To investigate the beam dependence of a fiber-optic voltage sensor by using a LiNbO<sub>3</sub> crystal, I undertook a series of calculations of various beam conditions expressed as Gauss functions by using the plane-wave method, treating each linear electro-optic term as a perturbation of the birefringence of a uniaxial crystal caused by an off-axis beam. The approximation proved to be accurate to within 0.2%. I discovered that the performance of the sensor is closely dependent on the beam angle from the <i>z</i> axis and the beam angle on the x–y plane but that its fabrication requires an impractical degree of control of the collimated beam. I also found the optimal uncollimated beam condition, which provides immunity to temperature changes and variations in the direction of the propagating beam, compensating for the temperature dependence of the quartz 1/4 wave plate. The experimental data support the simulated results.
© 2001 Optical Society of America
Hidenobu Hamada, "Investigation of the beam dependence of a fiber-optic voltage sensor by use of a LiNbO3 crystal," J. Opt. Soc. Am. B 18, 444-456 (2001)