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

Abstract

A single-chip CMOS optical microspectrometer containing an array of 16 addressable Fabry-Perot etalons (each one with different resonance cavity length), photodetectors and circuits for readout, multiplexing and driving a serial bus interface has been fabricated in a standard 1.6 mm CMOS technology (chip area 3.9x4.2 mm2). The result is a chip that can operate using only four external connections (including Vdd and Vss) covering the optical range of 380-500 nm with FWHM=18 nm. Frequency output and serial bus interface allow easy multisensor, multichip interfacing using a microcontroller or a personal computer. Power consumption is 1250 mW for a clock frequency of 1 MHz