MINIATURE SPECTROMETERS FOR BIOCHEMICAL-ANALYSIS

Miniature spectrometers have been demonstrated by mounting micromachin ed diffraction gratings onto CCD imaging devices. Two implementations are tested: one for high-dispersion and -sensitivity applications, and the other for low-cost consumer applications. The first system shows a dispersion of 1.7 nm/pixel and a resolution of 74.4 for the bandwidt h of interest. The free spectral range of the device is designed to be in the visible range for this particular application. The diffraction efficiency of the system is 63%. The second, low-cost system demonstr ates a dispersion and resolution of 2.55 nm/pixel and 69.8, respective ly. These specifications are comparable to that of a conventional, low -end commercial spectrometer. Results are shown for their applications in biochemical analysis. Further optimization is sought by adding mic romachined lenses and creating specialized, computer-generated grating s to compress and shape the spectral signal.