Abstract
We study the frequency noise and the referencing to a near-infrared frequency comb of a widely tunable external-cavity quantum-cascade-laser that shows a relatively narrow free-running emission linewidth of 1.7 MHz. The frequency locking of the laser to the comb further narrows its linewidth to 690 kHz and enables sub-Doppler spectroscopy on an N2O transition of the ν1 band near 7.7 μm with sub-MHz resolution and absolute frequency calibration. The combined uncertainty on the measured transition center is estimated to be less than 50 kHz
Original language | English (US) |
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Pages (from-to) | 23785 |
Journal | Optics Express |
Volume | 27 |
Issue number | 17 |
DOIs | |
State | Published - Aug 5 2019 |