A broadband Ytterbium-doped tunable fiber laser for 3He optical pumping at 1083 nm

Abstract

Large amounts of hyperpolarized 3He gas with high nuclear polarization rates are required for use in neutron spin filters or nuclear magnetic resonance imaging of human lung. Very high efficiency can be obtained by metastability exchange optical pumping using multimode lasers to excite the 23S-23P transition at 1083 nm. Broadband Ytterbium-doped tunable fiber lasers have been designed for that particular application. Different options for the architecture of the fiber oscillator are presented and compared. Emphasis is given to a linear cavity configuration that includes a high reflectivity fiber mirror and a low reflectivity tunable fiber Bragg grating. Optical measurements are performed to finely characterize the spectral behavior of the lasers. Atomic response is also quantitatively probed to assess the optimal design of the oscillator for optical pumping. Multimode operation matching the 2 GHz Doppler-broadened helium resonance line and tunability over more than 200 GHz are demonstrated. Boosting the output of this fiber laser with a Yb-doped fiber power amplifier, all-fiber devices are built to provide robust, high power turn-key sources at 1083 nm for improved production of laser polarized 3He.

arXiv commentSubmitted July 2003, published online December 2003 (http://www.springerlink.com). V3 symbols corrected in Figs 10-11; minor final changes included

References in corpus (3)

• In-Vivo NMR of Hyperpolarized Helium-3 in the Human Lung at Very Low Magnetic Fields
• Magnetic Field Effects on the 1083 nm Atomic Line of Helium. Optical Pumping of Helium and Optical Polarisation Measurement in High Magnetic Field
• Spin-resolved off-specular neutron scattering from magnetic domain walls using the polarized ${}^{3}He$ gas spin filter

Cited by in corpus (6)

• Optically Polarized ${}^3$He
• Ultra-sensitive magnetometry based on free precession of nuclear spins
• High nuclear polarization of helium-3 at low and high pressure by metastability exchange optical pumping at 1.5 Tesla
• Temperature-related effects in the polarization of atoms in a magnetized plasma as a promising feature towards high ${}^3$He nuclear polarization
• Polarized Helium to Image the Lung
• High rate production of polarized 3He with meta-stability exchange method