On-chip integrated CMOS optical microspectrometer with light-to-frequency converter and bus interface

This single-chip CMOS microspectrometer uses fixed-cavity Fabry-Perot etalons with optical quality and long-term stability much higher than those of tunable devices. Many detectors are needed to cover a large optical spectral range with high resolution. Therefore, this single-chip microspectrometer contains an array of 16 addressable Fabry-Perot etalons, photodetectors and circuits for read-out, multiplexing and driving a sensor bus. This chip operates using only five external connections (including V,, and V/sub ss/) covering the optical range of 400-500 nm with FWHM=18 nm. Frequency output and serial bus interface allow easy multisensor, multi-chip interfacing using a microcontroller.