Orientation dependence of photorefractive gain in BCT: determination of electrooptic coefficients

摘要

Photorefractive two-beam coupling measurements as a function of the orientation of the grating spacing at 514 nm have enabled us to precise the values of the electrooptic coefficients of BCT. We find r_(13)~T = 33pm.V~(-1) and r_(33)~T = 170pm.V~(-1). These values are in good accordance with other published values. For the interesting coefficient r_(42)~T, we find a higher value r_(42)~T = 465pm.V~(-1) than the one previously published. The observation of beam-fanning and the fact that we have been able to implement a DPCM in a 45°-cut BCT (and not in a 0° cut crystal) confirms that the electrooptic coefficient r_(42)~T is higher than r_(33)~T.