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Ashwini Vaishnav

Publications and source records attributed to Ashwini Vaishnav.

2 recordsLinked to original sources

Non-resonant laser-driven narrowing of particle velocity distributions

Stark acceleration and deceleration based techniques for generating particle ensembles with low velocity spread are useful in many experimental applications. For a given velocity distribution of a particle ensemble, these techniques accelerate or decelerate a small subset of the total population, with a low velocity uncertainty. However, narrowing the original velocity distribution by accelerating or decelerating the ensemble particles near the mean velocity is fundamentally limited and not yet explored. We present a numerical study of particle dynamics using neutral cesium atoms as an example. We investigate different interaction regimes, identify key limitations, and propose an interaction regime in which optical Stark deceleration can be used to narrow the velocity distribution of a propagating ensemble about its mean velocity. These findings have potential implications for optical manipulation and control, controlled collisions, and matter interferometry.

physics.optics

High-energy chirped nanosecond pulsed laser system for particle diagnostics and manipulation

An upgraded high-energy nanosecond pulsed laser system tailored for optical particle diagnostics and manipulation capable of pulse energies beyond Joule-level is presented. In addition to the notable output energy increase, the laser system maintains its capability to generate laser pulses with customizable temporal profiles and variable durations ($1$ ns to $1$ $μ$s) along with a chirping range of several GHz over the pulse duration. The expanded output energy range is anticipated to greatly broaden the laser system's application potential, both for thermodynamic diagnostics via coherent Rayleigh-Brillouin scattering, by substantially lowering the particle density detection thresholds, as well as for particle manipulation, by facilitating more efficient optical trapping potentials for particle acceleration and deceleration.

physics.optics