Experimental comparison of silica fibers for laser cooling
Abstract
Laser cooling in silica has recently been demonstrated, but there is still a lack of understanding on how fiber composition, core size, and O H − contamination influence cooling performance. In this work, six Yb-doped silica fibers were studied to illuminate the influence of these parameters. The best fiber cooled by − 70 m K with only 170 mW/m of absorbed pump power at 1040 nm, which corresponds to twice as much heat extracted per unit length compared to the first reported laser cooling in silica. This new fiber has an extremely low O H − loss and a higher Al concentration (2.0 wt.% Al), permitting a high Yb concentration (2.52 wt.% Yb) without incurring significant quenching. Strong correlations were found between the absorptive loss responsible for heating and the loss measured at 1380 nm due to absorption by O H − .
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 14, 2020
- Source ID
- 10.1364/ol.395513
Entities
People
- Jennifer Knall
- John Ballato
- Magnus Engholm
- Michel J. F. Digonnet
- Nanjie Yu
- Peter D. Dragic
Organizations
- Air Force Office of Scientific Research