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 – 104 sec. An analysis of the possible mechanisms of transient relaxation was made.