Watt-level widely tunable single-mode emission by injection-locking of a multimode Fabry-Perot quantum cascade laser
Abstract
Free-running Fabry-Perot lasers normally operate in a single-mode regime until the pumping current is increased beyond the single-mode instability threshold, above which they evolve into a multimode state. As a result of this instability, the single-mode operation of these lasers is typically constrained to few percents of their output power range, this being an undesired limitation in spectroscopy applications. In order to expand the span of single-mode operation, we use an optical injection seed generated by an external-cavity single-mode laser source to force the Fabry-Perot quantum cascade laser into a single-mode state in the high current range, where it would otherwise operate in a multimode regime. Utilizing this approach, we achieve single-mode emission at room temperature with a tuning range of 36 cm−1 and stable continuous-wave output power exceeding 1 W at 4.5 μm. Far-field measurements show that a single transverse mode is emitted up to the highest optical power, indicating that the beam properties of the seeded Fabry-Perot laser remain unchanged as compared to free-running operation.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 05, 2018
- Source ID
- 10.1063/1.5018616
Entities
People
- Alexey Belyanin
- Enrique A. Mejia
- Federico Capasso
- Feng Xie
- Kevin Lascola
- Marco Piccardo
- Paul Chevalier
- Sajant Anand
- Tobias S. Mansuripur
- Yongrui Wang
Organizations
- Harvard University
- National Science Foundation
- Texas A&M University
- University of Texas at Austin
- Wake Forest University