CN102244341A - Device and method for improving linear polarization output power of neodymium:yttrium aluminum garnet (Nd:YAG) laser - Google Patents
Device and method for improving linear polarization output power of neodymium:yttrium aluminum garnet (Nd:YAG) laser Download PDFInfo
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- CN102244341A CN102244341A CN 201110147802 CN201110147802A CN102244341A CN 102244341 A CN102244341 A CN 102244341A CN 201110147802 CN201110147802 CN 201110147802 CN 201110147802 A CN201110147802 A CN 201110147802A CN 102244341 A CN102244341 A CN 102244341A
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Abstract
The invention relates to a device and a method for improving the linear polarization output power of a rod-like neodymium:yttrium aluminum garnet (Nd:YAG) laser. In the method, compared with a conventional Nd:YAG crystal rod cut in a direction [111], the Nd:YAG crystal rod cut in the direction [100] by a lateral pump of a semiconductor laser improves the output energy of linearly polarized light in fit with a proper linear polarization direction. The method provided by the invention can be widely used for the all-solid state rod-like Nd:YAG laser; and the all-solid state rod-like Nd:YAG laser can be ensured to have the characteristics of high linearly polarized light power, low thermally induced depolarization loss, operational simplicity and the like, and is easy to apply to engineering.
Description
Technical field
The present invention relates to the Nd:YAG crystal bar of a kind of use semiconductor laser side face pumping [100] direction cutting, and rotate the device and method that the polarisation optical splitter is sought maximum linearly polarized light power output, belong to laser and make the field.
Background technology
The absorption spectrum matching degree height of the emission spectrum of semiconductor laser and solid state gain medium, still along with the increase of draw power, the thermal effect of laser medium is more and more obvious, causes phenomenons such as thermally induced birefringence.Need the laser of linearly polarized light beam for running, such as electric-optically Q-switched, frequency multiplication and light beam external modulation etc., the hot fevering sodium effect that is caused by thermally induced birefringence will obviously increase, and has a strong impact on the power output of solid state laser.In order to reduce of the influence of hot fevering sodium effect to laser performance, mainly take to compensate at present the way of thermally induced birefringence, what make every bit on the excellent cross section radially all obtains identical phase delay with the tangential polarization radiation.Common compensation method is the hot depolarization that integrated Faraday rotator and speculum come compensated oscillator.
W.Koechner has carried out theory analysis with D.K.Rice in the thermally induced birefringence at the Nd:YAG crystal bar of different cut direction in 1970, has calculated under the different polarization direction Changing Pattern of single-pass running thermally induced birefringence.Oliver Puncken, Henrik T ü nnermann, James J.Morehead equal to carry out in 2010 the experiment of detection light on the basis of theory analysis, drawn similar conclusion.Content of the present invention is to use the Nd:YAG crystal bar of [100] direction cutting as laser medium, carries out the free oscillation experiment, and research is to the value of actual laser.By changing the polarization direction of linearly polarized light, can obtain maximum linearly polarized light power output, obvious improvement has been arranged than the Nd:YAG crystal bar of [111] direction cutting during as laser medium, promptly can effectively improve the linearly polarized light power output of bar-shaped Nd:YAG laser under the free oscillation condition.
Summary of the invention
The objective of the invention is to overcome the deficiency of the Nd:YAG crystal thermal depolarization compensation method of common [111] direction cutting, propose a kind of device and method that improves bar-shaped Nd:YAG crystal laser linearly polarized light power output.
Completely reflecting mirror (1), laser medium (4) and outgoing mirror (5) order are placed and are constituted laserresonator, and laser medium (4) is installed in the semiconductor laser module (3), and semiconductor laser module (3) profile pump laser medium (4) produces laser.Laser medium (4) is to use the Nd:YAG crystal bar of [100] cut direction, is provided with the polarisation optical splitter (2) of the linearly polarized laser that can make laser output P polarisation between laser medium (4) and the completely reflecting mirror (1).In adjustment process, the polarisation optical splitter (2) that is provided with between rotary laser medium (4) and the completely reflecting mirror (1), in the rotation adjustable range of 360 degree, there is the period of change of four linearly polarized light power outputs, four linearly polarized light power output maximum and minimum are arranged respectively.The hot depolarization of laser is the key factor that influences linearly polarized light power output size, and hot depolarization is more little, and the linearly polarized light power output is big more.Choose the direction of the direction of any one linearly polarized light power output maximum wherein as the polarisation optical splitter, under laser free oscillation condition, can make the hot depolarization minimum of laser, realize the raising of bar-shaped Nd:YAG crystal laser linearly polarized light power output.
The present invention has realized the raising of bar-shaped Nd:YAG crystal laser linearly polarized light power output with brand-new thinking, and the method that compensates hot depolarization than tradition has following advantage:
Hot fevering sodium effect obviously reduces;
Avoided inserting the excess loss that device brought of the hot depolarization of compensation;
Laser output power can improve more than 10% than the method for the hot depolarization of tradition compensation;
Greatly reduce the laser cost;
Operate more simply, be easy to realize that engineering uses.
The present invention has substantial characteristics and marked improvement, and method of the present invention can be widely used in can obviously improving efficient, stability and the power output of laser in the semiconductor pumped bar-shaped Nd:YAG crystal laser.
Description of drawings
Fig. 1 is a system schematic of the present invention
Fig. 2 is a polarisation optical splitter work schematic diagram
Fig. 3 be perpendicular in [111] the direction Nd:YAG rod cross section θ angle and
The graph of a relation at angle
Fig. 4 be perpendicular in [100] the direction Nd:YAG rod cross section θ angle and
The graph of a relation at angle
Fig. 5 is (45 degree) in the linearly polarized light variable power cycle, when pumping [111] direction cutting Nd:YAG crystal cuts the Nd:YAG crystal with [100] direction, and power output Changing Pattern graph of a relation
When Fig. 6 is pumping [100] direction cutting Nd:YAG crystal, rotation polarisation optical splitter 360 degree, the Changing Pattern figure of power output
Fig. 7 is linear polarization and the ratio of non-linear polarization laser output power and the graph of a relation of pump power of [111] and [100] cut direction Nd:YAG rod
Embodiment
As shown in Figure 1, the present invention is made of completely reflecting mirror (1), polarisation optical splitter (2), semiconductor laser pumping module (3), laser medium (4) and outgoing mirror (5), thermal stress birefringence effect below in conjunction with [111] and [100] direction cutting Nd:YAG crystal, and the hot fevering sodium effect that is produced, the inventive method is described further.
When not adding the polarisation optical splitter, diode-end-pumped [100] direction cutting Nd:YAG crystal bar, the laser of 1064nm under the generation random polarization state.Need the laser of linearly polarized light beam for running,, need in resonant cavity, add the device that polarisation optical splitter etc. can produce linearly polarized light this moment, as shown in Figure 2 such as electric-optically Q-switched, frequency multiplication and light beam external modulation etc.For [100] direction cutting Nd:YAG crystal, there are certain relation in hot depolarization direction and crystal-cut orientation, and the direction that changes linear polarization just can find the direction of hot depolarization minimum, and the hot depolarization on this direction is less than the hot depolarization of [111] direction Nd:YAG rod.So in rotation polarisation optical splitter, seek the polarization direction of peak power output, the hot depolarization minimum on this direction by the variation of observing laser power.
Operation principle is as follows: the refractive index of operation material can be used up the rate body surface and be shown that the minor variations of its shape, size and direction can characterize with the variations in refractive index that strain causes, i.e. index ellipsoid.[111] and [100] direction cutting Nd:YAG have cubic crystal structure, thereby optical isotropy, its indicatrix is a ball, but becomes ellipsoid under the effect of stress.In bar-shaped Nd:YAG crystal, laterally thermal stress is radially and tangential distribution, with local indicatrix identical direction axially arranged.I.e. every bit in excellent cross section, the main shaft of thermally induced birefringence all is radially and tangential distribution, square being directly proportional of birefringence size and radius.Therefore, the linearly polarized light beam by the Nd:YAG rod very big depolarization can occur and shakes.In the plane of vertical bars axle a bit
The radial refractive index component of this point is n
r, n
rBecome with the y axle
Angle and perpendicular to tangential refractive index component
That supposes incident light a bit resolves into two components, is parallel to n respectively
rWith
Because
So have phase difference between two components, elliptical polarization will take place in light.
As shown in Figure 3, for the Nd:YAG crystal of [111] cut direction, the x axle in excellent cross section respectively with the shake angle of direction of the angle theta of the characteristic vector of one of birefringence direction and depolarization
Size is identical, and promptly lattice structure is axially symmetrical along rod,
Its size is irrelevant with bullet light tensor size, and the direction that changes linear polarization can not change the size of hot depolarization.But for the Nd:YAG crystal of [100] cut direction, as shown in Figure 4, these two angles are unequal, promptly
Its size is relevant with bullet light tensor size, so change the size that the direction of linear polarization will change hot depolarization.
The polarization output laser of two laser bars of experiment contrast identical parameters, identical parameters refers to: the doping content of [100] and [111] cut direction Nd:YAG rod is identical 1.1%, identical, the excellent long 120mm of excellent diameter 3mm is identical, pump cavity is identical, resonator mirror is identical, the polarisation optical splitter is identical.To [100] cut direction Nd:YAG rod, in resonant cavity, behind the adding polarisation optical splitter, change the direction of linear polarization, found the direction of a hot depolarization minimum, and rotated by 5 ° interval, measure the output polarization luminous power; To [111] cut direction Nd:YAG rod, in resonant cavity, behind the adding polarisation optical splitter, change the direction of linear polarization, the output polarization luminous power is measured power as shown in Figure 5 not with change of polarized direction.
As shown in Figure 6, when the interval by 5 ° rotates the polarisation optical splitter during one week, can detect four minimums and max line polarised light power output respectively, the extreme value size is all identical.Relatively the linear polarization laser output power curve of [100] and [111] cut direction Nd:YAG rod can observe the former power output of linear polarization and be higher than the latter; [100] and the hot depolarization ratio of [111] cut direction Nd:YAG rod keep relative stability, curve as shown in Figure 7, both differ and surpass 20%, illustrate use [100] cut direction than [111] cut direction Nd:YAG rod as laser medium, in specific polarization direction, can reduce hot fevering sodium effect, improve the power output of laser linear polarization.
Claims (5)
1. improve the device of bar-shaped Nd:YAG crystal laser linearly polarized light power output, place the formation laserresonator by completely reflecting mirror (1), laser medium (4) and outgoing mirror (5) order, laser medium (4) is installed in the semiconductor laser module (3), and semiconductor laser module (3) profile pump laser medium (4) produces laser.It is characterized in that: described laser medium (4) is to use the Nd:YAG crystal bar of [100] cut direction, is provided with the polarisation optical splitter (2) of the linearly polarized laser that can make laser output P polarisation between laser medium (4) and the completely reflecting mirror (1).
2. according to the device of the bar-shaped Nd:YAG crystal laser of claims 1 described raising linearly polarized light power output, it is characterized in that: the Nd:YAG crystal bar as [100] cut direction of laser medium (4) is fixedly mounted in the laser cavity.
3. according to the device of the bar-shaped Nd:YAG crystal laser of claims 1 described raising linearly polarized light power output, it is characterized in that: polarisation optical splitter (2) is made up of two right-angle prisms, has wherein plated the dielectric multilayer light polarizing film on one the inclined-plane.
4. according to the device of the bar-shaped Nd:YAG crystal laser of claims 1 described raising linearly polarized light power output, it is characterized in that: polarisation optical splitter (2) can replace with other polarizing device that can produce linearly polarized light, comprises deielectric-coating flat-plate polarizing light microscopic.
5. use the method for the bar-shaped Nd:YAG crystal laser of claims 1 described raising linearly polarized light power output device, it is characterized in that: in adjustment process, the polarisation optical splitter (2) that is provided with between rotary laser medium (4) and the completely reflecting mirror (1), in the rotation adjustable range of 360 degree, there is the period of change of four linearly polarized light power outputs, four power maximum and minimum are arranged respectively; Choose wherein that the direction of any one power output maximum that is to say the direction of the direction of minimum thermal depolarization as the polarisation optical splitter, be implemented under the laser free oscillation condition raising of bar-shaped Nd:YAG crystal laser linearly polarized light power output.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102570282A (en) * | 2012-02-17 | 2012-07-11 | 北京工业大学 | Device and method for increasing linearly polarized light output power of neodymium (Nd): yttrium aluminum garnet (YAG) laser |
| CN103414101A (en) * | 2013-08-14 | 2013-11-27 | 北京工业大学 | Method and device for improving output characteristic of Nd:YAG passively-Q-switched laser |
| CN105140772A (en) * | 2015-09-30 | 2015-12-09 | 中国科学院合肥物质科学研究院 | Electro-optic Q-switch capable of completely compensating for laser thermal depolarization |
| CN107132673A (en) * | 2017-07-19 | 2017-09-05 | 中国工程物理研究院激光聚变研究中心 | A kind of device for eliminating electro-optic crystal depolarization |
| CN113310905A (en) * | 2021-05-22 | 2021-08-27 | 中国科学院理化技术研究所 | Device and method for measuring thermal stress in high-power laser cavity |
| CN115621820A (en) * | 2022-12-06 | 2023-01-17 | 武汉光谷航天三江激光产业技术研究院有限公司 | Linear polarization output laser structure for effectively compensating thermal depolarization effect |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3914710A (en) * | 1974-05-06 | 1975-10-21 | Sanders Associates Inc | Polarized continuous wave crystalline laser |
| EP0579998A1 (en) * | 1992-07-20 | 1994-01-26 | Hitachi, Ltd. | Solid-state resonator |
| CN101242070A (en) * | 2008-02-15 | 2008-08-13 | 福州高意通讯有限公司 | Solid laser of semiconductor pumping |
-
2011
- 2011-06-02 CN CN 201110147802 patent/CN102244341A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3914710A (en) * | 1974-05-06 | 1975-10-21 | Sanders Associates Inc | Polarized continuous wave crystalline laser |
| EP0579998A1 (en) * | 1992-07-20 | 1994-01-26 | Hitachi, Ltd. | Solid-state resonator |
| CN101242070A (en) * | 2008-02-15 | 2008-08-13 | 福州高意通讯有限公司 | Solid laser of semiconductor pumping |
Non-Patent Citations (2)
| Title |
|---|
| 《JOURNAL OF THE OPTICAL SOCIETY OF AMERICA》 19710630 W. KOECHNER et al. 《Birefringence of YAG: Nd Laser Rods as a Function of Growth Direction》 第758-766页 1-5 第61卷, 第6期 * |
| 《OPTICS EXPRESS》 20100913 Oliver Puncken et al. 《Intrinsic reduction of the depolarization in Nd:YAG crystals》 第20461-20474页 1-5 第18卷, 第19期 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102570282A (en) * | 2012-02-17 | 2012-07-11 | 北京工业大学 | Device and method for increasing linearly polarized light output power of neodymium (Nd): yttrium aluminum garnet (YAG) laser |
| CN103414101A (en) * | 2013-08-14 | 2013-11-27 | 北京工业大学 | Method and device for improving output characteristic of Nd:YAG passively-Q-switched laser |
| CN105140772A (en) * | 2015-09-30 | 2015-12-09 | 中国科学院合肥物质科学研究院 | Electro-optic Q-switch capable of completely compensating for laser thermal depolarization |
| CN105140772B (en) * | 2015-09-30 | 2018-05-15 | 中国科学院合肥物质科学研究院 | A kind of electro-optical Q-switch that laser heat depolarization is fully compensated |
| CN107132673A (en) * | 2017-07-19 | 2017-09-05 | 中国工程物理研究院激光聚变研究中心 | A kind of device for eliminating electro-optic crystal depolarization |
| CN107132673B (en) * | 2017-07-19 | 2023-09-26 | 中国工程物理研究院激光聚变研究中心 | Device for eliminating depolarization of electro-optic crystal |
| CN113310905A (en) * | 2021-05-22 | 2021-08-27 | 中国科学院理化技术研究所 | Device and method for measuring thermal stress in high-power laser cavity |
| CN113310905B (en) * | 2021-05-22 | 2022-06-24 | 中国科学院理化技术研究所 | Device and method for measuring thermal stress in high-power laser cavity |
| CN115621820A (en) * | 2022-12-06 | 2023-01-17 | 武汉光谷航天三江激光产业技术研究院有限公司 | Linear polarization output laser structure for effectively compensating thermal depolarization effect |
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Application publication date: 20111116 |