Related Experiment Video
Updated: Jul 4, 2026
09:38
Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
Terahertz sideband-tuned quantum cascade laser radiation.
Andriy A Danylov1, Jerry Waldman, Thomas M Goyette
1Submillimeter-Wave Technology Laboratory, Dept. of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA. Andriy_Danylov@student.uml.edu
Optics Express
|June 11, 2008
Summary
Researchers developed a compact, tunable terahertz source by mixing a quantum cascade laser with microwave frequencies. This novel terahertz source achieved a 2 MHz spectral resolution, enabling precise measurements.
Area of Science:
- Physics
- Spectroscopy
- Quantum Electronics
Background:
- Terahertz (THz) sources are crucial for various scientific applications.
- Developing compact and tunable THz sources remains a significant challenge.
- Quantum cascade lasers (QCLs) offer potential for THz generation but require precise control.
Purpose of the Study:
- To demonstrate a compact and tunable narrowband terahertz source.
- To characterize the spectral properties and bandwidth of the generated THz radiation.
- To evaluate the source's performance using molecular rotational transitions.
Main Methods:
- Mixing a single longitudinal mode 2.408 THz quantum cascade laser with a 2-20 GHz microwave sweeper.
- Utilizing a corner-cube-mounted Schottky diode for frequency mixing.
- Characterizing sideband spectra with a Fourier transform spectrometer.
- Tuning the radiation through D(2)O rotational transitions.
Main Results:
- Successfully generated a compact, tunable, narrowband terahertz source.
- Observed a spectral resolution of 2 MHz in the continuous wave (CW) regime.
- Estimated the longer-term bandwidth of the source by probing D(2)O rotational transitions.
Conclusions:
- The demonstrated method provides a viable approach for creating tunable, narrowband THz sources.
- The source's high spectral resolution and tunability make it suitable for high-precision spectroscopy.
- This technology has potential applications in areas requiring sensitive THz detection and analysis.
