稀土盐晶体为钕掺杂硼酸钙氧钆、钕掺杂硼酸钙氧镧、钕掺杂硼酸钙氧钇中的一种，或者是钕掺杂硼酸钙氧钆、钕掺杂硼酸钙氧镧、钕掺杂硼酸钙氧钇中的2种或3种所形成的混晶；优选所述钕离子掺杂硼酸钙氧稀土盐晶体的钕离子掺杂浓度为1at.％～50at.％，最优选6at.％～10at.％。
根据本发明，所述钕离子掺杂硼酸钙氧稀土盐晶体可市购获得或按现有技术制备得到。
根据本发明优选的，所述自倍频晶体通光面为长方形，通光面抛光后镀以介质膜或不镀介质膜，自倍频晶体通光方向为晶体的长度方向，长度为0.5mm-50mm；晶体厚度为0.4mm-2mm，自倍频晶体宽度大于晶体厚度。进一步优选的，自倍频晶体长度为6mm-10mm，晶体宽度为12mm，晶体厚度为0.5-1mm。改变晶体的长度不会影响激光输出的波段，会对激光器效率有影响，在晶体长度6mm-10mm效率最好，特别是自倍频晶体长度为8mm效率最高。
根据本发明优选的，在所述自倍频晶体的两个大面(即垂直于通光面较大的两个面)采用热沉冷却。有利于激光器散热。
根据本发明优选的，所述自倍频晶体通光方向是自倍频的相位匹配方向，即沿晶体非主平面有效非线性系数最大方向切割，最佳相位匹配方向为：与晶体折射率最大的主轴方向Z轴夹角为(113°±5°)范围且与最小的晶体折射率主轴方向X轴夹角为(47°±5°)范围。
通过改变晶体的切向实现不同波长的相位匹配，当晶体切向是沿1100nm有效非线性系数最大的相位匹配方向切割，可实现550nm波段绿光激光输出。当晶体切向是沿1090nm有效非线性系数最大的相位匹配方向切割，可实现545nm波段绿光激光输出。
根据本发明，一个优选的实现545nm波段激光的实施方案是：
一种高功率板条绿光激光器，包括沿光路方向依次排列的泵浦源，聚焦系统，输入腔镜，自倍频晶体，输出腔镜；其中，所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列；所述自倍频晶体是钕离子掺杂硼酸钙氧稀土盐晶体且沿1090nm有效非线性系数最大方向切割成板条状，所述输入腔镜镀有对790nm-890nm波段高透过且对1085nm-1095nm和540nm-547nm波段高反射的介质膜A1，输出腔镜镀有对1085nm-1095nm和790nm-890nm波段高反射且对540nm-547nm波段高透过的介质膜B1；所述自倍频晶体位于聚焦系统的焦点处且位于输入腔镜和输出腔镜之间。
根据本发明，另一个优选的实现545nm波段激光的实施方案是：
一种高功率板条绿光激光器，包括沿光路方向依次排列的泵浦源，聚焦系统，输入腔镜，自倍频晶体，输出腔镜；其中，所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列；所述自倍频晶体是钕离子掺杂硼酸钙氧稀土盐晶体且沿1090nm有效非线性系数最大方向切割成板条状，所述自倍频晶体位于聚焦系统的焦点处；输入腔镜是自倍频晶体入射端面镀有对790nm-890nm波段高透过且对1085nm-1095nm和540nm-547nm波段高反射的介质膜A1而形成；输出腔镜是自倍频晶体的出射端面镀有对1085nm-1095nm和790nm-890nm波段高反射且对540nm-547nm波段高透过的介质膜B1而形成；所述介质膜A1和介质膜B1构成激光谐振腔。
根据本发明，一个优选的实现550nm波段激光的实施方案是：
一种高功率板条绿光激光器，包括沿光路方向依次排列的泵浦源，聚焦系统，输入腔镜，自倍频晶体，输出腔镜；其中，所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列；所述自倍频晶体是钕离子掺杂硼酸钙氧稀土盐晶体且沿1100nm有效非线性系数最大方向切割成板条状，所述输入腔镜镀有对790nm-890nm波段高透过且对1095nm-1105nm和547nm-555nm波段高反射的介质膜A2，输出腔镜镀有对1095nm-1105nm和790nm-890nm波段高反射且对547nm-555nm波段高透过的介质膜B2；所述自倍频晶体位于聚焦系统的焦点处且位于输入腔镜和输出腔镜之间。
根据本发明，另一个优选的实现550nm波段激光的实施方案是：
一种高功率板条绿光激光器，包括沿光路方向依次排列的泵浦源，聚焦系统，输入腔镜，自倍频晶体，输出腔镜；其中，所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列；所述自倍频晶体是钕离子掺杂硼酸钙氧稀土盐晶体且沿1100nm有效非线性系数最 大方向切割成板条状，所述自倍频晶体位于聚焦系统的焦点处；输入腔镜是自倍频晶体入射端面镀有对790nm-890nm波段高透过且对1095nm-1105nm和547nm-555nm波段高反射的介质膜A2而形成；输出腔镜是自倍频晶体的出射端面镀有对1095nm-1105nm和790nm-890nm波段高反射且对547nm-555nm波段高透过的介质膜B2而形成；所述介质膜A2和介质膜B2构成激光谐振腔。
本发明一种高功率板条绿光激光器，是一种特殊的激光器，其不仅改变的是晶体的形状即使用的晶体是板条状晶体，同时泵浦光光斑使用的是均匀分布的长方形光斑，这就使得晶体的热效应和散热方式得到了本质的改变，即入射端面的热分布只有在晶体厚度方向存在差异，也即热效应是一维分布的，再者就是通过晶体的两个大面散热，大大增大了晶体的散热面积，因而可以有效抑制晶体由于泵浦功率增加带来的热效应，功率可以大幅度提升。功率已经突破十瓦级。
本发明的技术特点及有益效果：
1、本发明采用板条结构的固体激光器通过使用板条形状的工作物质，泵浦光斑为长条状，可大大增加泵浦光斑的面积，同时，板条激光器的温度梯度只发生在板条厚度方向，晶体的两个大面采用热沉冷却，通过散热面积的增大和激光泵浦光斑的增大，可基本避免热透镜效应和热光畸变效应。因此，本发明的激光器可以承受更大的泵浦功率，可实现更高功率的绿光激光输出。
2、本发明泵浦源出射的泵浦光经过聚焦系统在快轴方向进行准直聚焦成均匀分布的线形光斑，再经过输入腔镜入射到自倍频晶体上。所述自倍频钕离子掺杂的硼酸钙氧稀土盐晶体通光方向是自倍频的相位匹配方向，即沿晶体非主平面有效非线性系数最大方向切割，自倍频晶体通光面为长方形，晶体宽度大于晶体厚度，晶体的两个大面采用热沉冷却，加之泵浦光在晶体宽度方向是均匀分布的，因此热效应是一维的(只在垂直于晶体大面方向)。与传统的棒状激光晶体相比，热效应大大减小，因此，这种激光器可以承受更大的泵浦功率，输出更高功率的绿光激光。
3、本发明自倍频晶体采用板条状的钕离子掺杂的硼酸钙氧稀土盐晶体，只需使用一块晶体就可以实现绿光激光的高功率稳定输出，从根本上解决了全固态自倍频绿光激光的稳定性问题，可以实现545nm或550nm绿光连续激光的高功率稳定输出。在结构上，突破现有大功率绿光激光器至少需要两块(甚至多块)晶体的特点，具有结构简单、稳定、紧凑、体积小等优势；还降低了生产调试和加工难度，易于装调，保证了生产过程中的一致性，易于批量化生产。
4、本发明的高功率板条绿光激光器是采用集激光和倍频效应于一身的钕离子掺杂硼酸钙氧稀土盐晶体，通过改变切割角度和镀膜方式进行频率选择实现545nm或550nm输出的绿光激光器。在输出功率上，突破现有全固态自倍频绿光激光器难以实现高功率输出的现状，可实现高功率稳定输出的绿光激光，功率已经突破十瓦级，比现有3.01W绿光功率显著提高；在激光过程上，谐振腔镜设计简单，呈直线腔，稳定性和可靠性好，便于元件更换和调 试，并具有激光阈值低、易于实现等优势。
附图说明
图1是板条状晶体示意图，左侧为入射端面，Pumping Laser代表泵浦光入射方向，W代表晶体的宽度，t代表晶体的厚度，W×t两个面即为晶体的通光面，其中宽度W大于厚度t，晶体长度L即为晶体的通光方向，右侧为出射端面，Output Laser代表激光的出射方向。
图2实施例1中545nm高功率板条绿光激光器结构示意图；其中，1是泵浦源；2是聚焦系统；3是介质膜A；4是自倍频晶体；5是介质膜B；6是激光输出；9是热沉，10是铟箔。
图3是图2的立体图。
图4是实施例1中545nm高功率板条绿光激光器的激光输出图谱，横坐标是波长(nm)，纵坐标是强度。
图5是实施例10中545nm高功率板条绿光激光器的另一种结构示意图；其中，7是输入腔镜；8是输出腔镜。3-1是对790nm-890nm高透过的介质膜，3-2是对1085nm-1095nm、540nm-547nm高反射的介质膜。5-1是对790nm-890nm和1085-1095nm高反射介质膜，5-2是对540-547nm高透过的介质膜。
图6是图5的立体图。
图7是实施例1中545nm高功率板条绿光激光器的自倍频晶体的散热结构，其中，9是热沉，10是铟箔。
图8是实施例10中545nm高功率板条绿光激光器的激光输出图谱，横坐标是波长(nm)，纵坐标是强度。
图9是实施例19中550nm高功率板条绿光激光器的激光输出图谱，横坐标是波长(nm)，纵坐标是强度。
具体实施方式
下面结合附图和实施例对本发明做进一步说明，但不限于此。
实施例中所用部件，如无特殊说明均为现有技术。
实施例1：实现545nm绿光激光器输出的高功率板条绿光激光器
一种高功率板条绿光激光器，结构如图2、3所示，由泵浦源1、聚焦系统2、自倍频晶体4沿光路顺序依次排列而成。泵浦源1是发射中心波长为808nm的激光二极管阵列；聚焦系统2是由焦距为6.35cm的平凸柱面镜组成；自倍频晶体4为钕离子掺杂浓度为8at.％的硼酸钙氧钆晶体，通光方向晶体长度是8mm，通光面为12×1mm 2的长方形，且抛光，切向是沿1090nm有效非线性系数最大的相位匹配方向切割，最佳相位匹配方向为：与晶体折射率最大的主轴方向(Z轴)为(113°±1°)、与最小的晶体折射率主轴方向(X轴)为(49°±2°)范围，所述自倍频晶体4位于聚焦系统的焦点处；在自倍频晶体4的入射端面镀有对790nm-890nm高透过且对1085nm-1095nm、540nm-547nm高反射的介质膜A1，由图1中3表示；出射端面镀有对790nm-890nm、1085nm-1095nm高反射且对540nm-547nm 高透过的介质膜B1，由图3中5表示，介质膜A1(3)和介质膜B1(5)构成激光谐振腔。
开启泵浦源1，加大泵浦功率，在49.7W泵浦功率下获得10W大功率的545nm波段绿光激光输出，输出波长如图4所示。
实施例2：
一种高功率板条绿光激光器，如实施例1所述，所不同的是泵浦源1是发射中心波长为880nm的激光二极管阵列，其它条件和部件与实施例1所述一致，可实现545nm波段绿光激光输出。使用本实施例中的激光器时，量子亏损少，有利于激光的高效输出。
实施例3-5：
一种高功率板条绿光激光器，如实施例1所述，所不同的是自倍频晶体4，钕离子掺杂的硼酸钙氧钆晶体的通光方向长度分别为4mm，6mm和10mm，其它条件和部件与实施例1所述一致。均实现545nm波段绿光激光输出。
实施例6-9：
一种高功率板条绿光激光器，如实施例1所述，所不同的是自倍频晶体4，钕离子掺杂的硼酸钙氧钆晶体的通光面分别为12×0.5mm 2，6×1mm 2，8×1mm 2和10×1mm 2，其它条件和部件与实施例1所述一致。均实现545nm波段绿光激光输出。
实施例10：
一种高功率板条绿光激光器，结构如图5、6所示，由泵浦源1、聚焦系统2、输入腔镜7、自倍频晶体4、输出腔镜8沿光路顺序依次排列而成。
泵浦源1是发射中心波长为808nm的激光二极管阵列；聚焦系统2是由一个焦距为6.35cm的平凸柱面镜组成；输入腔镜7和输出腔镜8构成激光谐振腔。输入腔镜7是平平镜，且通光面镀以对790nm-890nm高透过的介质膜(图5中3-1表示)且对1085nm-1095nm、540nm-547nm高反射的介质膜(图5中3-2表示)，两种膜系共同组成介质膜A1；自倍频晶体4为钕离子掺杂浓度为8at.％的硼酸钙氧钆晶体，通光方向晶体长度是8mm，通光面为12*1mm 2的长方形，且通光面抛光并镀有对790nm–890nm、1060nm-1100nm和532nm-550nm高透过的介质膜，切向是沿1090nm有效非线性系数最大的相位匹配方向切割，切割角度为：与Z轴成(113°±1°)、与X轴成(49°±2°)。并且所述自倍频晶体4位于聚焦系统的焦点处；输出腔镜8上镀有对790nm-890nm、1085nm-1095nm高反射的介质膜(图5中5-1表示)且对540nm-547nm高透过的介质膜(图5中5-2表示)，两种膜系共同组成介质膜B。
开启泵浦源1，加大泵浦功率，也获得545nm波段激光输出，输出波长如图8所示。
实施例11：
一种高功率板条绿光激光器，如实施例10所述，所不同的是泵浦源1是发射中心波长为880nm的激光二极管阵列，其它条件和部件与实施例10所述一致。实现545nm波段绿光激光输出。
实施例12-14：
一种高功率板条绿光激光器，如实施例10所述，所不同的是自倍频晶体4，钕离子掺杂的硼酸钙氧钆晶体的通光方向长度分别为4mm，6mm和10mm，其它条件和部件与实施例10所述一致。均实现545nm波段绿光激光输出。
实施例15-18：
一种高功率板条绿光激光器，如实施例10所述，所不同的是自倍频晶体4，钕离子掺杂的硼酸钙氧钆晶体的通光面分别为12×0.5mm 2，6×1mm 2、8×1mm 2和10×1mm 2，其它条件和部件与实施例10所述一致。均实现545nm波段绿光激光输出。
实施例19：实现550nm绿光激光器输出的高功率板条激光器
一种高功率板条绿光激光器，如实施例1所述，所不同的是：改变自倍频晶体钕离子掺杂的硼酸钙氧钆晶体的切割角度，晶体沿1100nm有效非线性系数最大的相位匹配方向切割，最佳相位匹配方向为：与Z轴成(113°±1°)、与X轴成(45°±2°)，在自倍频晶体4的入射端面镀有对790nm-890nm高透过且对1095nm-1105nm、547nm-555nm高反射的介质膜A2，由图1中3表示；出射端面镀有对790nm-890nm、1095nm-1105nm高反射且对547nm-555nm高透过的介质膜B2，由图3中5表示，介质膜A2(3)和介质膜B2(5)构成激光谐振腔。其他条件和部件与实施例1所述一致。
开启泵浦源1，加大泵浦功率，可实现550nm波段绿光激光输出。输出波长550nm，如图9所示。

Claims (10)

  1. 一种高功率板条绿光激光器，包括沿光路依次排列的泵浦源、聚焦系统、激光谐振腔，有自倍频晶体位于谐振腔内输入腔镜和输出腔镜之间；其中，
    所述泵浦源为790nm-890nm的泵浦光源；采用端面泵浦方式，泵浦光光斑是均匀分布的长方形光斑，通过聚焦系统聚焦于位于谐振腔内的自倍频晶体上；所述自倍频晶体是沿晶体非主平面有效非线性系数最大方向切割成板条状的钕离子掺杂硼酸钙氧稀土盐晶体；
    所述激光谐振腔由输入腔镜和输出腔镜组成；输入腔镜有对泵浦光高透过且对基频光和倍频光高反射的介质膜A；输出腔镜有对泵浦光和基频光高反射且对倍频光高透过的介质膜B。
  2. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列。
  3. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述自倍频晶体通光面为长方形，自倍频晶体通光方向为晶体的长度方向，长度为0.5mm-50mm；晶体厚度为0.4mm-2mm，且宽度大于晶体厚度；优选的，所述自倍频晶体长度为6mm-10mm，晶体宽度为12mm，晶体厚度为0.5-1mm；最优选自倍频晶体长度为8mm。
  4. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述聚焦系统是下列组成之一种:
    a.单个平凸柱面镜或多个平凸柱面镜组合，或，
    b.单个平凸透镜或多个平凸透镜组合，或，
    c.单个双凸透镜或多个双凸透镜组合，或，
    d.平凸透镜与平凸、平凹柱面镜的组合，或，
    e.双凸透镜与平凸、平凹柱面镜的组合；
    聚焦系统将光斑聚焦成长方形光斑。
    优选的聚焦系统的焦距1cm-30cm；进一步优选的焦距是1～10cm。
  5. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述输入腔镜是输入镜镀以介质膜A形成或自倍频晶体的光入射端面镀以介质膜A形成；所述输出腔镜是输出镜镀以介质膜B形成或自倍频晶体的光出射端面镀以介质膜B形成。
  6. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述钕离子掺杂硼酸钙氧稀土盐晶体为钕掺杂硼酸钙氧钆、钕掺杂硼酸钙氧镧、钕掺杂硼酸钙氧钇中的一种，或者是钕掺杂硼酸钙氧钆、钕掺杂硼酸钙氧镧、钕掺杂硼酸钙氧钇中的2种或3种所形成的混晶；优选所述钕离子掺杂硼酸钙氧稀土盐晶体的钕离子掺杂浓度为1at.％～50at.％，最优选钕离子掺杂浓度为6at.％～10at.％。
  7. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述自倍频晶体通光方向是自倍频的相位匹配方向，最佳相位匹配方向为：与晶体折射率最大的主轴方向Z轴夹 角为(113°±5°)范围且与最小的晶体折射率主轴方向X轴夹角为(47°±5°)范围。
  8. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，在所述自倍频晶体的两个大面采用热沉冷却。
  9. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述泵浦源为发射中心波长为808nm或880nm的激光二极管阵列；所述输入腔镜镀有对泵浦光高透过且对基频光和倍频光高反射的介质膜A，输出腔镜镀有对基频光和泵浦光高反射且对倍频光高透过的介质膜B；所述自倍频晶体位于聚焦系统的焦点处。
  10. 根据权利要求1所述的高功率板条绿光激光器，其特征在于，所述介质膜A、介质膜B为下列方案之一种：
    a.所述输入腔镜镀有对泵浦光790nm-890nm波段高透过且对基频光1085nm-1095nm波段和倍频光540nm-547nm波段高反射的介质膜A1，输出腔镜有对泵浦光790nm-890nm波段和基频光1085nm-1095nm波段高反射且对倍频光540nm-547nm波段高透过的介质膜B1；且晶体切向是沿1090nm有效非线性系数最大的相位匹配方向切割，能实现545nm绿光激光输出。
    b.所述输入腔镜镀有对泵浦光790nm-890nm波段高透过且对基频光1095nm-1105nm波段和倍频光547nm-555nm波段高反射的介质膜A2，输出腔镜有对泵浦光790nm-890nm波段和基频光1095nm-1105nm波段高反射且对倍频光547nm-555nm波段高透过的介质膜B2；且晶体切向是沿1100nm有效非线性系数最大的相位匹配方向切割，能实现550nm绿光激光输出。
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101950918A (zh) * 2010-09-03 2011-01-19 中国科学院理化技术研究所 一种适于激光显示用的自倍频绿光固体激光器
CN104184041A (zh) * 2014-09-12 2014-12-03 青岛科技大学 一种高功率中红外级联全固态激光器
CN109378698A (zh) * 2018-12-11 2019-02-22 山东大学 一种高功率板条绿光激光器

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CN102074888B (zh) * 2010-04-23 2012-03-07 中国科学院理化技术研究所 具有单一束激光输出或线阵激光输出的自倍频激光器
CN107453197A (zh) * 2017-07-26 2017-12-08 中国科学院理化技术研究所 一种用于激光显示的激光源

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101950918A (zh) * 2010-09-03 2011-01-19 中国科学院理化技术研究所 一种适于激光显示用的自倍频绿光固体激光器
CN104184041A (zh) * 2014-09-12 2014-12-03 青岛科技大学 一种高功率中红外级联全固态激光器
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