High power side face pumping 1525nm human eye safe waveband is from Raman laser
Technical field
The present invention relates to field of lasers, particularly relate to a kind of high power side face pumping 1525nm human eye safe waveband from Raman laser.
Background technology
1.5 mu m waveband lasers relatively other wave band of laser have comparatively high damage threshold to human eye, thus have eye-safe; In addition, it has the features such as Atmospheric Absorption is weak, scattering is little, thus in spectrum analysis, space/optical fiber communication and laser radar etc., has important application.This third-order non-linear process of stimulated Raman scattering is utilized to be the important method producing above-mentioned wave band of laser.
So far, solid Roman near 1.5 mu m wavebands reported, mostly adopt end pumping technique from Raman laser, adopt the solid Roman of this kind of pump technology, be that threshold value is low and conversion efficiency is high from the advantage of Raman laser, but owing to there being strong thermal lensing effect in working media, the stability of laser can be affected to a great extent.In addition, because this pump mode can only occur in laser crystal end face direction, the impact of Stimulated Light crystal end-face size is comparatively large, and total pump energy can be restricted, and therefore, end pumping is only applicable to the laser system of low-power pumping density.Often need high-power laser light source in actual applications, at this moment end-face pump solid laser is just difficult to meet the demands.LD side pumped solid laser device can make full use of laser medium due to it, and the thermal effect of laser medium is relatively low, is conducive to obtaining high-power Laser output and draws attention gradually.Document " Diode-side-pumped Nd:YAG/BaWO
4dual-wavelength Raman laser emitting at 1502and 1527nm " (optical communication OC 306,165-169,2013) report with BaWO
4for the profile pump human eye safe waveband solid state laser of Raman medium.The maximum gross output obtained under 125W pump power is 2.3W.2014, the people such as Yumeng Liu were at " Diode-side-pumped actively Q-switched Nd: YAP/YVO
4multi-Watt first-Stokes laser " report the 1525nm side-pumped laser that power output is 4.5W in (optical engineering Optical Engineering 53 (6), 2014).
Inventor is realizing in process of the present invention, finds at least there is following shortcoming and defect in prior art:
What side pumped solid laser device all adopted is the structure that gain medium is separated with Raman medium, by Raman medium produces Raman light after producing fundamental frequency light by side-pumped laser gain media.The shortcoming of this kind of structure makes laser cavity structure become complicated, not easily regulate, and the beam quality due to the fundamental frequency light now produced is poor causes follow-up fundamental frequency light very low to the conversion efficiency of Raman light, thus is difficult to export good raman laser.
Summary of the invention
The invention provides a kind of high power side face pumping 1525nm human eye safe waveband from Raman laser, the invention solves end pumping Raman laser power output low, resonant cavity structure for side-surface pumping solid laser is complicated, conversion efficiency is low, beam quality difference and the problem such as power output is undesirable, described below:
A kind of high power side face pumping 1525nm human eye safe waveband is from Raman laser, and described laser comprises: laser, Raman light total reflective mirror, acousto-optic Q modulation switch, side pump head and Raman light outgoing mirror;
Described side pump head comprises: LD array and laser crystal bar, and described LD array is used for laser crystal bar described in pumping, and described laser crystal bar is used for Laser emission and stimulated Raman scattering;
Described laser crystal bar and described acousto-optic Q modulation Switching Two end face plating 1000-1600nm anti-reflection film; The plating of described laser, Raman light total reflective mirror 1064nm high transmittance film and 1342,1525nm high-reflecting film; Described Raman light outgoing mirror plating 1064nm high transmittance film, 1342nm high-reflecting film and 1525nm component permeate film;
Described LD array, described laser crystal bar operate in the resonant cavity that described laser, Raman light total reflective mirror and described Raman light outgoing mirror form, realize fundamental frequency light starting of oscillation, and fundamental frequency light is realized to Raman light conversion through described acousto-optic Q modulation switch under described laser crystal bar effect, described Raman light outgoing mirror exports 1525nm laser.
Preferred described LD array is evenly distributed in described laser crystal bar side, and described LD array is for realizing the uniform pumping to described laser crystal bar.
Further, described laser crystal bar is specially: Nd:YVO
4crystal bar or Nd:GdVO
4crystal bar.
The beneficial effect of technical scheme provided by the invention is: it is low that the present invention had both solved end-face pump solid laser power output, the problem that practicality is poor, solves again common side pumped solid laser device complex structure and other problems.For building high power, the Raman light laser of high conversion efficiency provides a kind of excellent scheme.To practical application and experimental study all significant.
Accompanying drawing explanation
Fig. 1 is the structural representation of a kind of high power side face pumping 1525nm human eye safe waveband from Raman laser;
Fig. 2 is the structural representation of side pump head.
In accompanying drawing, the list of parts representated by each label is as follows:
1: laser, Raman light total reflective mirror; 2: acousto-optic Q modulation switch;
3: side pump head; 4: Raman light outgoing mirror;
31:LD array; 32: laser crystal bar.
Embodiment
For making the object, technical solutions and advantages of the present invention clearly, below embodiment of the present invention is described further in detail.
For Problems existing in background technology, the embodiment of the present invention proposes and adopts profile pump from Raman laser structure, namely be there is by LD array side pumping one crystal bar of Its Gain Property and Raman active simultaneously, thus the raman laser obtaining required wave band exports.This design makes cavity configuration become compact, and conversion efficiency improves greatly, thus obtains high-power Laser output.
A kind of high power side face pumping 1525nm human eye safe waveband is from Raman laser, and see Fig. 1, laser comprises: laser, Raman light total reflective mirror 1, acousto-optic Q modulation switch 2, side pump head 3 and Raman light outgoing mirror 4.See Fig. 2, side pump head 3 comprises: LD array 31, laser crystal bar 32.
Wherein, laser crystal bar 32 and acousto-optic Q-switch 2 Double End plating 1000-1600nm anti-reflection film; Laser, Raman light total reflective mirror 1 plate 1064nm high transmittance film and 1342,1525nm high-reflecting film; Raman light outgoing mirror 4 plates 1064nm high transmittance film, 1342nm high-reflecting film and 1525nm component permeate film.
See Fig. 2, be encapsulated in LD array 31 (namely LD array 31 is evenly distributed in laser crystal bar 32 side) in side pump head 3 and realize the uniform pumping to laser crystal bar 32.
Side pump head 3 (LD array 31, laser crystal bar 32 two parts) operates in the resonant cavity that laser, Raman light total reflective mirror 1 and Raman light outgoing mirror 4 form, realize fundamental frequency light (1342nm) starting of oscillation, and regulated fundamental frequency light to change this third-order non-linear process to Raman light, finally by the 1525nm laser of Raman light outgoing mirror 4 output high-power through acousto-optic Q modulation switch 2 under laser crystal bar 32 self-acting.
Wherein, laser crystal bar 32 can be Nd:YVO
4crystal bar also can be neodymium-doped gadolinium vanadate (Nd:GdVO
4) etc. can launch the conventional from Raman medium of required wave band raman laser, during specific implementation, the embodiment of the present invention does not limit this.
Wherein, raman laser drive manner can be modulation, drive manner such as tune Q or locked mode etc., and during specific implementation, the embodiment of the present invention does not limit this.
Wherein, forming the laser of laserresonator, Raman light reaction mirror 1 and Raman light outgoing mirror 4 can be flat mirror, and also can be the eyeglass of the different curvature such as concave mirror and convex lens, laserresonator can adopt two mirror chambeies also can be many mirrors chamber, during specific implementation, the embodiment of the present invention does not limit this.
The embodiment of the present invention is to the model of each device except doing specified otherwise, and the model of other devices does not limit, as long as can complete the device of above-mentioned functions.
It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the invention described above embodiment sequence number, just to describing, does not represent the quality of embodiment.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.