Application of coupled resonance processes equation method on of atomic lithium

Liu Yang, Yongyong Zhuang, Yifan Zhang +5 more

In this study, we theoretically proposed a method to achieve an electromagnetically induced transparency (EIT)-like effect in a whispering gallery mode resonator (WGMR) and experimentally validated the method in a lithium niobate (LN) device. Benefitting from the electro-optic and inverse piezoelectric effects of the LN material, two modes of the LN WGMR that are close in frequency can be tuned at different tuning rates, resulting in EIT-like resonance lineshapes. By varying the electric field applied to the LN WGMR, the full dynamic of the EIT-like phenomenon can be precisely controlled. The experimental results agreed well with the calculations based on the coupled mode theory. Moreover, we observed a hysteresis resulting from the photorefractive effect of LN. We believe our proposed method and demonstrated devices offer a way to control an EIT-like effect, which could have potential applications in light storage, quantum information processing, and enhanced sensing techniques.

S.D. Kramer, Jack Phillip Young, G. S. Hurst +1 more

Davorka Azinović, Slobodan Milošević, Goran Pichler

Using the resonance 2s-2p excitation of the Li atom in a lithium-cadmium vapour mixture we observed cadmium atoms excited to very high energy levels such as 6s 3 S 1 , 5d 3 D J and 6p 1 P 1 . As the main excitation process we propose radiative collisions between excited lithium and ground state cadmium atoms followed by an energy-pooling collision between Cd( 3 P J ) atoms. The temporal evolution of intensities of selected lithium and cadmium atomic lines is simulated using a system of rate equations. We estimated the rate coefficient for the radiative collision Li(2p) + Cd(5 1 S 0 ) + h ν 670.8 nm + Δ E →Li(2s) + Cd(5 3 P 0 ), to be 6×10 -10 cm 3 s -1 at T = 965 K.

G. Stephenson

Н. И. Косарев

The method of numerical simulation was used to study the effective deexcitation time of the resonance transition in lithium vapor at the wavelength λ = 670.776 nm. Taking into account the partial frequency redistribution and the cylindrical geometry of the medium, the rate equations of the population balance of a two-level atom were solved along with the equation of radiation transfer. The light scattering by an atom was simulated by a linear combination of the angle-averaged frequency distribution functions R II and R III. The Biberman-Holstein escape factor was calculated as a function of the optical thickness of lithium vapor for different geometries of the luminescing gas and different models of the frequency redistribution functions.

Rong Zhang, Shanti Deemyad