第24卷第5期 光电工程 Vol. 24,No. 51997年10月 Opto-Electronic Engineering Oct, 1997(q%8;赵长明魏光辉(v;, 100081)K1本文首先概述了内含热透镜的激光谐振腔的分析方法,提出影响高平均功率固体激光器光束质量的主要因素是激光介质的热效应,尤其是非对称的热透镜象差。因此,改善光束质量的途径是补偿或修正透镜象差,使光束质量达到非相干多模振荡的理论值。实验研究了一种新型谐振腔四镜不失调反射镜腔的光束质量,结果表明比对应的平平腔光束质量明显提高,说明这种腔型在改善光束质量方面有良好前景。同时也说明上述改善光束质量的思想是正确的。5M固体激光器,高功率激光器,光束质量,象差校正。s|TN 248. 1An Investigation on the Improvement of the Beam Qualityof High Average PowerSolid-State LasersZhao Changming, Wei Guanghui(Department of OptoelectronicEngineering,BeijingInstituteof Technology,Beijing, 100081)AbstractAn analysis method for laser resonator with an internal thermal lens hasbeen summarized in the paper. T he thermal effect of laser medium, especially theasymmetric aberration of thermal lens, are the main factors that influence the beamquality of high average power solid-state lasers. The approach for improving beamquality is to compensate or correct thermal lens aberration and let the beam qualityreach the theoretical value of incoherent multi-mode oscillation. T he beam quality ofa novel resonatorifour mirror non-misalignment resonator has been investigatedexperimentally. T he results show an obvious improvement compared with the beamu:3, 1960M73, 1993M9?vpV,Cv;VYpVb;VYV;N#?;a;d0KVaF;a;3r,?VV,-TZ_(q%8;bl: 1995- 12- 02;l: 1996- 11- 07quality of the corresponding plane-parallel resonator. T his demonstrates that theresonator has a good prospect in improving the beam quality. At the same time itshows that the above guiding thinking in improving the beam quality is correct.Subject termsSolid lasers, High-power lasers, Light beam quality, Aberration cor-rection.Classsification numberTN 248. 1(q%8;(-KNdnullYAG;)oa;8.aqaXT%+(aSUaa;F)(Maoa)auSa)5QFDove8(q%8;sLTbTV,(q%8;i8M1,;A4b1=ci;8s1. 1(,(#rL!/,VB.ZV;s 1T(r) = T(r0) + Q4K (r20 - r2) ( 1)T(r0)V,r0bIn|qM#wqM8r,VrTf = KAPa12dndT + nullCr, nulln30 + nullr0(n0 - 1)L- 1( 2)TA;Pa;CraCnull;f,_M_511997年10月u:(q%8;,V7|CC;Vr,NdnullYAG,|qMi1y,|qMPM20%,rl6%b( 2)TVnf = MP- 1in ( 3)1,qb1. 2=ci;8s1. 2. 1内含热透镜的激光谐振腔模型图1含有热透镜的谐振腔模型Fig. 1Resonator model with a thermal lens=ci;8nm1,VV8+ 2, 3:Diiiy;,D= 1fnull1, 2ii8wqd1, 2ii8i,h1= h2= l2n,lbb8( D= 0)ggi = 1 - (d1 + d2) /nulli ( 4)7ci8Ng*ig*i = gi - Ddj( 1 - di/nulli) ( 5)N8NwqVg*ig*i = 1 - L* / null*i ( 6)L* = d1 + d2 - Dd1d2 ( 7)null*i = nulliL* / (Ddjnulli + L* ) ( 8)g*iV|=ci8Nb8,g*i8gumbMgN8b8i88M;null2i = null0L*nullg*jg*i ( 1 - g*1 g*2 )1/ 2( 9)8=,;bBf/,b8B%,7i8=;%,WiM1b;iM1b1. 2. 2基横模运转8Vci8Hq/8=;%#?null20i = null0L*nullg*1 g*2 ( 1 - g*1 g*2 ) 1/ 2g*j (L* /nulli) 2 + g*i ( 1 - g*1 g*2 ) ( 10)L0i = L* g*j (L* /nulli)g*j (L* /nulli) 2 + g*i ( 1 - g*1 g*2 ) ( 11)52;第24卷第5期null20i = null0nullL* g*j ( L* /nulli) 2 + g*i ( 1 - g*1 g*2 )g*1 g*2 ( 1 - g*1 g*2 ) 1/ 2 ( 12)L0i%8i,L0i 0VU%8=,L0i r0,i$9v,KP;TbB8,;?KvKlsYnulli,l = r0/ (di - L0i) ( 20)nulli,s = null0/nullnullr0 ( 21)Kl?MKlK?,7Kv?M+;?b531997年10月u:(q%8;2(q%8;2. 1;#kZE;+#5,;B1?S,S=SF( ISO);rbq,/,;VdoibyN,(q%8;o(,$,i#|rb3