High Average Power Difference-Frequency Generation in the Mid-Infrared
Abstract
The mid-infrared (mid-IR) region of the electromagnetic spectrum, typically defined as being the 3–8 um wavelength range, is of great interest both scientifically and commercially. It is often referred to as the molecular-fingerprint region due to the large number of organic molecules exhibiting strong absorption in this range, useful for spectroscopic applications including pollution monitoring and breath testing. There is also an atmospheric transmission window from 3–5 um, of paramount importance to applications in remote-sensing/defensive countermeasures, where laser beams are propagated over large distances in the atmosphere to a target. Using lasers in this low loss transmission window for such applications results in more power on the target, leading to higher signal-to-noise ratios in detection and more efficient systems overall. In this proposal, we aim to produce high power mid-IR laser sources for target applications in this region through difference-frequency generation. Our approach has advantages over existing technology in this area as we employ simple, robust and scaleable system architectures. Conventional technologies typically employ resonant cavity structures, which make them technically challenging to implement, often coupled with less stable output powers during long term operation. We instead use single-pass techniques, which are simpler, more economical and present greater power scaling potential. We will generate record level average powers in the continuous-wave and pulsed laser regimes for this spectral region. We will use compact and efficient fiber laser pump sources, the use of which allows mid-IR laser beams to be produced with very high beam quality (a measure of how tightly it is possible to focus the laser beam), vital for the majority of applications. Our proposed research provides an attractive route to lower cost and higher brightness laser sources than is currently possible using existing mid-IR technology.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 02, 2017
- Source ID
- FA95501710194
Entities
People
- Robbie Murray
Organizations
- Air Force Office of Scientific Research
- Imperial College London
- United States Air Force