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Semiconductor Physics Group


Welcome to the Cavendish Terahertz Quantum Cascade Laser research group website. We are based in the Semiconductor Physics research group at the University of Cambridge.

The group's research interests in THz Quantum Cascade Lasers (QCLs) focus on the design, growth, fabrication, and testing of high power THz QCLs emitting across a broad frequency range. All the THz QCL wafers are grown in-house via a state-of-the-art Molecular Beam Epitaxy (MBE) growth centre at the Cavendish Laboratory. The group enjoys strong industrial collabarations with Teraview UK, as well as close working relations with major QCL research groups across Europe.

Our work at Cambridge covers a selection of ambitious projects from ultra-long wavelength emission, phase/mode-locking, multiple colour generation, photonic crystal structures, and naturally, improved laser performance with respect to both maximum temperature operation and peak output power.

Recent publications.


  • Longer wavelength - extending the emission frequencies of THz QCLs to longer wavelengths.
  • Multi colour - designing QCLs that emit at more than one frequency at the same time.
  • Photonic crystal - looking at novel devices that might be produced by interacting a THz QCL with a photonic crystal waveguide.
  • Gain Measurements - direct measurements of the spectral gain in a THz QCL.
  • Distributed feedback (DFB) - applying the distributed feedback technique that has been used successfully in conventional semiconductor lasers to THz QCLs.
  • Mode locking - attempting to mode lock a THz QCL and measuring this with a pulsed terahertz system.