Integrated InGaAsP MQW Mach–Zehnder modulator

We demonstrate the use of an area selective zinc in-diffusion process as a simple and efficient technique for the fabrication of integrated photonic devices. By controlling the profile of the diffusion front and the zinc depth the insertion losses of the devices can be minimized. Using this technique an integrated 1×2 Mach–Zehnder analog modulator was fabricated. Our experimental results demonstrate that the modulator exhibits excellent linearity for both TE and TM polarizations over a wavelength range of 40 nm. The measured on-chip losses in the order of 3 dB are obtained, which is significantly lower compared to the use of isolation trenches.