Abstract

In many laser systems being proposed and developed for space-based applications, it is desirable to work at shorter wavelengths, thereby minimizing diffraction effects while enhancing receiver sensitivity. To take full advantage of current laser materials operating in the infrared, nonlinear crystals are used to convert the fundamental laser light to shorter wavelengths by means of second harmonic generation (SHG). Since this process is primarily a coherent scattering phenomenon, any defects that are created in the lattice due to radiation from the surrounding environment could adversely affect the overall conversion efficiency or otherwise modify the essential anisotropic optical properties of these materials. Experiments have been done on a commonly-used nonlinear material, deuterated potassium dihydrogen phosphate (KD*P) that show it to be insensitive to gamma radiation for doses up to 200 krads. Measurements on a more efficient material, potassium titanyl phosphate (KTP) are underway and will be reported on later.

© 1993 Optical Society of America