SUPPRESSION OF THERMAL DRIFTS OF HIGH-SPEED TILINBO3 OPTICAL MODULATORS

The thermal-drift behavior of interferometric modulators with Mach-Zeh nder structures are experimentally shown to be remarkably improved bec ause of the introduction of proper asymmetry into the optical waveguid e arms. These experimental results are theoretically explained taking the effects of asymmetric waveguides and pyroelectric charges into acc ount. It is found that the optical output follows the sinusoidal squar ed variation with temperature and the proper introduction of asymmetri c waveguide arms is helpful in the adjustment of the slope at its oper ating points. It is, therefore, concluded that the thermal drifts of T i:LiNbO3 optical modulators can be suppressed by minimizing the gradie nt of the output due to temperature variations.