Polarization selection rules in exciton-based terahertz lasers | |
Article | |
关键词: 2-PHOTON ABSORPTION; GREENS-FUNCTIONS; TRANSITIONS; SEMICONDUCTORS; | |
DOI : 10.1103/PhysRevB.88.085321 | |
来源: SCIE |
【 摘 要 】
Optical pumping of excited exciton states in semiconductor quantum wells is a tool for the realization of ultracompact terahertz (THz) lasers based on stimulated optical transition between excited (2p) and ground (1s) exciton states. We show that the probability of two-photon absorption by a 2p exciton is strongly dependent on the polarization of both photons. Variation of the threshold power for THz lasing by a factor of 5 is predicted by switching from linear to circular pumping. We calculate the polarization dependence of the THz emission and identify photon polarization configurations for achieving maximum THz photon generation quantum efficiency.
【 授权许可】
Free