Laser frequency offset-locking using electromagnetically induced transparency spectroscopy of ⁸⁵ Rb in magnetic field

Abstract

We have experimentally offset-locked the frequencies of two lasers using electromagnetically induced transparency (EIT) spectroscopy of 85 Rb vapor with a buffer gas in a magnetic field at room temperature. The magnetic field is generated by a permanent magnet mounted on a translation stage and its field magnitude can be varied by adjusting the distance between the magnet and Rb cell, which maps the laser locking frequency to the space position of the magnet. This frequency-space mapping technique provides an unambiguous daily laser frequency detuning operation with high accuracy. A repeatability of less than 0.5 MHz is achieved with the locking frequency detuned up to 184 MHz when the magnetic field varies from 0 up to 80 G.

High resolution spectroscopy of Rb in magnetic field by far-detuning electromagnetically induced transparency

“…The magnets should be separated far enough to keep the magnetic field homogeneous further through the cell. [31,32] A polarizing beam splitter (PBS) is used to combine the coupling and probe beams in space along the magnetic field. The linear polarization of both beams can be taken as the combination of σ + and σ − since the quantum z axis is defined along the magnetic field.…”

Magnetic splitting of electromagnetically induced transparency and absorption spectra in a standing-wave coupled lambda-type system

“…In the domain of research, EIT has been used to slow light [9] and stop light [10], to achieve lasing without inversion [11], to perform high resolution atomic spectroscopy [12], to perform all optical switching of laser beams [6] and to store pulses of laser light in thermal vapor of atoms [13], etc. On the applications side, EIT has grown to be used in the fields of vector magnetometry [14,15], quantum RF-sensing [16], laser frequency stabilization [17,18], as time standard [19,20] and in many more applications.…”

Electromagnetically induced transparency and electromagnetically induced absorption in Y-type system

“…[31] As a practical application of EIT, Wang et al reported frequency locking of a laser by using the EIT signal obtained in 85 Rb vapor in the presence of magnetic field. [32] Absolute direct frequency measurement of twophoton transition has also been achieved by the multi-peak fitting approach. [33] In this article, we present an analytical study of the fourlevel Y type system based on the density operator method.…”