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Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
Phase seeding of a terahertz quantum cascade laser
Dimitri Oustinov1, Nathan Jukam, Rakchanok Rungsawang
1Laboratoire Pierre Aigrain, Ecole Normale Supérieure, CNRS (UMR 8551), Université P. et M. Curie, Université D. Diderot, 75231 Paris Cedex 05, France.
Nature Communications
|September 16, 2010
Summary
Researchers fixed the random carrier phase in semiconductor lasers using injection seeding. This breakthrough allows for phase-resolved measurements and time-domain spectroscopy with quantum cascade lasers.
Area of Science:
- Optics and Photonics
- Semiconductor Physics
Background:
- Laser action typically starts with random spontaneous emission, leading to an unpredictable carrier phase.
- This random phase prevents phase-resolved detection of laser fields, limiting insights into laser dynamics.
- Quantum cascade lasers (QCLs) are semiconductor lasers with unique properties.
Purpose of the Study:
- To demonstrate a method for fixing the carrier phase in a quantum cascade laser (QCL).
- To enable phase-resolved measurements of laser emission buildup.
- To establish QCLs as sources for time-domain spectroscopy.
Main Methods:
- Injection seeding a QCL with coherent terahertz pulses.
- Synchronous sampling of the emitted laser field with a femtosecond laser beam.
- Time-domain measurement of electric field oscillations.
Main Results:
- Successfully fixed the carrier phase of laser action in a QCL.
- Observed the phase-resolved buildup of the laser field.
- Demonstrated the direct measurement of electric field oscillations in the time domain.
Conclusions:
- Injection seeding provides control over the carrier phase in QCLs.
- Phase-resolved measurements offer new insights into laser dynamics.
- QCLs can now serve as versatile sources for time-domain spectroscopy.
