Integrated silicon microspectrometers

Abstract

Microspectrometers, which read color and the results from analytical chemistry, are used for quality inspection in industry and agiculture. They read the chromatography results by measuring the infrared (IR) absorption of the chemical constituent between the IR source and the grating. Micromachining can implement the dispersion and detection elements in a silicon microspectrometer so that it can analyze the spectrum of incident light. The microspectrometer may either operate an array of detectors, each with a uniform spectral response, or scan the dispersion element using a single calibrated detector. Compared to bulky macroscopic devices, this microspectrometer has inferior spectral resolution but its small size and low cost more than compensates for this limitation in many applications.