Polarization spectroscopy in (4)He around 1083 nm is observed and optimized with a distributed feedback fiber laser and is applied for frequency stabilization. In order to improve the accuracy and long-term stability of the frequency-locking performance, a power stabilization module is added, and the dependences of the peak-to-peak amplitude and frequency difference (width) of the polarization spectroscopy signal on various pump and probe powers are investigated.

No abstract

No abstract

Abstract

We study the dressed states of 3 He atoms and experimentally observe the Mollow triplet (MT) induced with an ultra-low-frequency (ULF) oscillating magnetic field as low as 4 Hz. The ULF-MT signatures from the ground states of 3 He atoms are transferred to the metastable states by metastability-exchange collisions (MECs) and measured optically, which demonstrates 2 s coherence time in the dressed ground states. The result shows the possibility of ULF magnetic field amplitude measurement and a new scheme for optical frequency modulation.