Abstract
In order to discover Earth-like exoplanets, we need a Doppler shift detection capability with high
accuracy of 0.7 MHz in the near-infrared region. A broadband laser frequency comb (LFC) has been
greatly expected as ideal standards for the calibration of astronomical spectrographs. The requirements
for the LFC are broad bandwidth, high frequency stability and multi-gigahertz spacing spectrally
resolvable by the spectrographs. In order for the Subaru telescope to challenge the Earth-like exoplanet
detection, we have developed the LFC generator consisting of an optical pulse synthesizer, an optical
pulse compressor and a highly nonlinear fiber. The two stage amplification having band-pass filters and
a Fabry-Perot filter realized high power pump pulses with low noise. We successfully generated the
12.5-GHz-spacing laser frequency comb ranging over 600 nm from 1070 to 1700 nm.
