We report a single-mode P-P-p-i-n-N-N GaAs/AlGaAs W waveguide phase modulator with a high phase modulation efficiency and a low propagation loss. The phase modulator with a W-shaped refractive-index profile utilizes a novel epilayer structure to reduce the propagation loss associated with doped layers and to obtain a phase modulation efficiency larger than those of P-i-N double heterostructure modulators. The phase shift and propagation loss were measured with a Fabry–Perot resonance method at 1.31-μm wavelength. A phase modulation efficiency as high as 34.6°/V mm was measured for TE polarized light. Also propagation losses of less than 0.6 dB/cm were achieved. As a result, the W waveguide phase modulator that exhibits a high phase modulation efficiency and a low propagation loss have been experimentally realized for the first time as far as we know.
© 1998 Optical Society of America
Young Tae Byun, Kyung Hyun Park, Sun Ho Kim, Sang Sam Choi, Jong Chang Yi, and Tong Kun Lim, "Efficient Single-Mode GaAs/AlGaAs W Waveguide Phase Modulator with a Low Propagation Loss," Appl. Opt. 37, 496-501 (1998)