INFRARED (4-11 MU-M) QUANTUM CASCADE LASERS

摘要

This paper reviews the state-of-the-art of quantum cascade lasers. Quantum cascade lasers are new unipolar light sources based on electron resonant tunneling and optical transitions between quantized conduction band states. Quantum engineering of the electronic energy levels, wavefunctions, matrix elements and scattering rates is used to design population inversion and optimize laser gain and overall performance. The laser wavelength can be selected over a broad range (4-12 mu m) of the infrared spectrum using the same heterostructure material by tailoring the active layer thickness. Using MBE grown AlInAs/GaInAs heterostructures, room temperature operation at 5 mu m and 8.5 mu m has been achieved and the operating wavelength has been extended to 11 mu m. (C) 1997 Elsevier Science Ltd. References: 13