光子学报 ›› 2015, Vol. 44 ›› Issue (8): 819001-0819001.doi: 10.3788/gzxb20154408.0819001

• 非线性光学 • 上一篇    下一篇

Al、S和Te掺杂GaSe晶体的光学及倍频特性

冯志书1, 李晓明1, 于丹1, 康智慧2, 高锦岳2   

  1. 1. 空军航空大学, 长春 130022;
    2. 吉林大学 物理学院, 长春 130023
  • 收稿日期:2015-02-15 修回日期:2015-05-07 出版日期:2015-08-25 发布日期:2015-08-25
  • 作者简介:冯志书(1984-),女,讲师,博士研究生,主要研究方向为非线性光学.Email:zhishu_feng@163.com;高锦岳(1940-),男,教授,学士,主要研究方向为激光物理和量子光学.Email:jygao@jlu.edu.cn
  • 基金资助:

    国家重点基础研究发展计划项目(No.2011CB921603)资助

Optical and Second Harmonic Properties in Al, S and Te Doped GaSe Crystals

FENG Zhi-shu1, LI Xiao-ming1, YU Dan1, KANG Zhi-hui2, GAO Jin-yue2   

  1. 1. Aviation University of Air Force, Changchun 130022, China;
    2. College of Physics, Jilin University, Changchun 130023, China
  • Received:2015-02-15 Revised:2015-05-07 Online:2015-08-25 Published:2015-08-25

摘要:

对不同浓度Al、S和Te掺杂GaSe晶体的透过率和倍频特性进行了研究.结果表明,适宜浓度的掺杂晶体在透明波段内吸收系数约为α≤0.1~0.2 cm-1,适于非线性应用.GaSe:S晶体透过率曲线向短波方向移动,且更适于高浓度掺杂,而Al和Te掺杂晶体透明范围的波段截止波长向长波方向移动,且移动幅度小于S掺杂晶体,当掺杂浓度达到GaSe:Al (0.5 mass%)和GaSe:Te (5 mass%)时,晶体光学质量明显下降.通过fs Ti:Sapphire激光和CO2激光泵浦下I类倍频实验发现,S掺杂晶体相位匹配曲线向短波方向移动,倍频输出功率比纯GaSe晶体有明显提高,最佳掺杂浓度为2 mass%.Al和Te掺杂晶体相位匹配角与纯GaSe晶体相比没有明显变化,实验结果与理论曲线符合较好.利用非线性方法研究发现当掺杂浓度不超过5 mass%时,GaSe:Te晶体与纯GaSe同样属于六角形结构.三种掺杂方式最佳掺杂浓度分别为GaSe:Al (0.1 mass%),GaSe:S (2 mass%)和GaSe:Te(0.5 mass%),在CO2激光泵浦下,三者频率转换效率之比约为1:0.6:0.5.在所使用的晶体样本中,GaSe:S (2 mass%)晶体性能最佳,其频率转换效率可达纯GaSe晶体的3倍左右.

关键词: 非线性光学, 晶体, 掺杂, GaSe, 倍频, 相位匹配, 透过率

Abstract:

The transparency and second harmonic properties of Al, S and Te doped GaSe crystals were studied. Low absorption coefficients of α≤0.1~0.2 cm-1 are found in crystals with suitable doping level in transparent range which can be used in nonlinear devices. High doping level is allowed in GaSe:S crystals whose transparency spectra shift towards to short-wavelength range. The short wavelength transparency cut-off of both Al and Te doped crystals shifts more slowly than S doped crystals towards to opposite direction. The optical quality of the crystals has declined markedly when the doping concentration up to GaSe:Al (0.5 mass%) and GaSe:Te (5 mass%). The phase matching curves shift towards to short-wavelength and output power is significantly higher in S doped GaSe crystals than that in pure GaSe crystals with fs Ti:Sapphire laser and CO2 laser pumping. The optimal doping concentration is ascertained as 2 mass%. No obvious differences of type I second harmonic phase matching angle between Al, Te doped and pure crystals are found. The experimental results are in good agreement with theoretical curve. GaSe:Te crystals are found to possess the hexagonal structure like ε-GaSe when the doping concentration is no more than 5 mass% with nonlinear method. The SHG efficiency ratio of the optimal doped crystals GaSe:Al (0.1 mass%), GaSe:S (2 mass%) and GaSe:Te (0.5 mass%) is about 1:0.6:0.5 under CO2 laser pumping. GaSe:S (2 mass%) crystal shows the best performance whose efficiency is about 3 times higher than that in pure GaSe among all used samples.

Key words: Nonlinear optics, Doped, GaSe, Transparency, Second harmonic, Phase matching, Crystal

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