Optical Frequency Comb-based Calibration System
Recent cosmological observations suggest that the universe’s expansion is accelerating. Several lines of evidence corroborate this, including results from distant supernovae, the cosmic microwave background, and the clustering of matter. In the following we outline a new method based on direct frequency measurements of the cosmological redshifts. We have applied so called Optical Frequency Combs for the calibration of a traditional spectrograph in order to explore deep space more accurately than anybody before.
Out of the approximately 500 000 available frequency lines from the comb we only just used a total of 58 lines in the first trial at the Vacuum Tower Telescope at Tenerife. Although the telescope was not designed for this purpose, we readily achieved a state-of-the-art calibration accuracy.