Chen Peng, He Dongbing, Jin Yunxia, Chen Junming, Zhao Jingyin, Xu Jiao, Zhang Yibin, Kong Fanyu, He Hongbo
Opt Express. 2018 Jan 8;26(1):157-164. doi: 10.1364/OE.26.000157.
In this paper, we present a method for achieving precise evaluation of amplitude of refractive index modulation (RIM) inside the volume Bragg grating (VBG) recorded in photo-thermo-refractive (PTR) glasses. The Gaussian divergence characteristics of the incident beam is theoretically considered when calculating the angular selectivity of VBG, and the profiles of experimental angular selectivity curves are utilized to determine the value of RIM with one step. The effectiveness of our proposed method is experimentally verified. This method is applicable even if the full width at half maximum (FWHM) of VBG's angular selectivity curve has the same order of magnitude as or is less than the beam divergence.
在本文中，我们提出了一种方法，用于精确评估在光热折射（PTR）玻璃中记录的体布拉格光栅（VBG）内部的折射率调制（RIM）幅度。在计算VBG的角度选择性时，从理论上考虑了入射光束的高斯发散特性，并利用实验角度选择性曲线的轮廓一步确定RIM的值。我们所提出方法的有效性通过实验得到了验证。即使VBG角度选择性曲线的半高宽（FWHM）与光束发散具有相同的数量级或小于光束发散，该方法仍然适用。
