In this letter, we report on fabrication and characterization of the first
zeroth-order half-wave plates of LiNbO3 obtained by crystal ion slicing (CI
S), Polarization rotation was demonstrated in 10-mum-thick freestanding LiN
bO3 films with 30-dB conversion ratios and negligible material loss. Polari
zation-independent performance was demonstrated in a hybrid-optic device co
mprising a CIS wave plate integrated with single-mode silica-based channel
waveguides.