Office of Technology Transfer – University of Michigan

Reconfigurable Mesh Filters for Broadband Terahertz/Infrared Wave Modulation

Technology #5731

A research team at the University of Michigan has developed a terahertz (THz) modulator that exhibits broadband, high amplitude modulation index. The use of THz technologies in many industries including semiconductor metrology, food quality processing, homeland security, medical imaging and communications, has led to staggering growth in the field in the last decade. Efficient light sources and detectors have seen commercialization; however signal modulation, which is imperative for response discrimination and THz communications, has not been as thoroughly investigated due to a lack of naturally occurring materials with required dielectric properties and fabrication constraints prohibiting the use of conventional form factors such as Fabry-Perot interferometers. These difficulties have led to low modulation indices, or little discrimination between the “on” and “off” states of the modulator. The research team’s technology has potential to curb this trend with its high modulation index, broadband operation, competitive operating voltages and desirable modulation speed.

Broadband THz modulator with a high modulation index

Their THz modulator has been computationally designed and optimized, and has experimentally demonstrated greater than 67% modulation index across a 1.5 THz band. Using an efficient actuation means, it can be driven at modulation speeds greater than 20 kHz, at desirable 30 V biasing. Coupling these benefits with conventional CMOS fabrication requirements provides this modulation platform with the foundation to enable next generation THz technologies with superior response discrimination and communications capabilities, desirable for many industries.


  • Spectroscopy-Chemical and biological sensing
  • Materials Characterization
  • Communications
  • Food quality assurance
  • Semiconductor metrology
  • Homeland security
  • Pharmaceutical manufacturing


  • Greater than 67% modulation index
  • Broadband-1.5 THz
  • High operating frequency-20 kHz
  • Conventional CMOS fabrication