FABRICATION AND ANALYSIS OF HIGH-CONTRAST INGAASP-INP MACH-ZEHNDER MODULATORS FOR USE AT 1.55-MU-M WAVELENGTH

A high-contrast ratio, low voltage-length product, multiple quantum we ll InGaAsP-InP Mach-Zehnder interferometer is demonstrated and analyze d. An on/off ratio of over 40 dB and voltage-length product of 1.8 V-m m were measured, results which are superior to previous reports of sim ilar MQW structures. Using the Lanczos-Helmholtz beam propagation meth od, we find that the linear and quadratic electrooptic coefficients fo r InGaAsP quantum wells are r = (3.9 +/- 1.7) pm/V and s = (5.0 +/- 1. 5) x 10(-19) m(2)/V-2, respectively. We also demonstrate active optica l alignment of the modulator guides using integrated waveguide light e mitting diodes.