Abstract-Dual-comb spectroscopy of water vapor with a free-running semiconductor disk laser

1. S. M. Link1,*, 
2. D. J. H. C. Maas2, 
3. D. Waldburger1, 
4. U. Keller1

1. 1Department of Physics, Institute for Quantum Electronics, ETH-Zürich, 8093 Zürich, Switzerland.
2. 2ABB Switzerland, Corporate Research, Segelhofstrasse 1K, 5405 Baden-Daettwil, Switzerland.

1. ↵*Corresponding author. Email: slink@phys.ethz.ch
2. 
   

http://science.sciencemag.org/content/early/2017/05/10/science.aam7424

Dual-comb spectroscopy offers the potential for high accuracy combined with fast data acquisition. Applications are often limited, however, by the complexity of optical comb systems. Here we present dual-comb spectroscopy of water vapor using a substantially simplified single-laser system. Very good spectroscopy measurements with fast sampling rates are achieved with a free-running dual-comb mode-locked semiconductor disk laser. The absolute stability of the optical comb modes is characterized both for free-running operation and with simple microwave stabilization. This approach drastically reduces the complexity for dual-comb spectroscopy. Bandgap engineering to tune the center wavelength from the UV to the mid-IR could optimize frequency combs for specific gas targets, further enabling dual-comb spectroscopy for a wider range of industrial applications.