Versatile silicon-waveguide supercontinuum for coherent mid-infrared spectroscopy
Abstract
Laser frequency combs, with their unique combination of precisely defined spectral lines and broad bandwidth, are a powerful tool for basic and applied spectroscopy. Here, we report offset-free, mid-infrared frequency combs and dual-comb spectroscopy through supercontinuum generation in silicon-on-sapphire waveguides. We leverage robust fabrication and geometrical dispersion engineering of nanophotonic waveguides for multi-band, coherent frequency combs spanning 70 THz in the mid-infrared (2.5 μm–6.2 μm). Precise waveguide fabrication provides significant spectral broadening with engineered spectra targeted at specific mid-infrared bands. We characterize the relative-intensity-noise of different bands and show that the measured levels do not pose any limitation for spectroscopy applications. Additionally, we use the fabricated photonic devices to demonstrate dual-comb spectroscopy of a carbonyl sulfide gas sample at 5 μm. This work forms the technological basis for applications such as point sensors for fundamental spectroscopy, atmospheric chemistry, trace and hazardous gas detection, and biological microscopy.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 01, 2018
- Source ID
- 10.1063/1.5006914
Entities
People
- Abijith S. Kowligy
- Connor Fredrick
- Daniel L. Maser
- Daron Westly
- Flavio C Cruz
- Henry Timmers
- Jeff Chiles
- Jeffrey M. Shainline
- Nima Nader
- Richard P Mirin
- Sae Woo Nam
- Scott A. Diddams
Organizations
- National Institute of Standards and Technology
- University of Colorado Boulder