Superradiance in IR and optical transitions of molecules

V. M. Kaslin, O. F. Yakushev

Laser superradiance was achieved for the first time as a result of an electronic transition in a diatomic heteronuclear molecule as a result of direct optical pumping. This superradiance was observed in the region of 670 nm due to a transition to the ground stated X 1Σ + of the intermetallic alkali molecule NaRb pumped by radiation from a pulsed copper vapor laser (λ =510.6 nm).

I.M. Lizin, Махвиладзе Тариэль Михайлович, Leonid A. Shelepin

Susumu Kuma, Takamasa Momose

We propose a new method for making ultracold molecules below 300 μK by cooling via the dipole force of an intense infrared (IR) standing wave created in a high finesse cavity. Deceleration can be achieved by periodically switching an IR standing wave slightly red-detuned from the resonance frequency of a molecular vibration–rotation transition. The potential depth becomes as high as 50 mK with an incident laser power of 3 W. By properly switching the potential, one can remove the translational energy of molecules from a couple of hundred mK to 300 μK or below. Since all molecules except homonuclear diatomic molecules have one or more optical transitions in the IR range that can be used for a source of the dipole force, the present method is applicable to almost all molecules of chemical interest. Moreover, by choosing an appropriate rotation–vibration transition, one can decelerate and trap molecules in the completely ground state in any degrees of freedom. Numerical simulations showed sufficiently wide phase-space areas of decelerated molecules through use of this technique for practical applications. The effect of various parameters on the efficiency of the cavity decelerator has been examined by numerical simulations.

P. V. Zinov’ev, Nataliya B. Silaeva, Yu. E. Sheǐbut

Gennady G. Matvienko, В. Е. Прокопьев, Viktor K. Oshlakov +1 more

Theoretical and experimental study of nonresonance generation of laser radiation by atoms, molecules and ions of matter - superradiation - is an important area of research in the field of femtosecond optics. Narrowly directed (forward and reverse), with an intensity proportional to the square of the number of inverted atoms, molecules and ions, radiation can be used to probe the atmosphere using femtosecond lidars. This paper presents the results of comparative experimental studies of the appearance of superradiance at transitions of molecular nitrogen ion in the atmosphere and at transitions of atomic strontium ion in a mixture with inert gases (He, Ne) in a heated cuvette. For the first time, superradiance was observed in the transition from the resonant electronic state 2Р1/2 / to the ground state 2S1/2 (407.8 nm), when Sr pairs were pumped by radiation at a wavelength of 268.1 nm.

V.M. Agranovich, Shaul Mukamel