Low-crosstalk passive polarization splitters using Ti:LiNbO3 waveguide crossings

In this letter the first demonstration of low-crosstalk passive polarization splitters based on Ti: LiNbO3 single-mode waveguide crossings is reported. Polarization crosstalk of less than −20 dB for both polarizations and total insertion loss figures of −2.5 dB (TE) and −3.0 dB (TM) at λ=1.3 μm have been achieved by optimizing the design and the fabrication of the intersection area. The devices operated nearly wavelength independent (±0.3 dB) over a range of 100 nm.