MICROSPECTROMETER FABRICATED BY THE LIGA PROCESS

The Liga process can be used to pattern light guiding polymer layers w ith high accuracy, enabling planar grating spectrographs with self-foc using reflection gratings consisting of step heights as small as 0.2 m u m with a total structure height of 125 mu m to be fabricated. These grating spectrographs can be used for optical analysis over the entire visible and near infrared (up to 1100 nm) wavelength regions; the tra nsmitted intensity is about 25%. They can be adapted easily to a diode array by using total internal reflection at an inclined sidewall also fabricated by the Liga process. In this case the spectral resolution may be in the order of 1-4 nm per diode pixel.