Pyroelectric effects in LiNbO3 channel-waveguide devices

The thermal stability of Ti-indiffused LiNbO3 channel-waveguide devices is described. In Z-cut interferometers the pyroelectric effect causes large output instabilities. However, both Z-cut directional couplers and X-cut interferometers show good thermal stability. We discuss the pyroelectric effect and explain device thermal behavior. We describe the decay of induced voltage or of change in interferometer phase bias after a temperature change and deduce that LiNbO3 resistivities can be electric field dependent.