ENGINEERING RADIATIVE TRANSITIONS OF ALKALI-RARE GAS COLLISION PAIRS

Park, Sehyun

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https://hdl.handle.net/2142/107599 Copy

Description

Title

ENGINEERING RADIATIVE TRANSITIONS OF ALKALI-RARE GAS COLLISION PAIRS

Author(s)

Park, Sehyun

Contributor(s)

Eden, J. Gary ; Mironov, Andrey E.

Issue Date

26-Jun-20

Keyword(s)

Lineshapes, collisional effects

Abstract

Optical amplifiers that rely on free-free molecular transition for both pumping and amplification will be introduced. A gaseous medium comprised of Cs vapor and Ar is photoexcited through a free-free molecular transition, B $^{2}$$\Sigma$$_{1/2}^{+}$ $\leftarrow$ X $^{2}$$\Sigma$$_{1/2}^{+}$, with a pulse duration of 8 ns. The gain medium is characterized by scanning the probe wavelength and changing the time delay between the pump and probe pulses. It will be shown that the large bandwidth ($>$150 GHz) and reduced lifetime ($\sim$5 ns) make the amplifiers more suitable for high power IR sources. The optical-to-optical efficiency exceeds 28\% in a single pass amplification. The circular polarization of the optical pump increases the efficiency by 20\%. Furthermore, the weak atomic interaction was identified in the gain spectrum of a Cs-Xe gas mixture by implementing the pump-probe method and compared to the simulation based on the Franck-Condon principle. The spectral feature, also known as the red satellite, had been hard to be resolved experimentally because of the wing structure of A$^{2}$$\Pi$$_{3/2}^{+}$ $\leftarrow$ X $^{2}$$\Sigma$$_{1/2}^{+}$ transition. In the simulation, the Franck-Condon overlap integral develops in the region as the phases of the wavefunctions are stationary to each other, which shows that even a shallow feature in the potential curve can contribute the resulting spectrum significantly. This technique can be utilized in precise atomic spectroscopy.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

English

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http://hdl.handle.net/2142/107599

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