Evaporative cooling by pulse width modulation (PWM) of optical dipole traps

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Maurya, S. Sagar, Sunil, Joel M., Bhartiya, Monu, Dutta, Pranab, Mangaonkar, Jay, Sawant, Rahul, Rapol, Umakant D.
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866908600939577344
author Maurya, S. Sagar
Sunil, Joel M.
Bhartiya, Monu
Dutta, Pranab
Mangaonkar, Jay
Sawant, Rahul
Rapol, Umakant D.
author_facet Maurya, S. Sagar
Sunil, Joel M.
Bhartiya, Monu
Dutta, Pranab
Mangaonkar, Jay
Sawant, Rahul
Rapol, Umakant D.
contents We introduce a method for cooling atoms in an optical dipole trap using pulse-width modulation (PWM) technique, without reducing the laser power of the dipole trap. The PWM technique involves digital modulation of the trap at a fixed frequency. The effective time-averaged dipole potential is lowered by adjusting the duty cycle of the modulation, thereby implementing evaporative cooling. We show that, this technique effectively reduces temperature and enhances phase space density. A comparison with the standard method of evaporative cooling has also been made. Apart from the atom loss due to reduction of the effective trapping potential, we observe an additional loss channel originating from the lack of trapping potential during the trap off time. This atom loss is observed at different modulation frequencies which are an order of magnitude higher compared to trapping frequency of dipole trap. The PWM technique provides an alternative to traditional evaporative cooling in scenarios where it is preferred that the laser power of the trap should be constant.
format Preprint
id arxiv_https___arxiv_org_abs_2501_16503
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Evaporative cooling by pulse width modulation (PWM) of optical dipole traps
Maurya, S. Sagar
Sunil, Joel M.
Bhartiya, Monu
Dutta, Pranab
Mangaonkar, Jay
Sawant, Rahul
Rapol, Umakant D.
Atomic Physics
We introduce a method for cooling atoms in an optical dipole trap using pulse-width modulation (PWM) technique, without reducing the laser power of the dipole trap. The PWM technique involves digital modulation of the trap at a fixed frequency. The effective time-averaged dipole potential is lowered by adjusting the duty cycle of the modulation, thereby implementing evaporative cooling. We show that, this technique effectively reduces temperature and enhances phase space density. A comparison with the standard method of evaporative cooling has also been made. Apart from the atom loss due to reduction of the effective trapping potential, we observe an additional loss channel originating from the lack of trapping potential during the trap off time. This atom loss is observed at different modulation frequencies which are an order of magnitude higher compared to trapping frequency of dipole trap. The PWM technique provides an alternative to traditional evaporative cooling in scenarios where it is preferred that the laser power of the trap should be constant.
title Evaporative cooling by pulse width modulation (PWM) of optical dipole traps
topic Atomic Physics
url https://arxiv.org/abs/2501.16503