Micromachined GaAlAs/GaAs vertical cavity for multiple wavelength filter and VCSEL array

Tunable filters and lasers are key devices for future all optical networks. A tunable Fabry-Perot filter or vertical cavity surface emitting laser (VCSEL) has been demonstrated with a micromachined distributed Bragg reflector (DBR). Various advantages including wide wavelength tuning range, polarization insensitive operation and 2-dimensional array integration can be expected for such micromachined devices. We proposed a temperature insensitive add/drop filter and VCSEL using a micromachined DBR mirror tuned by differential thermal expansion coefficients. We experimentally demonstrated its temperature insensitive operation, wavelength trimming of over 20 nm and 2-dimensional integration of multi-wavelength filters. There is a strong demand for increasing the number of wavelength in rapidly progressing WDM systems. In this paper, we scale up the 2-dimensional integration of multi-wavelength vertical cavities, demonstrating a 4×4 multiple wavelength micromachined GaAlAs-GaAs filter array