Hot-phonon generation in THz quantum cascade lasers
نویسندگان
چکیده
Observation of non-equilibrium optical phonons population associated with electron transport in THz quantum cascade lasers is reported. The phonon occupation number was measured by using a combination of micro-probe photoluminescence and Stokes/Anti-Stokes Raman spectroscopy. Energy balance analysis allows us to estimate the phonon relaxation rate, that superlinearly increases with the electrical power in the range 1.5 W – 1.95 W, above laser threshold. This observation suggests the occurrence of stimulated emission of optical phonons.
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