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Toward very large bandwidth with acousto-optical spectrometers

DOI

11

Citations

0

References

2003

Year

Rudolf Schieder, O. Siebertz, C. Gál, Michael Olbrich, Frank Schloeder, R. Bieber, F. Schmuelling, Volker Tolls, J. Horn
Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Abstract

The present status of AOS development at KOSMA is discussed. A study of a new generation of AOS using the new Bragg-cell material "Rutil" is on the way, which is supposed to lead to spectrometers in the range of 4 GHz total bandwidth at an resolution of 2-3 MHz. A second alternative for a 4 GHz bandwidth spectrometer has been developed as an engineering model for the HIFI instrument aboard the ESA cornerstone mission "Herschel". It consists of an array-AOS with 1 GHz bandwidth of each of the four AOS bands at a resolution of 1 MHz. A hybrid system for an input between 4 and 8 GHz is setup, and various laboratory tests have demonstrated that this system is well suited for large bandwidth applications like with HIFI. For eventual future demand of even larger bandwidth, details of a new optical method for Rf-analysis are discussed. It consists of a modulated laser with one or two Fabry-Perot etalons to analyze the frequency distribution of the resulting laser sidebands. A bandwidth of several 10 GHz at moderate resolution can be achieved.