<title>Miniature spectrometers for biochemical analysis</title>

Abstract

Miniature spectrometers were demonstrated by mounting micromachined diffraction gratings onto CCD imaging devices. Two implementations were tested: one for high dispersion and high sensitivity applications, and the other for low-cost consumer applications. The first system showed a dispersion of 1.7 nm/pixel and a resolution of 74.4 for the bandwidth of interest. The free spectral range of these devices was designed to be in the visible range for this particular application. The diffraction efficiency of the system was 63%. The second, low-cost system demonstrated a dispersion and resolution of 2.55 nm/pixel and 69.8 respectively. These specifications are comparable to that of a conventional, low-end commercial spectrometer. Results are shown for their applications in biochemical analysis. Optimization was sought by adding micromachined lenses and creating specialized, computer generated gratings to compress and shape the spectral signal.