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Related Experiment Video

Updated: May 16, 2026

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving

Published on: March 30, 2017

Temperature gradient driven lasing and stimulated cooling.

K Sandner¹, H Ritsch

¹Institute for Theoretical Physics, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.

Physical Review Letters

|December 11, 2012

Summary

This summary is machine-generated.

This study shows lasers can operate using a spatial temperature gradient, not just spectral shaping. This novel approach enables stimulated solid-state cooling and may reduce heating in quantum cascade lasers.

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Area of Science:

Thermodynamics
Quantum Optics
Solid-State Physics

Background:

Lasers function as thermodynamic engines, converting heat to coherent light, ideally near Carnot efficiency.
Conventional lasing relies on spectral shaping to create a higher effective temperature in the pump than the gain transition.

Purpose of the Study:

To investigate if lasing can be achieved using a spatial temperature gradient.
To explore the potential for stimulated solid-state cooling and reduced intrinsic heating in lasers.

Main Methods:

Utilized a toy model of a quantum well structure with two tunnel-coupled wells.
Maintained the coupled wells at different temperatures to establish a spatial temperature gradient.
Analyzed the conditions for gain and narrow-band laser emission based on temperature gradient and resonator quality.

Main Results:

Predicted that lasing can occur with a spatial temperature gradient between pump and gain regions.
Observed that lasing is concurrent with amplified heat flow between thermal reservoirs.
Identified a new mechanism for stimulated solid-state cooling.

Conclusions:

Spatial temperature gradients can drive lasing, offering an alternative to spectral shaping.
This mechanism facilitates stimulated solid-state cooling and could reduce intrinsic heating in quantum cascade lasers.
Potential to enhance the operating regime of quantum cascade lasers by altering injection mechanisms.