Polarization of ^129Xe with High Power External--Cavity Laser Diode Arrays
Abstract
One important application of laser diode arrays (LDAs) is optical pumping of Rb for spin--exchange polarization of noble gases, which are used in fundamental physics measurements and biomedical imaging. A typical LDA spectrum is comprised of many modes spread over wavelengths of 2 nm or more, while a homogenously broadened Rb absorption line has widths of 0.1-0.2 nm. Despite this apparent mismatch, LDAs are very effective for optical pumping and polarization of noble gases, particularly ^3He. Unfortunately, using LDAs to polarize ^129Xe is less effective. Broadening the Rb absorption line with helium significantly improves Rb polarization; however, practical considerations may limit buffer gas pressure, and high laser powers may introduce heating problems, motivating alternative approaches. We show that narrowing the LDA linewidth can also render LDAs much more effective for ^129Xe polarization. We demonstrate narrowing of LDAs and the impact on ^129Xe polarization.
- Publication:
-
APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- June 2000
- Bibcode:
- 2000APS..DMP..D955Z