Tuning fork at room temperature detects terahertz radiation

Sept. 1, 2009
Researchers at the Clausthal University of Technology (Goslar, Germany), the Laboratorio NEST (Pisa, Italy), and the University of Cambridge (Cambridge, England) have created a simple detector for terahertz radiation that works at room temperature.

Researchers at the Clausthal University of Technology (Goslar, Germany), the Laboratorio NEST (Pisa, Italy), and the University of Cambridge (Cambridge, England) have created a simple detector for terahertz radiation that works at room temperature. The device is built around a miniature quartz tuning fork from a standard wristwatch; radiation modulated at the tuning fork’s natural frequency of 32,670 Hz causes the tuning fork to vibrate as a result of radiation pressure (“photon momentum”). The vibration of the tuning fork is sensed by detecting the piezoelectric current produced by the tuning fork as it vibrates.

The detector was tested using a quantum-cascade laser (QCL) as the terahertz source, which emitted on the order of 0.5 mW of 2.8 THz radiation. Because there was some crosstalk between the electronics and the tuning fork, the true reading of the detector was considered to be the measured reading minus a reading taken with all radiation blocked. The photon-momentum detector was tested against a silicon bolometer and a Golay cell, and found to have an approximately linear response over a range of about a factor of five. The detector was also used to capture scanned images. The researchers believe its best use may be as a “monitor photodiode” type detector for a QCL. Contact Ulrike Willer 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
Explore the essential role of optical filters in enhancing Raman spectroscopy measurements including the various filter types and their applications in improving signal-to-noise...

Voice your opinion!

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