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Terahertz two-photon quantum well infrared photodetector
H Schneider1, H C Liu, S Winnerl
1Forschungszentrum Dresden Rossendorf, Institute of Ion Beam Physics and Materials Research, P O Box 510119, D-01314 Dresden, Germany. h.schneider@fzd.de
Optics Express
|August 6, 2009
Summary
We developed a sensitive two-photon detector using GaAs/AlGaAs quantum wells for Terahertz (THz) applications. This detector achieves quadratic detection at picosecond pulse energies, enabling new possibilities in THz spectroscopy.
Area of Science:
- Optics and Photonics
- Semiconductor Physics
- Quantum Wells
Background:
- Intersubband transitions in quantum wells offer unique optical properties.
- Terahertz (THz) detection requires sensitive methods for low-energy photons.
- Optical nonlinearities can enhance detector sensitivity.
Purpose of the Study:
- To report a novel two-photon detector operating in the THz regime.
- To leverage resonant optical nonlinearities for sensitive quadratic detection.
- To demonstrate the detector's application in THz pulse characterization.
Main Methods:
- Fabrication of GaAs/AlGaAs quantum wells.
- Utilizing intersubband transitions below the Reststrahlenband.
- Implementing quadratic detection schemes for enhanced sensitivity.
- Developing a quadratic autocorrelator setup.
Main Results:
- Achieved sensitive quadratic detection at picosecond pulse energies (pJ).
- Demonstrated detector operation in the Terahertz regime (around 7 THz).
- Successfully used the detector in a quadratic autocorrelator.
Conclusions:
- The developed two-photon detector offers high sensitivity for THz applications.
- Resonantly enhanced nonlinearities are crucial for sensitive quadratic detection.
- This technology enables advanced characterization of far-infrared picosecond pulses.
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