A versatile and narrow linewidth infrared radiation source for ro-vibration state-selected preparation of molecules in molecular beams

Avinash Kumar; Saurabh Kumar Singh; Pranav R Shirhatti

doi:10.1063/5.0157912

A versatile and narrow linewidth infrared radiation source for ro-vibration state-selected preparation of molecules in molecular beams

Rev Sci Instrum. 2023 Nov 1;94(11):113001. doi: 10.1063/5.0157912.

Authors

Avinash Kumar¹, Saurabh Kumar Singh¹, Pranav R Shirhatti¹

Affiliation

¹ Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally, Hyderabad 500046, Telangana, India.

PMID: 37947498
DOI: 10.1063/5.0157912

Abstract

We describe the design and characterization of a versatile pulsed (5 ns, 10 Hz repetition rate) optical parametric oscillator and amplifier system capable of generating single longitudinal mode, narrow linewidth (0.01 cm-1) radiations in the wavelength range of 680-870 nm and 1380-4650 nm. Using a combination of power-normalized photoacoustic signal and a Fizeau interferometer-based wavemeter, we are able to actively stabilize the output wavenumber to within 0.005 cm-1 (3σ) over a timescale longer than 1000 s. We demonstrate an application of this system by performing ro-vibration state-selected preparation of CO in the v = 2 state, via direct overtone excitation (v = 0 → 2 at 2346 nm) and subsequent state-selected detection in an internally cold molecular beam.