SUPPRESSION OF THERMAL DRIFTS OF HIGH-SPEED TILINBO3 OPTICAL MODULATORS

The thermal-drift behavior of interferometric modulators with Mach-Zehnder structures are experimentally shown to be remarkably improved because of the introduction of proper asymmetry into the optical waveguide arms. These experimental results are theoretically explained taking the effects of asymmetric waveguides and pyroelectric charges into account. It is found that the optical output follows the sinusoidal squared variation with temperature and the proper introduction of asymmetric waveguide arms is helpful in the adjustment of the slope at its operating points. It is, therefore, concluded that the thermal drifts of Ti:LiNbO3 optical modulators can be suppressed by minimizing the gradient of the output due to temperature variations.