Widely tunable micromachined optical filter with adjustable tuning characteristics

We designed a new tunable filter with a top DBR structure of Al/sub 2/O/sub 3//GaAs and demonstrated a tunable filter using this design. Adjustable tuning characteristics were achieved by removing excess nitride, providing greater yield during the release process, as well as being able to achieve a flexible structure afterward. The mechanical and optical measurements both demonstrate realization of a narrow linewidth, broad tuning range optical filter.