Observation and theoretical simulation of N-resonances in Cs D₂ lines

Abstract

N-type resonances in Cs D2 lines are investigated in optical cell for different detuning of the fixed coupling transition frequency. Using two independent DFB lasers makes it possible to observe high contrast and subnatural-width N-resonances without magnetic field shielding of an optical buffer gas cell with sub-centimeter dimensions. According to the detuning of the coupling laser frequency, an N-resonance with frequency higher or lower than this of the coupling transition frequency is registered. In the first case the N-resonance is in absorption, but in the second case, an inverse N-resonance (enhanced transparency) is measured. A theoretical simulation of the line shape, which is based on solution of optical Bloch equations and considers the interaction of both coupling and probe radiations with the atomic system is done. The simulation leads to N-resonance peaks in agreement with the observed peaks for different positions of the coupling frequency. The presented approach is of importance for further study and optimization of the three-photon and magneto-optical resonances, as well as for miniaturization of optical sensors based on spatially restricted hot alkali vapor.

Coherent magneto-optical resonances on the potassium D2 line in Hanle configuration for magnetometry applications

“…Therefore, the photodetector in this case senses photons absorbed and re-emitted by the atoms in the direction of the photodetector. This corresponds to effective altering to transverse optical geometry, so the signal center is determined by the value of the transverse MF (which is zero in our case) [4][5][6].…”

“…A new approach for development of optical magnetometers, based on the D2 line of K, in Hanle type configuration of crossed laser beam and magnetic field, is reported in [5]. K vapor is irradiated by the light of frequency modulated DFB diode laser (with λ = 766.7nm and 2MHz bandwidth) that results in formation of narrow resonances of reduced absorption (Electromagnetically Induced Transparency (EIT) resonances).…”

Wide range linear magnetometer based on a sub-microsized K vapor cell

“…The narrow-band distributed feedback (DFB) diodelaser described in [34] has a linear frequency scanning range of ∼ 40 GHz. Such type of laser could thus be used for this method of B-field measurement in the range 0.1 − 10 kG.…”

Saturated absorption technique used in Potassium microcell for magnetic field sensing

“…The inaccuracy in the determination of D/d (and therefore B) is caused primarily by the nonlinear scanning of the ECDL lasers over a wide frequency range [22]. The usage of a narrow-band Distributed Feedback (DFB) diode laser as described in [28], which has a linear frequency scanning range of ∼ 40 GHz, would allow one to use this method of B-field measurement in the range 0.1-10 kG.…”