12.5-GHz-spaced laser frequency comb covering over 100 THz and frequency shift of all individual lines for calibration of infrared Doppler instrument

We demonstrate the direct generation of a laser frequency comb whose spectrum spanning over 100 THz with a 12.5-GHz spacing. It is confirmed that individual lines on the comb spectrum are shifted around 40 MHz in parallel, which could be useful for spectrograph calibration.