Electric-field-controlled optical switch using Kerr effect and gradient of the composition ratio Nb/(Ta + Nb)

Abstract By exploiting the Kerr effect and the gradient of the composition ratio m , Nb/(Ta + Nb) in mol%, in KTa 1− x Nb x O 3 (KTN) crystals, we have designed an electric-field-controlled optical switch. The operating principle of the switch is described. During the switching process, the incident linearly polarized beam is orthogonally deflected as it propagates through the crystals. The g 11 / g 12 ratio (>10), wavelength range (491–1064 nm), I – V characteristics (0–800 V), extinction ratio (0–1), gradient of Curie temperature (21–22.9 °C), response time that may be in ns order, and influence of the photorefractive effect were studied. The results show that our design provides a new kind of optical switch with macro scale (mm order), adjustable extinction ratio (0–1), wide wavelength range (491–1064 nm).