Detectors Based on Resonant Cavity

Abstract

In the SOI chapter, rather inefficient resonant cavity detectors with quantum efficiencies up to 27% were described. Here, a different approach, which is also appropriate for Si detectors with a bandwidth of several GHz, for the improvement of the quantum efficiency will be introduced. The efficiency improvement of the detectors can be achieved by an enhancement of the reflection coefficients on the top and bottom of the Si device layer by through the implementation of Bragg reflectors. In addition to the efficiency enhancement for selected wavelengths, the efficiency for other wavelengths is reduced to near zero by the implementation of Bragg reflectors. An example of a resonant cavity-enhanced Si detector with a quantum efficiency of 65% at 700 nm, optical bandwidth of 20 nm, and bandwidth of up to 5GHz will be discussed. Furthermore, an example of an RCE detector with a bandwidth of above 10 GHz will be described.