Increase of NMR/MIR signals under ultra-low B fields with hyperpolarized Xe using 1W CW single-frequency Ti:Sapphire laser

In recent years, hyperpolarized noble gas MRI attracts attention. Spin-exchange optical pumping (SEOP) is often used for hyperpolarizing nuclear spin of noble gas. Although there are many reports on rare gas hyperpolarization devices using SEOP, most of them use high power CW lasers exceeding 10 W. Large output laser has high risk of exposure, high cost and high energy consumption. However, in SEOP, only a very small amount coincident with D1 line works and almost all other power is abandoned. Therefore, in this study, we development that Xe hyperpolarizing system using narrow linewidth Ti:Sapphire laser and demonstrated that this system can pump with lower pawer by tuning wavelength to D1 line. As a result, we show that system using narrow linewidth laser can get equally or lager signal augment ratio by 1/45 times lower irradiation power than conventional system.