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Room temperature continuous wave, monolithic tunable THz sources based on highly efficient mid-infrared quantum
Quanyong Lu1, Donghai Wu1, Saumya Sengupta1
1Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL 60208, USA.
Scientific Reports
|March 25, 2016
Summary
Researchers developed a novel quantum cascade laser for efficient terahertz (THz) generation. This compact THz source operates continuously at room temperature, enabling advanced applications in sensing and imaging.
Area of Science:
- Semiconductor Physics
- Optoelectronics
- Quantum Engineering
Background:
- Terahertz (THz) sources are crucial for spectroscopy, communication, sensing, and imaging.
- Compact, high-power, room-temperature continuous-wave (CW) THz sources are needed for system development.
Purpose of the Study:
- To present a novel quantum cascade laser (QCL) design for efficient THz generation.
- To demonstrate room-temperature CW THz emission with improved efficiency and tunability.
Main Methods:
- Utilized a strong-coupled strain-balanced quantum cascade laser design.
- Employed intracavity difference frequency generation for THz production.
- Fabricated monolithic three-section sampled grating distributed feedback-distributed Bragg reflector (SG-DBR) lasers.
Main Results:
- Achieved room-temperature CW THz emission at 3.41 THz with 30 dB side-mode suppression and 14 μW output power.
- Demonstrated a wall-plug efficiency approximately one order of magnitude higher than previous devices.
- Showcased CW, single-mode THz emissions with a wide tuning range (2.06–4.35 THz) and up to 4.2 μW output power.
Conclusions:
- The presented QCL design offers a highly efficient pathway for THz generation.
- This advancement facilitates the development of compact, room-temperature THz systems for diverse applications.
- The demonstrated wide frequency tuning range and improved efficiency represent significant progress in THz technology.
