<title>Microspectrometer for the infrared range</title>

Abstract

By the LIGA technique it is possible to fabricate the optical part of a microspectrometer system for the NIR. It is based on a plate-type waveguide whereas on top of one of these plates a self-focusing reflection grating and structures for coupling in and out of the radiation are microstructured. Two prototypes, one for the wavelength range between 1.6 micrometer and 2.0 micrometer and the second for the range from 2.7 micrometer to 3.3 micrometer, have been fabricated and evaluated. The efficiency of both is in the range of 20%, the resolution is 9.8 nm, res. 34 nm. Both components have been designed in a way that they can be combined with a detector array. Thus it is evident that microspectrometer units without movable parts and sizes in the range of several cubic centimeter can be fabricated using LIGA technique. In the paper the fabrication process as well as the evaluated results are described.