Custom Frequency Comb
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.
Frequency comb technology makes direct measurement of absolute optical frequencies possible. The FC1000 Optical Frequency Synthesizer is a compact, portable and flexible fiber-based femtosecond frequency comb system. The system is capable of providing at the same time a source for frequency metrology in both the visible and the near-IR regions (520-1040 nm) of the spectrum. A wide range of optional units enables us to tailor this versatile system to customer specific metrology solutions.
The FC800 is a Ti:Sapphire based Optical Frequency Comb with a mode spacing of 1 GHz. Its oscillator is the Laser Quantum taccor turn-key femtosecond laser. Menlo Systems’ robust and mature one-arm f-2f interferometer technology together with our optimized control loops and our established software packages for automation and data evaluation enables us to combine Ti:Sapphire low-noise performance and high repetition rate in a frequency comb system designed for 24/7 operation. This Optical Frequency Comb is as simple as our well-known FC1500 fiber-based frequency comb systems being workhorses in labs all over the world.