<title>Microspectrometer system for the near-infrared wavelength range based on LIGA technology</title>

Abstract

In recent years, microspectrometer systems fabricated by the LIGA technology for use in the visible wavelength range increasingly made their way to the market. For spectral analysis in the infrared range, a highly transmissive hollow waveguide has now been developed and demonstrated successfully. In combination with linear detector arrays, the hollow waveguide microspectrometer allows to design portable near infrared spectrometer systems. Such a system has now been applied to evaluate the spectrum from 0.9 jim to 1 .15 tm in second order and from 1.15 im to 1.75 im in first order. Due to its outer dimensions of 54 x 36 x 7 mm3 and a low power consumption, it can be integrated in portable spectral analysis systems. It exhibits a high sensitivity (NEP below 1 1 pW) due to a fiber-optical entrance with a fiber core diameter of 300 rim. An indium-gallium-arsenide linear detector array based on a novel setup concept is incorporated in the system. Furthermore, units for pre-amplification of the signal and 16-bit AD conversion are contained. In the present paper, the setup and fabrication of the whole microspectrometer system, its optical features and the detectorspecific solutions are described. The fabrication process which is based on molded polymer parts is presented. Using the experimental results of the electro-optical tests and the polymer spectra measured, the performance of the system will be demonstrated.

Portable Spectroscopy

“…Starting almost 20 years ago, a number of prototype miniature spectrometers using MEMS techniques were constructed or proposed, [163][164][165][166][167] including Fourier transform spectrometers. [168][169][170][171] The most detailed work at that time on mid-IR FT-IR spectrometers was done by Kraft et al, at Carinthian Tech Research (CTR), who described a number of miniaturized spectrometers, including a spectrometer with a MEMS interferometer. [172][173][174][175][176] The key component was a resonantly driven micromirror, suspended on two long springs, and driven by interlocking comb-structured electrodes.…”

Micromanufacturing: A review—Part I

“…150 The master containing grating structures and mirror is prepared using XRL and all optical components are fabricated in a single step using hot embossing or injection molding. 151…”

NIR Imaging Spectroscopy Instrumentation: Looking Forward to 2020?

“…Miniaturised multichannel detectors embedding the grating, the waveguide and the detector are other types of MEMS-based spectrometers. Krippner et al 5 propose a MEMS-based microspectrometer using an InGaAs linear detector array and hollow waveguide. The final dimension of the moulded polymer device is 54 × 36 × 7 mm.…”