Low Loss TM-Pass Polarizer Fabricated by Proton Exchange for Z-cut Ti: LiNbO(3) Waveguides.

Many practical integrated optical LiNbO(3) devices, such as NxN switch arrays, operate on TM polarized light in Z-cut crystals to utilize the largest electro-optic coefficient, r(33). Because these devices are polarization sensitive, unacceptable levels of crosstalk can result from a small amount of the unwanted TE polarization component. The tolerances for aligning polarization maintaining fibers to these devices are therefore very tight. We report here on a TM-pass polarizer fabricated by proton exchange in Z-cut Ti:LiNbO(3) waveguides with a low insertion loss and high polarization extinction ratio of 0.3 dB and >40 dB respectively. This polarizer, when integrated into a Ti:LiNbO (3) device will reduce crosstalk and relax the polarization maintaining fiber alignment tolerances.