Improvement of the Optical Transmission of ZnGeP2 by Nuclear Radiation

本小企业创新研究一期项目旨在提高ZnGeP2晶体的光传输性能。ZnGeP2单晶在光学参量振荡器（opo）中具有最高的性能，可产生3至11微米的可调谐辐射。然而，ZnGeP2在1 ~ 3微米之间表现出异常吸收，这是泵送opo所需的光谱区域。这种吸收极大地限制了IR opo可以处理的平均功率。虽然我们发现对ZnGeP2晶体进行热退火可以将光透射率从1微米提高到3微米，但是提高的幅度不够大，并且需要过多的退火时间。INRAD, Inc.提出利用快速电子和伽马射线辐射来提高ZnGeP2的光透射率。

This Small Business Innovation Research Phase I project is directed to the improvement of the optical transmission of ZnGeP2 crystals. ZnGeP2 single crystals have the highest figure of merit for use in optical parametric oscillators (OPOs) to generate 3 to 11 micron tunable radiation. However, ZnGeP2 shows an anomalous absorption between 1 and 3 microns, which is the desired spectral region for pumping OPOs. This absorption sharply limits the average power that can be handled by IR OPOs. Although we have found that thermal annealing of ZnGeP2 crystals will improve the optical transmission from 1 to 3 microns, the improvement is not great enough, and it requires an excessive annealing time. INRAD, Inc., proposes to utilize fast electron and gamma ray radiation to improve the optical transmission of ZnGeP2.