High-speed optical beam scanning using KTN crystal

500 kHz optical beam scanning with a full scan angle of over 100 mrad is demonstrated using a potassium tantalite niobate (KTa_1-xNb_xO₃, KTN) deflector. To suppress any heating of the KTN chips during the high frequency operation and to have a sufficient interaction length to achieve more than 100 mrad deflection, the deflector consists of two KTN chips each of which has a pentagon-shaped electrode surface whose longest side is shortened to 1.5 mm. The full scan angle of the deflector is measured and the KTN temperature dependence of the permittivity accounts for the voltage and frequency dependence of the scan angle.