Theory and experiments of the one-mirror-inclined three-mirror-cavity photodetectors

Research on the one-mirror-inclined three-mirror-cavity (OMITMC) photodetectors in our laboratory is reported. In the structure of the photodetectors, it is the inclined- mirror that makes the filtering cavity and the absorption cavity decoupled, thus narrow spectral response linewidth, high-speed and high quantum efficiency can be achieved simultaneously. On the basis of the theoretical analysis, we do realize the vertical taper structure, the key part in the whole integrated device, by dynamic etch mask technique. Moreover, the first integrated device of this type was fabricated. A spectral response linewidth less than 6nm and a quantum efficiency of 52.6% have been achieved experimentally.