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Demonstration of a room temperature 2.48-2.75 THz coherent spectroscopy source
John C Pearson1, Brian J Drouin, Alain Maestrini
1Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena California 91109, USA. John.C.Pearson@jpl.nasa.gov
The Review of Scientific Instruments
|October 7, 2011
Summary
A new electronic solid-state terahertz (THz) source offers a continuous wave coherent signal for spectroscopy. This breakthrough enables high-resolution measurements of molecules like water and methanol.
Area of Science:
- Physics
- Spectroscopy
- Terahertz (THz) technology
Background:
- Terahertz (THz) electromagnetic spectrum historically relied on lasers for coherent sources.
- Solid-state electronic sources were previously limited in power and bandwidth for THz generation.
Purpose of the Study:
- To demonstrate a novel, purely electronic, solid-state continuous wave coherent THz source.
- To enable high-resolution spectroscopic measurements in the THz region.
Main Methods:
- Utilized a 91.8-101.8 GHz synthesizer, power amplifier, and three cascaded frequency triplers.
- Developed a spectrometer achieving sub-Doppler frequency resolution.
Main Results:
- Achieved a continuous wave coherent source covering 2.48-2.75 THz with >10% tuning bandwidth and 1-14 μW output power at room temperature.
- Demonstrated unprecedented resolution and signal-to-noise ratio in spectroscopic measurements of water, methanol, and carbon monoxide.
- Observed the Lamb-dip effect in water, indicating high power and beam quality.
Conclusions:
- This electronic solid-state source provides a viable alternative to lasers for THz applications.
- The source's capabilities open new avenues for molecular physics research and precision metrology.
- Potential applications include absorption spectroscopy, heterodyne systems, and controlling other THz sources.
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