Vertical subwavelength mode confinement in terahertz and mid-infrared quantum cascade lasers

• DOI: 10.1063/1.3560980
• Publication Date: 2011-03-08T00:33:20Z
• Authors: E. Strupiechonski; D. Grassani; D. Fowler; F. H. Julien; S. P. Khanna; L. Li; E. H. Linfield; A. G. Davies; A. B. Krysa; R. Colombelli
• Keywords: Photomixing; Quantum cascade laser

We exploit the modal confinement properties of metal-metal ridge waveguides to investigate effect reducing thickness active laser cores in both terahertz and mid-infrared quantum cascade lasers. Devices with regions over 55 times thinner than free-space emission wavelength are demonstrated. They show only a modest increase threshold current density compared conventional-thickness devices. The limited is possibly due parasitic channel addition radiative channel. These structures could be useful for development ultra-low volume