CN114518218A - Method and device for measuring loss in solid laser cavity - Google Patents
Method and device for measuring loss in solid laser cavity Download PDFInfo
- Publication number
- CN114518218A CN114518218A CN202210150755.4A CN202210150755A CN114518218A CN 114518218 A CN114518218 A CN 114518218A CN 202210150755 A CN202210150755 A CN 202210150755A CN 114518218 A CN114518218 A CN 114518218A
- Authority
- CN
- China
- Prior art keywords
- laser
- pump
- waist spot
- loss
- resonant cavity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 33
- 239000007787 solid Substances 0.000 title claims abstract description 21
- 239000013078 crystal Substances 0.000 claims abstract description 74
- 238000004364 calculation method Methods 0.000 claims abstract description 54
- 238000002347 injection Methods 0.000 claims abstract description 34
- 239000007924 injection Substances 0.000 claims abstract description 34
- 238000005086 pumping Methods 0.000 claims abstract description 30
- 230000003287 optical effect Effects 0.000 claims abstract description 14
- 239000011159 matrix material Substances 0.000 claims abstract description 11
- 238000010168 coupling process Methods 0.000 claims description 55
- 230000008878 coupling Effects 0.000 claims description 54
- 238000005859 coupling reaction Methods 0.000 claims description 54
- 238000010521 absorption reaction Methods 0.000 claims description 14
- 238000012360 testing method Methods 0.000 claims description 7
- 239000013307 optical fiber Substances 0.000 claims description 3
- PCTMTFRHKVHKIS-BMFZQQSSSA-N (1s,3r,4e,6e,8e,10e,12e,14e,16e,18s,19r,20r,21s,25r,27r,30r,31r,33s,35r,37s,38r)-3-[(2r,3s,4s,5s,6r)-4-amino-3,5-dihydroxy-6-methyloxan-2-yl]oxy-19,25,27,30,31,33,35,37-octahydroxy-18,20,21-trimethyl-23-oxo-22,39-dioxabicyclo[33.3.1]nonatriaconta-4,6,8,10 Chemical compound C1C=C2C[C@@H](OS(O)(=O)=O)CC[C@]2(C)[C@@H]2[C@@H]1[C@@H]1CC[C@H]([C@H](C)CCCC(C)C)[C@@]1(C)CC2.O[C@H]1[C@@H](N)[C@H](O)[C@@H](C)O[C@H]1O[C@H]1/C=C/C=C/C=C/C=C/C=C/C=C/C=C/[C@H](C)[C@@H](O)[C@@H](C)[C@H](C)OC(=O)C[C@H](O)C[C@H](O)CC[C@@H](O)[C@H](O)C[C@H](O)C[C@](O)(C[C@H](O)[C@H]2C(O)=O)O[C@H]2C1 PCTMTFRHKVHKIS-BMFZQQSSSA-N 0.000 abstract description 5
- 238000004458 analytical method Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 4
- 239000000835 fiber Substances 0.000 description 3
- 238000002834 transmittance Methods 0.000 description 3
- 239000004927 clay Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 1
- 229910017502 Nd:YVO4 Inorganic materials 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
- G01M11/02—Testing optical properties
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Lasers (AREA)
Abstract
The invention discloses a method and a device for measuring the intracavity loss of a solid laser, the method firstly draws an input-output power curve of the laser according to the injection pumping power and the corresponding laser output power of the laser, then reads a group of laser output powers corresponding to the injection pumping power at the position higher than the laser threshold value by combining the obtained input-output power curve through the measured laser threshold value of the laser, calculates and obtains the tilt efficiency of the laser, then calculates and obtains the size of a waist spot of a resonant cavity mode at a laser crystal by using an ABCD matrix at the position of the injection pumping power, and finally obtains the square value of the ratio of the tilt efficiency of the laser and the waist spot of the resonant cavity mode at the laser crystal to the waist spot of the pump laser by using calculation so as to realize the fast and accurate calculation and obtain the intracavity loss value of the laser And measuring the loss in the cavity of the multimode output fundamental frequency optical solid laser.
Description
Technical Field
The invention relates to the technical field of laser, in particular to a method and a device for measuring the intracavity loss of a solid laser.
Background
In the production, research and development and maintenance of a solid laser, the intracavity loss of the laser can limit the output power of the laser by influencing laser gain, the intracavity loss is used as an important index parameter for measuring the quality of the laser, and how to accurately measure the intracavity loss of the laser is helpful for guiding the optimal design of a laser resonant cavity, optimizing the output performance of the laser and prolonging the service life of the laser.
At present, a Findlay-Clay analysis method, a rate equation, a method based on laser power and relaxation oscillation frequency and a method for measuring linear loss in a cavity of an all-solid-state inner cavity frequency doubling laser are generally adopted for measuring the loss in the wall of the laser. The Findlay-Clay analysis method needs to replace a plurality of groups of output coupling transmissivity in operation, the operation inevitably changes the structure of a laser resonant cavity, errors are brought to measurement results, and meanwhile, the method has no effect on packaged lasers; the velocity equation adopts various approximations in the analysis process, and requires a comprehensive analysis on the energy level transition process of the low-gain laser medium, and the method is difficult to be suitable for measuring the loss in the high-gain laser cavity; the method for measuring the loss in the cavity based on the laser power and the relaxation oscillation frequency is applied under the scene of a single longitudinal mode stable running state, otherwise, when the laser has mode jump, although the laser power changes little, the relaxation oscillation frequency changes in a large range, large errors are brought to measurement results, and the method cannot be used for measuring the loss in the cavity of a single transverse mode laser with multiple oscillation frequencies and a multimode running laser; the method for measuring the linear loss in the cavity of the all-solid-state inner cavity frequency doubling laser by utilizing the nonlinear loss is characterized in that the fundamental wave and the second harmonic output power corresponding to two working temperature points of a frequency doubling crystal are measured in a single frequency region, and then substituted into a linear loss expression in the cavity of the laser to calculate the linear loss value in the cavity of the laser.
Disclosure of Invention
The invention aims to solve the technical problem that the conventional method for measuring the loss in the cavity of the laser cannot give consideration to the lasers in various modes, so that the invention provides the method and the device for measuring the loss in the cavity of the solid laser, and the method and the device are used for measuring the loss in the cavity of the fundamental frequency optical solid laser which is output in a single transverse mode, a single longitudinal mode and a multi-mode.
The invention is realized by the following technical scheme:
a method of measuring intracavity loss of a solid state laser, comprising:
acquiring injection pump power and corresponding laser output power of a laser to be detected, and drawing an input-output power curve based on the injection pump power and the laser output power;
reading the laser threshold of the laser to be detected, selecting a group of injection pumping power and laser output power at the position, higher than the laser threshold, of the input-output power curve, and calculating the laser skew efficiency;
acquiring a pump laser waist spot, and calculating a resonant cavity film spot at a laser crystal through a resonant cavity matrix at a position where pump power is injected; the pump laser waist spot refers to the size of the waist spot of the pump laser at the laser crystal;
and calling a laser intra-cavity loss calculation formula to calculate the laser tilt efficiency, the pump laser waist spot and the laser crystal resonant cavity mode waist spot to obtain an intra-cavity loss value of the laser.
Further, the acquiring of the injection pump power and the corresponding laser output power of the laser to be tested includes:
and injecting pump laser power into the laser to be tested, and calculating by a power meter in the laser to be tested based on the injected pump laser power to obtain corresponding laser output power.
Further, the reading a laser threshold of the laser to be tested, and selecting a set of injection pump power and laser output power at a position on the input-output power curve, which is higher than the laser threshold, to calculate the laser skew efficiency includes:
calling a laser skew efficiency calculation formula to calculate the selected injection pumping power, the output power and the laser threshold value to obtain laser skew efficiency;
the laser skew efficiency calculation formula specifically comprises:
in the formula etasDenotes the laser oblique efficiency, PoutIndicating the selected output power, PinIndicating the selected input power, PthIndicating the laser threshold.
Further, the calling a laser cavity internal loss calculation formula to calculate the laser oblique efficiency, the pump laser waist spot and the laser crystal resonant cavity mode waist spot to obtain the laser cavity internal loss value includes:
calculating a square value of the ratio of the resonant cavity mode waist spot at the laser crystal to the pump laser waist spot based on the pump laser waist spot and the resonant cavity mode waist spot at the laser crystal;
And calling a laser intra-cavity loss calculation formula to calculate the laser tilt efficiency and the square value of the ratio of the waist spots of the resonant cavity mode to the waist spots of the pump laser at the laser crystal to obtain the intra-cavity loss value of the laser.
Further, the calculation formula of the laser intra-cavity loss specifically includes:
where δ represents the laser intra-cavity loss; etaaShows the absorption efficiency, eta, of the gain medium to the pump lasera1-exp (- α l), wherein α represents the absorption coefficient of the gain medium to the pump laser in the laser to be tested, and l represents the radial length of the gain medium; etasRepresents the laser skew efficiency; v islIndicating the output laser frequency, vpThe frequency of the pump laser is represented, and T represents the transmissivity of an output coupling mirror in the laser to be tested; beta represents the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal,
wherein, ω islThe size, omega, of the waist spot of the resonant cavity mode at the laser crystalpIndicating the size of the pump laser waist spot.
Furthermore, the laser to be detected comprises a pump laser source, a coupling system, a power meter and a laser resonant cavity formed by an input coupling mirror, a first high reflection mirror, a second high reflection mirror and an output coupling mirror, wherein the laser resonant cavity is sequentially provided with a laser crystal and an optical isolator;
The laser is transmitted to the input coupling mirror after being coupled by the coupling system, the input coupling mirror transmits the received laser to the first high-reflection mirror through the laser crystal and the optical isolator, the first high-reflection mirror reflects the received laser to the second high-reflection mirror, the second high-reflection mirror transmits the received laser to the output coupling mirror, and the output coupling mirror transmits the received laser to the input coupling mirror; the power meter 9 is used to measure the output power when the output coupling mirror 6 outputs laser light.
Further, the pump laser source adopts a fiber coupled laser diode, the input coupling mirror adopts a concave lens, the first high-reflection mirror adopts a convex lens, and the second high-reflection mirror and the output coupling mirror are plano-concave lenses.
An apparatus for measuring solid state laser intracavity loss comprising:
the input-output power curve drawing module is used for acquiring the injection pumping power and the corresponding laser output power of the laser to be tested and drawing an input-output power curve based on the injection pumping power and the laser output power;
the laser skew efficiency calculation module is used for reading a laser threshold of the laser to be detected, selecting a group of injection pumping power and laser output power at a position on the input-output power curve, which is higher than the laser threshold, and calculating the laser skew efficiency;
The intracavity loss value calculation parameter acquisition module is used for acquiring a pumping laser waist spot and calculating a resonant cavity film light spot at the laser crystal through a resonant cavity matrix at the position where pumping power is injected; the pump laser waist spot refers to the size of the waist spot of the pump laser at the laser crystal;
and the intracavity loss value calculation module is used for calling a laser intracavity loss calculation formula to calculate the laser tilt efficiency, the pump laser waist spot and the laser crystal resonant cavity mode waist spot to obtain the intracavity loss value of the laser.
Further, the intra-cavity loss value calculation module includes:
the first calculation unit of the intracavity loss value is used for calculating a square value of the ratio of the waist spot of the resonant cavity mode at the laser crystal to the waist spot of the pump laser based on the waist spot of the pump laser and the waist spot of the resonant cavity mode at the laser crystal;
and the second calculation unit of the intra-cavity loss value is used for calling a calculation formula of the intra-cavity loss of the laser to calculate the laser tilt efficiency and the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal, so as to obtain the intra-cavity loss value of the laser.
Further, the calculation formula of the loss in the laser cavity is specifically as follows:
where δ represents the laser intra-cavity loss; eta aShows the absorption efficiency, eta, of the gain medium to the pump lasera1-exp (- α l), wherein α represents the absorption coefficient of the gain medium to the pump laser in the laser to be tested, and l represents the radial length of the gain medium; etasRepresents the laser skew efficiency; v. oflIndicating output laser frequency, vpThe frequency of the pump laser is represented, and T represents the transmissivity of an output coupling mirror in the laser to be tested; beta represents the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal,
wherein, ω islThe size, omega, of the waist spot of the resonant cavity mode at the laser crystalpIndicating the size of the pump laser waist spot.
The invention provides a method and a device for measuring the intracavity loss of a solid laser, firstly, an input-output power curve of the laser is drawn according to the injection pumping power of the laser and the corresponding laser output power, the measured laser threshold of the laser, in combination with the resulting input-output power curve, reading a group of laser output power corresponding to the injection pumping power at the position higher than the laser threshold value, calculating to obtain the tilt efficiency of the laser, then, at the position where the pump power is injected, the size of the waist spot of the resonant cavity mode at the laser crystal position is calculated by using an ABCD matrix, finally, the square value of the ratio of the laser oblique efficiency to the laser waist spot of the resonant cavity mode at the laser crystal position to the pump laser waist spot is obtained by calculation, so that the intracavity loss value of the laser can be quickly and accurately calculated, the method can give consideration to the measurement of the intracavity loss of the fundamental frequency light solid laser with single transverse mode, single longitudinal mode and multimode output.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
fig. 1 is a flow chart of a method for measuring the intracavity loss of a solid laser according to the present invention.
Fig. 2 is a flowchart illustrating step S40 of fig. 1 according to an embodiment of the present invention.
FIG. 3 is a schematic diagram of a laser under test according to an embodiment of the present invention.
FIG. 4 is a graph of input-output power curves in an embodiment of the present invention.
Fig. 5 is a schematic diagram of an apparatus for measuring the loss in a solid-state laser cavity according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
Example 1
As shown in fig. 1, the present invention provides a method for measuring the intracavity loss of a solid-state laser, including:
s10: obtaining the injection pumping power P of the laser to be testedinAnd corresponding laser output power PoutAnd based on the injected pump power P inAnd laser output power PoutAn input-output power curve is plotted.
In particular, by injecting a pump laser power P into the laser under testinCalculating to obtain corresponding laser output power P based on the power of the injected pump laser by a power meter in the laser to be measuredout。
As shown in fig. 3, the laser to be measured in this embodiment includes a pump laser source 1, a coupling system 2, a power meter 9, and a laser resonator formed by an input coupling mirror 3, a first high-reflection mirror 4, a second high-reflection mirror 5, and an output coupling mirror 6, and the laser resonator is sequentially provided with a laser crystal 7 and an optical isolator 8.
Specifically, the pump laser source 1 emits laser, and the laser is coupled by the coupling system 2 and then transmitted to the input coupling mirror 3, the input coupling mirror 3 transmits the received light to the first high-reflection mirror 4 through the laser crystal 7 and the optical isolator 8, the first high-reflection mirror 4 reflects the received light to the second high-reflection mirror 5, the second high-reflection mirror 5 transmits the received light to the output coupling mirror 6, and the output coupling mirror 6 transmits the received light to the input coupling mirror 3. The power meter 9 is used for measuring the laser output power when the output coupling mirror 6 outputs the laser, so as to facilitate the subsequent drawing of a laser input-output power curve.
Further, the pump laser source 1 adopts a fiber coupled laser diode, the input coupling mirror 3 adopts a concave lens, the first high-reflection mirror 4 adopts a convex lens, and the second high-reflection mirror 5 and the output coupling mirror 6 adopt a plano-concave lens.
S20: reading laser threshold value P of tested laserthAnd is higher than the laser threshold P on the input-output power curvethSelecting a group of injection pump power PinAnd laser output power, calculating the laser skew efficiency.
Specifically, a laser threshold of the laser to be detected is read, a group of injection pumping power and laser output power are selected at the position, higher than the laser threshold, of the input-output power curve, and a laser skew efficiency calculation formula is called to calculate the selected injection pumping power, the selected output power and the selected laser threshold, so that the laser skew efficiency is obtained.
The laser skew efficiency calculation formula specifically comprises:
in the formula etasDenotes the laser oblique efficiency, PoutIndicating the selected output power, PinIndicating the selected input power, PthIndicating the laser threshold.
S30: acquiring a pump laser waist spot, and calculating a resonant cavity film spot at a laser crystal through a resonant cavity matrix at a position where pump power is injected; wherein, the pump laser waist spot refers to the waist spot size of the pump laser at the laser crystal.
Specifically, a pump laser waist spot is obtained, and at the position of injecting pump power, a resonant cavity film spot at the laser crystal position is calculated through a resonant cavity ABCD matrix.
S40: and calling a laser intra-cavity loss calculation formula to calculate the laser tilt efficiency, the pump laser waist spot and the resonant cavity mode waist spot at the laser crystal to obtain an intra-cavity loss value of the laser.
Further, as shown in fig. 2, step S40, the method includes the following steps of calling a laser cavity internal loss calculation formula to calculate the laser skew efficiency, the pump laser waist spot, and the laser crystal resonant cavity mode waist spot, so as to obtain the laser cavity internal loss value:
s41: and calculating a square value of the ratio of the resonant cavity mode waist spot at the laser crystal to the pump laser waist spot based on the pump laser waist spot and the resonant cavity mode waist spot at the laser crystal.
S42: and calling a laser intra-cavity loss calculation formula to calculate the laser tilt efficiency and the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal to obtain the intra-cavity loss value of the laser.
Specifically, the calculation formula of the loss in the laser cavity is as follows:
where δ represents the laser intra-cavity loss. EtaaShows the absorption efficiency, eta, of the gain medium to the pump lasera1-exp (- α l), where α represents the absorption coefficient of the pump laser light by the gain medium in the laser under test, and l represents the radial length of the gain medium. EtasIndicating laser skew efficiency. V islIndicating the output laser frequency, vpRepresenting pump laser frequency, T representing output coupling mirror in laser under testTransmittance. Beta represents the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal, 
Wherein, ω islShowing the size of the waist spot of the resonant cavity mode at the laser crystal, omegapIndicating the size of the pump laser waist spot.
For ease of understanding, this is illustrated by way of example as follows:
the laser to be measured is an all-solid-state continuous 1064nm continuous wave laser with a four-mirror annular cavity structure, the input coupling mirror 3 adopts a concave lens with the curvature radius of 1500mm, and the concave lens is plated with a 888nm high-transmittance film with the light transmittance of more than 99.5 percent and a 1064nm high-reflectance film with the light reflectance of more than 99.7 percent; the first high-reflection mirror 4 adopts a convex lens with the curvature radius of 1500mm, and a 1064nm high-reflection film with the reflection rate of more than 99.7 percent is plated on the convex lens; the second high-reflection mirror 5 adopts a plano-concave lens with the curvature radius of-100 mm, and a 1064nm high-reflection film with the reflection rate of more than 99.7 percent is plated on the plano-concave lens; the output coupling mirror 6 adopts a plano-concave lens with the curvature radius of-100 mm, and the plano-concave lens is plated with a 1064nm light-transmitting film with the transmittance of 20%.
The pump source 1 adopts an 888nm optical fiber coupling laser diode, the diameter of a fiber core of the coupling optical fiber is 400 mu m, and the numerical aperture is 0.22; the waist spot of the laser emitted by the pump source 1 and focused at the center of the laser crystal 7 by the coupling system 2 is 0.570 mm; the laser crystal 7 is composed of a 3mm undoped end cap and 20mm composite YVO doped with Nd at 0.8 at% 4/Nd:YVO4(S1,S2:AR888nm；1064nm) The rear end of the laser crystal is cut at a small angle of 1.5 degrees to ensure the stable polarization of the laser.
In order to eliminate the spatial hole burning effect and achieve the unidirectional transmission of laser, an optical isolator 8 consisting of an 8mm long terbium gallium garnet TGG crystal and a half-wave plate is used in the laser resonant cavity. The optical path from the input coupling mirror 3 to the center of the laser crystal 7 is 10mm, the optical path from the center of the laser crystal 7 to the high reflecting mirror 4 is 120mm, the optical path from the high reflecting mirror 4 to the high reflecting mirror 5 is 128mm, the optical path between the high reflecting mirror 5 and the output coupling mirror 6 is 96mm, and the optical path from the output coupling mirror 6 to the input coupling mirror 3 is 125 mm.
When the pump power of the injected 808nm laser is 58W, the equivalent thermal lens focal length of the laser crystal is 137mm, and the resonant cavity mode omega of the laser crystal is obtained by calculation through the ABCD matrix in the resonant cavityl0.347 mm. According to a calculation formula of the absorption efficiency of the gain medium to the laser: etaaThe absorption efficiency of the laser crystal is calculated and obtained according to the wave bands of laser emitted by the pump laser source and output laser at the same time, wherein the wave bands are 1-exp (-alpha l), alpha is 1.07/cm and l is 20 mm:
the input-output power curve of the laser was constructed by ramping the injection pump power of the 888nm pump laser source and measuring the laser output power of the 1064nm output laser with a power meter 9, as shown in fig. 4. Reading the laser threshold P from FIG. 4 th32.33W, a set of injection pump powers P is selected above the laser thresholdin58W and corresponding laser output power Pout13.35W, according to the formula
Calculating to obtain the actual laser oblique efficiency of the laser
Measuring the actual parameter eta of the lasera＝1-exp(-107*0.02)，
The transmissivity T of the output coupling mirror of the laser is 20 percent, and the transmissivity T is substituted into a calculation formula of the loss in the laser cavity
The calculation in (1) gives the intracavity loss δ of the laser 5.28%.
It should be noted that the numerical values in the above embodiments are only examples, and are not used to limit the protection scope of the embodiments.
The invention provides a method for measuring the intracavity loss of a solid laser, which comprises the steps of firstly drawing an input-output power curve of the laser according to the injection pumping power of the laser and the corresponding laser output power, the measured laser threshold of the laser, in combination with the resulting input-output power curve, reading a group of laser output power corresponding to the injection pumping power at the position higher than the laser threshold value, calculating to obtain the tilt efficiency of the laser, then, at the position where the pump power is injected, the size of the waist spot of the resonant cavity mode at the laser crystal position is calculated by using an ABCD matrix, finally, the square value of the ratio of the laser oblique efficiency to the laser waist spot of the resonant cavity mode at the laser crystal position to the pump laser waist spot is obtained by calculation, so that the intracavity loss value of the laser can be quickly and accurately calculated, the method can give consideration to the measurement of the intracavity loss of the fundamental frequency light solid laser with single transverse mode, single longitudinal mode and multimode output.
Example 2
As shown in fig. 5, this embodiment provides a device for measuring the loss in the cavity of the solid state laser, which corresponds to the method for measuring the loss in the cavity of the solid state laser in embodiment 1 one to one, and includes an input-output power curve drawing module 10, a laser skew efficiency calculating module 20, an intra-cavity loss value calculating parameter obtaining module 30, and an intra-cavity loss value calculating module 40. The detailed description of each functional module is as follows:
and the input-output power curve drawing module 10 is used for the input-output power curve drawing module, and is used for acquiring the injection pumping power and the corresponding laser output power of the laser to be tested, and drawing an input-output power curve based on the injection pumping power and the laser output power.
And the laser skew efficiency calculating module 20 is configured to read a laser threshold of the laser to be detected, select a set of injection pump power and laser output power at a position on the input-output power curve that is higher than the laser threshold, and calculate the laser skew efficiency.
And the intra-cavity loss value calculation parameter acquisition module 30 is used for acquiring a pumping laser waist spot and calculating a resonant cavity film light spot at the laser crystal position through a resonant cavity matrix at the position where the pumping power is injected. Wherein, the pump laser waist spot refers to the waist spot size of the pump laser at the laser crystal.
And the intra-cavity loss value calculation module 40 is used for calling a laser intra-cavity loss calculation formula to calculate the laser oblique efficiency, the pump laser waist spot and the resonant cavity mode waist spot at the laser crystal to obtain the intra-cavity loss value of the laser.
Further, the intra-cavity loss value calculation module comprises a first intra-cavity loss value calculation unit and a second intra-cavity loss value calculation unit.
And the first calculation unit of the intra-cavity loss value is used for calculating a square value of the ratio of the waist spot of the resonant cavity mode at the laser crystal to the waist spot of the pump laser based on the waist spot of the pump laser and the waist spot of the resonant cavity mode at the laser crystal.
And the second calculation unit of the intra-cavity loss value is used for calling a calculation formula of the intra-cavity loss of the laser to calculate the oblique efficiency of the laser and the square value of the ratio of the waist spot of the resonant cavity mode at the laser crystal to the waist spot of the pump laser, so as to obtain the intra-cavity loss value of the laser.
Further, the calculation formula of the loss in the laser cavity is specifically as follows:
where δ represents the laser intra-cavity loss. EtaaShows the absorption efficiency, eta, of the gain medium to the pump lasera1-exp (- α l), where α represents the absorption coefficient of the gain medium for the pump laser light in the laser under test, and l represents the radial length of the gain medium. Eta sIndicating laser skew efficiency. v. oflIndicating the output laser frequency, vpRepresenting the pump laser frequency and T representing the transmissivity of the output coupling mirror in the laser under test. Beta represents the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal,
wherein, ω islThe size, omega, of the waist spot of the resonant cavity mode at the laser crystalpIndicating the size of the pump laser waist spot.
For the specific definition of a device for measuring the loss in the cavity of the solid-state laser, reference may be made to the above definition of a method for measuring the loss in the cavity of the solid-state laser, and details are not repeated here.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions.
The above embodiments are provided to further explain the objects, technical solutions and advantages of the present invention in detail, it should be understood that the above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. A method for measuring intracavity loss of a solid state laser, comprising:
acquiring injection pump power and corresponding laser output power of a laser to be detected, and drawing an input-output power curve based on the injection pump power and the laser output power;
reading the laser threshold of the laser to be detected, selecting a group of injection pumping power and laser output power at the position, higher than the laser threshold, of the input-output power curve, and calculating the laser skew efficiency;
obtaining a pumping laser waist spot, and calculating a resonant cavity film spot at a laser crystal through a resonant cavity matrix at a position where pumping power is injected; the pump laser waist spot refers to the size of the waist spot of the pump laser at the laser crystal;
and calling a laser intra-cavity loss calculation formula to calculate the laser tilt efficiency, the pump laser waist spot and the laser crystal resonant cavity mode waist spot to obtain an intra-cavity loss value of the laser.
2. The method according to claim 1, wherein the obtaining of the injection pump power and the corresponding laser output power of the laser under test comprises:
and injecting pump laser power into the laser to be tested, and calculating by a power meter in the laser to be tested based on the injected pump laser power to obtain corresponding laser output power.
3. The method according to claim 1, wherein the reading of the laser threshold of the laser under test and the selection of a set of injection pump power and laser output power on the input-output power curve above the laser threshold to calculate the laser tilt efficiency comprises:
calling a laser skew efficiency calculation formula to calculate the selected injection pumping power, the output power and the laser threshold value to obtain laser skew efficiency;
the laser skew efficiency calculation formula specifically comprises:
in the formula etasDenotes the laser oblique efficiency, PoutIndicating the selected output power, PinIndicating the selected input power, PthIndicating the laser threshold.
4. The method according to claim 1, wherein the step of calculating the laser tilt efficiency, the pump laser waist spot and the resonant cavity mode waist spot at the laser crystal by calling a laser cavity loss calculation formula to obtain the value of the laser cavity loss comprises:
calculating a square value of the ratio of the resonant cavity mode waist spot at the laser crystal to the pump laser waist spot based on the pump laser waist spot and the resonant cavity mode waist spot at the laser crystal;
And calling a laser intra-cavity loss calculation formula to calculate the laser tilt efficiency and the square value of the ratio of the waist spots of the resonant cavity mode to the waist spots of the pump laser at the laser crystal to obtain the intra-cavity loss value of the laser.
5. The method according to claim 4, wherein the calculation formula of the laser intracavity loss is specifically:
where δ represents the laser intra-cavity loss; etaaShowing the efficiency of absorption of the pump laser by the gain medium, ηa1-exp (- α l), wherein α represents the absorption coefficient of the gain medium to the pump laser in the laser to be tested, and l represents the radial length of the gain medium; etasRepresents the laser skew efficiency; v. oflIndicating output laser frequency, vpThe frequency of the pump laser is represented, and T represents the transmissivity of an output coupling mirror in the laser to be tested; beta represents the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal,
wherein, ω islThe size, omega, of the waist spot of the resonant cavity mode at the laser crystalpIndicating the size of the pump laser waist spot.
6. The method for measuring the intracavity loss of the solid laser as claimed in claim 1, wherein the laser to be measured comprises a pump laser source (1), a coupling system (2), a power meter (9), a laser resonant cavity formed by an input coupling mirror (3), a first high reflection mirror (4), a second high reflection mirror (5) and an output coupling mirror (6), and the laser resonant cavity is provided with a laser crystal (7) and an optical isolator (8) in sequence;
The laser coupling method comprises the steps that a pump laser source (1) emits laser, the laser is coupled by a coupling system (2) and then transmitted to an input coupling mirror (3), the input coupling mirror (3) transmits the received laser to a first high-reflection mirror (4) through a laser crystal (7) and an optical isolator (8), the first high-reflection mirror (4) reflects the received laser to a second high-reflection mirror (5), the second high-reflection mirror (5) transmits the received laser to an output coupling mirror (6), and the output coupling mirror (6) transmits the received laser to the input coupling mirror (3); the power meter 9 is used to measure the output power when the output coupling mirror 6 outputs laser light.
7. A method for measuring intracavity loss of a solid state laser as defined in claim 6,
the pump laser source (1) adopts an optical fiber coupling laser diode, the input coupling mirror (3) adopts a concave lens, the first high-reflection mirror (4) adopts a convex lens, and the second high-reflection mirror (5) and the output coupling mirror (6) adopt a plano-concave lens.
8. An apparatus for measuring the loss in a solid state laser cavity, comprising:
the input-output power curve drawing module is used for acquiring the injection pumping power and the corresponding laser output power of the laser to be tested and drawing an input-output power curve based on the injection pumping power and the laser output power;
The laser skew efficiency calculation module is used for reading a laser threshold of the laser to be detected, selecting a group of injection pumping power and laser output power at a position on the input-output power curve, which is higher than the laser threshold, and calculating the laser skew efficiency;
the intracavity loss value calculation parameter acquisition module is used for acquiring a pumping laser waist spot and calculating a resonant cavity film light spot at the laser crystal through a resonant cavity matrix at the position where pumping power is injected; the pump laser waist spot refers to the size of the waist spot of the pump laser at the laser crystal;
and the intracavity loss value calculation module is used for calling a laser intracavity loss calculation formula to calculate the laser tilt efficiency, the pump laser waist spot and the laser crystal resonant cavity mode waist spot to obtain the intracavity loss value of the laser.
9. The apparatus of claim 8, wherein the intra-cavity loss value calculation module comprises:
the first calculation unit of the intracavity loss value is used for calculating a square value of the ratio of the waist spot of the resonant cavity mode to the waist spot of the pump laser at the laser crystal based on the waist spot of the pump laser and the waist spot of the resonant cavity mode at the laser crystal;
and the second calculation unit of the intra-cavity loss value is used for calling a calculation formula of the intra-cavity loss of the laser to calculate the laser tilt efficiency and the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal, so as to obtain the intra-cavity loss value of the laser.
10. The apparatus of claim 9, wherein the calculation formula of the laser cavity loss is specifically:
where δ represents the laser intra-cavity loss; etaaShows the absorption efficiency, eta, of the gain medium to the pump lasera1-exp (- α l), wherein α represents the absorption coefficient of the gain medium to the pump laser in the laser to be tested, and l represents the radial length of the gain medium; etasRepresents the laser skew efficiency; v islIndicating the output laser frequency, vpThe frequency of the pump laser is represented, and T represents the transmissivity of an output coupling mirror in the laser to be tested; beta represents the square value of the ratio of the resonant cavity mode waist spot to the pump laser waist spot at the laser crystal,
wherein, ω islThe size, omega, of the waist spot of the resonant cavity mode at the laser crystalpIndicating the size of the pump laser waist spot.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210150755.4A CN114518218A (en) | 2022-02-18 | 2022-02-18 | Method and device for measuring loss in solid laser cavity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210150755.4A CN114518218A (en) | 2022-02-18 | 2022-02-18 | Method and device for measuring loss in solid laser cavity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114518218A true CN114518218A (en) | 2022-05-20 |
Family
ID=81598307
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210150755.4A Pending CN114518218A (en) | 2022-02-18 | 2022-02-18 | Method and device for measuring loss in solid laser cavity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114518218A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115290302A (en) * | 2022-10-10 | 2022-11-04 | 安徽华创鸿度光电科技有限公司 | Spontaneous radiation testing method and device of solid laser |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4793709A (en) * | 1985-08-16 | 1988-12-27 | Litton Systems, Inc. | Method and apparatus for measuring the losses of an optical cavity |
| GB0320315D0 (en) * | 2003-05-16 | 2003-10-01 | Metal Improvement Co | Self-seeded single-frequency solid-state ring laser, and single-frequency laser peening method and system using same |
| US6795190B1 (en) * | 2001-10-12 | 2004-09-21 | Los Gatos Research, Inc. | Absorption spectroscopy instrument with off-axis light insertion into cavity |
| CN101132100A (en) * | 2007-07-11 | 2008-02-27 | 南开大学 | Method for measuring intra-cavity loss of LD pumping solid state laser device and equipment using the method |
| CN101640370A (en) * | 2009-08-26 | 2010-02-03 | 福州高意通讯有限公司 | Demodulating method for realizing laser intracavity frequency doubling light and laser structure thereof |
| CN102175429A (en) * | 2011-01-11 | 2011-09-07 | 山西大学 | Method for measuring thermal focus length of laser |
| CN102243136A (en) * | 2011-04-14 | 2011-11-16 | 西安电子科技大学 | Laser gyro optical resonant cavity loss measurement system based on resonance method |
| CN102252825A (en) * | 2011-04-14 | 2011-11-23 | 西安电子科技大学 | System for measuring loss of optical resonant cavity based on optical cavity ring-down method |
| CN102620915A (en) * | 2012-04-01 | 2012-08-01 | 山西大学 | Measuring method for intra-cavity loss of all-solid-state laser |
| CN105973573A (en) * | 2016-05-25 | 2016-09-28 | 山西大学 | Measuring method for linear losses inside cavity of all-solid-state laser |
| CN106018285A (en) * | 2016-05-17 | 2016-10-12 | 山西大学 | Method for measuring absorption coefficient of nonlinear crystal |
| CN109586150A (en) * | 2018-11-29 | 2019-04-05 | 山西大学 | A kind of single resonance chamber realization continuous single frequency all-solid-state laser of hectowatt grade |
| US20210164850A1 (en) * | 2019-12-02 | 2021-06-03 | Shanxi University | Device and method for measuring thermal load caused by energy transfer upconversion in laser gain crystal |
-
2022
- 2022-02-18 CN CN202210150755.4A patent/CN114518218A/en active Pending
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4793709A (en) * | 1985-08-16 | 1988-12-27 | Litton Systems, Inc. | Method and apparatus for measuring the losses of an optical cavity |
| US6795190B1 (en) * | 2001-10-12 | 2004-09-21 | Los Gatos Research, Inc. | Absorption spectroscopy instrument with off-axis light insertion into cavity |
| GB0320315D0 (en) * | 2003-05-16 | 2003-10-01 | Metal Improvement Co | Self-seeded single-frequency solid-state ring laser, and single-frequency laser peening method and system using same |
| CN101132100A (en) * | 2007-07-11 | 2008-02-27 | 南开大学 | Method for measuring intra-cavity loss of LD pumping solid state laser device and equipment using the method |
| CN101640370A (en) * | 2009-08-26 | 2010-02-03 | 福州高意通讯有限公司 | Demodulating method for realizing laser intracavity frequency doubling light and laser structure thereof |
| CN102175429A (en) * | 2011-01-11 | 2011-09-07 | 山西大学 | Method for measuring thermal focus length of laser |
| CN102243136A (en) * | 2011-04-14 | 2011-11-16 | 西安电子科技大学 | Laser gyro optical resonant cavity loss measurement system based on resonance method |
| CN102252825A (en) * | 2011-04-14 | 2011-11-23 | 西安电子科技大学 | System for measuring loss of optical resonant cavity based on optical cavity ring-down method |
| CN102620915A (en) * | 2012-04-01 | 2012-08-01 | 山西大学 | Measuring method for intra-cavity loss of all-solid-state laser |
| CN106018285A (en) * | 2016-05-17 | 2016-10-12 | 山西大学 | Method for measuring absorption coefficient of nonlinear crystal |
| CN105973573A (en) * | 2016-05-25 | 2016-09-28 | 山西大学 | Measuring method for linear losses inside cavity of all-solid-state laser |
| CN109586150A (en) * | 2018-11-29 | 2019-04-05 | 山西大学 | A kind of single resonance chamber realization continuous single frequency all-solid-state laser of hectowatt grade |
| US20210164850A1 (en) * | 2019-12-02 | 2021-06-03 | Shanxi University | Device and method for measuring thermal load caused by energy transfer upconversion in laser gain crystal |
Non-Patent Citations (6)
| Title |
|---|
| GUO YR: "influence of the pump scheme on the output power and the intensity noise of a single-frequency continuous-wave laser", OPTICS EXPRESS, 17 February 2020 (2020-02-17) * |
| WANG H: "prior-damage dynamics in a high-finesse optical enhancement cavity", APPLIED OPTICS, 10 December 2020 (2020-12-10) * |
| 卢华东;: "利用弛豫振荡频率和输出功率测量单频钛宝石激光器的腔内损耗", 中国激光, no. 04, 10 April 2013 (2013-04-10) * |
| 毛丽琴, 王丽, 田宏宾: "新型全固态激光器作用过程中的激光参数分析", 光学技术, no. 06, 20 November 2005 (2005-11-20) * |
| 郭永瑞: "百瓦级低噪声全固态连续波单频激光器的研究", 中国博士学位论文全文数据库 基础科学辑, 25 December 2020 (2020-12-25) * |
| 闫甲楷: "薄膜—光腔耦合光力系统中的量子光学效应", 中国优秀硕士学位论文全文数据库 基础科学辑, 15 October 2018 (2018-10-15) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115290302A (en) * | 2022-10-10 | 2022-11-04 | 安徽华创鸿度光电科技有限公司 | Spontaneous radiation testing method and device of solid laser |
| CN115290302B (en) * | 2022-10-10 | 2023-01-03 | 安徽华创鸿度光电科技有限公司 | Spontaneous radiation testing method and device of solid laser |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1741328B (en) | Diode-pumped laser | |
| CN112345209B (en) | End-pumped laser crystal thermal focus measuring device and method | |
| CN105973573B (en) | The measuring method of all solid state laser intracavitary linear impairments | |
| CN110895239B (en) | Device and method for measuring excited state absorption heat load in laser gain crystal | |
| CN102637995A (en) | Dual-wavelength or multi-wavelength laser with adjustable power proportion | |
| CN114518218A (en) | Method and device for measuring loss in solid laser cavity | |
| CN110323663B (en) | Device and method for generating vector ultrashort laser pulse of intermediate infrared band | |
| CN109586150B (en) | Hectowatt-level continuous single-frequency all-solid-state laser realized by single resonant cavity | |
| CN114509242B (en) | Method and device for measuring focal length of laser crystal thermal lens | |
| US11916349B2 (en) | Device and method for measuring thermal load caused by energy transfer upconversion in laser gain crystal | |
| CN219532452U (en) | Laser crystal thermal lens focal length measuring device | |
| CN113572001A (en) | Single-ended pumping Q-switched laser based on doping concentration gradient crystal | |
| US20090316732A1 (en) | Fiber optic power laser device | |
| CN108512027B (en) | Annular cavity amplifying device for picosecond seed laser pulse | |
| CN216529826U (en) | Resonant cavity of all-solid-state laser and all-solid-state laser | |
| JP3074692B2 (en) | Edge-pumped solid-state laser oscillator | |
| CN111585159B (en) | Device and method for guaranteeing frequency stability of microchip laser | |
| CN108039638B (en) | Low-threshold two-stage spectrum shaping flexible optical fiber high-power mode-locked laser | |
| CN114526893B (en) | Method and device for measuring stimulated emission section of laser crystal | |
| CN101494355A (en) | Dual-cavity laser | |
| CN212721990U (en) | Laser crystal thermal focus measuring device | |
| CN116539279B (en) | Measuring system and measuring method for absorption coefficient of cladding pumping light | |
| CN114050469B (en) | Integrated device for optical fiber laser and manufacturing and testing method thereof | |
| CN218123957U (en) | Cascade multi-wavelength tunable laser for laser radar light source | |
| CN116698362A (en) | Method and device for measuring focal length of end-pumped laser crystal thermal lens |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |