Diode lasers detect terahertz radiation

Oct. 1, 2007
Although great advances have been made in terahertz sources based on Ti:sapphire lasers and in terahertz detectors based on bolometers, these systems are expensive and complex.

Although great advances have been made in terahertz sources based on Ti:sapphire lasers and in terahertz detectors based on bolometers, these systems are expensive and complex. Building on recent research that realized cost-effective terahertz sources and imaging systems by photomixing of diode lasers, researchers at Ruhr-Universität (Bochum, Germany), TU Braunschweig (Braunschweig, Germany), Ferdinand-Braun Institute (Berlin, Germany), and Philipps-Universität (Marburg, Germany) have demonstrated that diode lasers can also be used as terahertz detectors.

To demonstrate terahertz detection, a methanol terahertz laser pumped by a carbon-dioxide laser is coupled into the active region of a diode laser. The diode laser is a single-quantum-well 840 nm laser grown by low-pressure metal-organic vapor-phase epitaxy. Upon terahertz injection, the voltage variations of the p-n junction of the diode laser are measured using a lock-in technique and found to vary as a function of the changing terahertz input. To increase the detection efficiency of this room-temperature detector, antenna structures could be implemented to increase the terahertz-radiation coupling into the laser-diode waveguide, and a diode laser with a weakly doped semi-insulating substrate could be substituted to avoid terahertz power absorption in the highly doped substrate used. Contact Carsten Brenner at [email protected]

Sponsored Recommendations

March 31, 2025
Enhance your remote sensing capabilities with Chroma's precision-engineered optical filters, designed for applications such as environmental monitoring, geospatial mapping, and...
March 31, 2025
Designed for compatibility with a wide range of systems, Chroma's UV filters are engineered to feature high transmission, superior out-of-band blocking, steep edge transitions...
March 31, 2025
Discover strategies to balance component performance and system design, reducing development time and costs while maximizing efficiency.
March 31, 2025
Filter accessories including cubes, sliders, and rings, designed to enhance the performance and versatility of optical systems. These components ensure precise alignment and stability...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!