Office of Technology Transfer – University of Michigan

Real-time Terahertz Detection & Imaging using Photoacoustic Conversion

Technology #5854

Researchers at the University of Michigan have developed a technology for the real-time detection and imaging of terahertz (THz) pulse radiation by using photoacoustic conversion. Terahertz sensing often finds applications in industry, biology, and material science. Most existing techniques for terahertz sensing require bulky optics or need cryogenic cooling. Further, applications requiring fast, real-time, detection are limited by long detector integration times (1-1000 milliseconds).

Design Details

The terahertz sensing technology developed at the University of Michigan utilizes the photoacoustic effect by converting terahertz radiation into sound. The sensing mechanism overcomes the challenges seen with traditional designs, such as nanobolometers, Golay cells, and pyroelectric detectors, and offers advantages such as room temperature operation, fast response time, small footprint, and high sensitivity. An efficient transducer converts terahertz pulse energy into ultrasound, for example, by using a carbon nanotube-polymer composite. The converted ultrasonic waves can be detected by a highly sensitive acoustic sensor such as an optical microring resonator.


  • Terahertz imaging
  • Chemical identification
  • Characterization of electronic and vibrational properties of materials


  • Room temperature operation for easy and low-cost operation
  • Fast response times (order of microseconds)
  • Small size and on-chip design for easy integration
  • High sensitivity