Relaxation processes in a Bragg modulator structure made of lithium niobate

An investigation was made of dielectric relaxation in a controlled integrated-optics Bragg modulator, which resulted in the appearance of a low-frequency limit to the pass band. Steady-state relaxation, mainly due to ionic conductivity of the surface waveguide layer heavily doped with titanium, had a characteristic time of τ ~10^–1 – 10^–2 sec. Transient relaxation effects could result in greater changes in the relaxation time within the range 10³ – 10^–4 sec. An analysis of the possible mechanisms of transient relaxation was made.