Er:YAP晶体多波长激光运转及偏振特性研究  

Investigation on the Multiwavelength Laser Operation and Polarization Characteristics of Er:YAP Crystal

作　　者：权聪 孙敦陆 罗建乔 张会丽 方忠庆 赵绪尧 胡伦珍 韩志远 程毛杰 殷绍唐 QUAN Cong;SUN Dun-lu;LUO Jian-qiao;ZHANG Hui-li;FANG Zhong-qing;ZHAO Xu-yao;HU Lun-zhen;HAN Zhi-yuan;CHENG Mao-jie;YIN Shao-tang(Anhui Key Laboratory of Photonic Devices and Materials,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China;Science Island Branch of Graduate School,University of Science and Technology of China,Hefei 230031,China;Science and Technology on Solid-State Laser Laboratory,North China Research Institute of Electro-Optics,Beijing 100015,China)

机构地区：[1]中国科学院安徽光学精密机械研究所光子器件与材料安徽省重点实验室,安徽合肥230031 [2]中国科学技术大学研究生院科学岛分院,安徽合肥230031 [3]华北光电技术研究所固体激光技术重点实验室,北京100015

出　　处：《光谱学与光谱分析》2020年第8期2325-2331,共7页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(51872290,51702322,51802307);国家重点研发计划项目(2016YFB1102301);固体激光技术重点实验室开放基金项目资助。

摘　　要：研究了b轴10 at.%Er∶YAP晶体的偏振吸收和输出特性以及多波长激光运转特性。首次测量了Er∶YAP晶体的偏振吸收光谱,结果显示晶体对偏振方向平行于a轴和c轴的偏振光在4I11/2能级对应的吸收峰附近的最大吸收系数分别为4.606 3 cm^-1(975.2 nm处)和2.936 6 cm^-1(967.6 nm处),因此选择合适波长的线偏振光作为泵浦光有利于提高晶体对泵浦光的吸收效率,从而改善激光性能;在氙灯泵浦的激光实验中,自由运转条件下实现了2 710,2 728,2 795和2 918 nm等4条谱线的激光输出,并分别研究了各谱线的偏振特性和起振的阈值特性。通过在谐振腔内加JGS石英片、云母片、 K9镜片等选择性吸收片分别实现了2 918 nm单波长, 2 710,2 821,2 837和2 862 nm等四波长和2 710 nm单波长的激光输出。测量了自由运转和不同选择性吸收片条件下的激光光谱,并与不同选择性吸收片的透过谱及之前报道的荧光光谱进行对照分析,证明通过调节谐振腔能够对Er∶YAP晶体中的起振谱线进行选择。偏振激光实验结果表明除谱线2 918 nm是偏振方向平行于a轴的线偏振光,谱线2 728 nm有时是偏振方向平行于c轴的线偏振光,有时又是偏振椭圆长轴平行于YAP晶体a轴的部分偏振光外,谱线2 710和2 795,2 821,2 837和2 862 nm均为偏振方向平行于c轴的线偏振光;在LD端面泵浦条件下,得到2 710,2 728,2 750和2 795 nm四条谱线的激光输出,其中谱线2 750 nm首次在Er∶YAP晶体中实现激光输出,这四条谱线均为偏振方向平行于晶体c轴的线偏振光;此外,首次测量了该晶体在8 K低温下的吸收光谱,利用Gauss函数对光谱进行分峰拟合,根据拟合结果对激光上下能级各斯塔克子能级进行了能级指认,并结合Er∶YAP晶体激光光谱、荧光光谱对可能的谱线跃迁进行了辨认。Er∶YAP晶体偏振特性和多波长讥光运转特性的研究以及对后续Er∶YAP晶体调Q等技术的实现和电光调In this paper, the polarization absorption and output characteristics and the multi-wavelength laser operation characteristics of 10 at.% Er∶YAP crystal are studied. The polarization absorption spectra of Er∶YAP crystal is measured for the first time, the result indicated that the maximum absorption coefficients of crystal to linearly polarized light parallel to axis a and axis c in the absorption peak corresponding to the 4I11/2 energy level are 4.606 3 cm^-1 (at 975.2 nm) and 2.936 6 cm^-1(at 967.6 nm), respectively. Therefore, the absorption efficiency of Er∶YAP crystal to pump light can be improved by choosing linearly polarized pump light with properly wavelength, which is conducive to improving the laser performance. In the xenon lamp pumped laser expeiments, four spectral lines of 2 710, 2 728, 2 795 and 2 918 nm are realized laser output under the free operation condition, the polarization and threshold characteristics of each spectral line are studied respectively. The laser output of single wavelength of 2 918 nm, four spectral lines of 2 710, 2 821, 2 837, 2 862 nm and single wavelength of 2 710 nm are achieved by adding JGS quartz plate, mica plate and K9 lens selective absorber respectively in the resonator cavity. The laser spectra are measured under the conditions of free operation and different selective absorbers, As well by contrasting with the transmittance spectra of different selective absorbers and the previously reported fluorescence spectra, it is proved that the oscillation is starting spectrum lines in Er∶YAP crystal could be selected by adjusting the resonator cavity. The experimental results show that the polarization direction of 2 918 nm spectral line is parallel to axis c and the polarization direction of 2728 nm spectral line sometimes parallel to the axis c and sometimes parallel to the axis a, besides, the polarization direction of all other spectral lines like 2 710, 2 795, 2 821, 2 837 and 2 862 nm are parallel to the axis c. The four laser spectral lines of 2 710, 2 72

关 键 词：掺铒铝酸钇晶体 偏振特性 多波长激光运转 能级指认 

分 类 号：TN248.1[电子电信—物理电子学]