THIS: a tuneable heterodyne infrared spectrometer

We present the newly developed transportable setup of the Cologne Tuneable Heterodyne Infrared Spectrometer (THIS) designed for astronomical observations aboard the Stratospheric Observatory For Infrared Astronomy (SOFIA). With THIS a competitive tuneable heterodyne spectrometer for the mid-infrared is available that will allow measurements in a wide field of astronomical applications. Frequency tuneability over a wide range provided by the use of semiconductor lasers as local oscillators (LO) allows a variety of molecules in the mid infrared to be observed under very high frequency resolution. With the use of newly developed quantum-cascade lasers (QCL) a sensitivity close to the quantum limit will be in reach.