Science Daily April 27, 2018
A team of researchers in the US (Lehigh University, Sandia National Laboratory) demonstrated a new hybrid grating scheme that uses a superposition of second and fourth-order Bragg gratings that excite a symmetric mode with much greater radiative efficiency. The scheme is implemented for terahertz QCLs with metallic waveguides. Peak power output was 170 mW. The hybrid grating scheme is simpler to implement than distributed feedback (DFB) schemes and could be used to increase power output for surface-emitting DFB lasers at any wavelength… read more. Open Access TECHNICAL ARTICLEÂ
A scanning electron microscope image of a high-power surface-emitting terahertz semiconductor laser with hybrid gratings. Credit: Sushil Kumar, Lehigh University