Birefringence and piezo-Raman analysis of single crystal CVD diamond and effects on Raman laser performance

Defect-induced stress has been mapped in optical-grade synthetic diamond (chemical vapor deposition grown, low nitrogen, low birefringence) using Metripol polarimetry, Mueller polarimetry, and Raman microscopy. Large circular retardance was observed in the 8 mm long h110i cut crystal with values up to 28° for some paths along the major axis. Metripol-determined values for linear birefringence magnitude and fast-Axis direction in such regions have significant error. Stress-induced shifts in Raman frequency were observed up to 0.7 cm-1, which we deduce result from uniaxial and biaxial stresses up to 0.86 GPa. We also elucidate the effect of stress on diamond Raman laser performance. For high cavity Q Raman lasers, the direction of the linear birefringence axis is found to be a primary factor determining the laser threshold and the input-output polarization characteristics.