ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
An experimental and theoretical comparative analysis of the output characteristics of λ ≈9[removed info]m GaAs/Al0.45Ga0.55As quantum cascade lasers based on single and double phonon resonancedepopulation mechanisms were presented. The layer structures were grown with solid sourcemolecular beam epitaxy and consist of 48 or 36 active stages embedded in a symmetrical plasmonenhanced waveguide. From the wafers, ridge waveguide lasers were fabricated by opticallithography and dry etching. The theoretical model is based on a fully non-equilibrium Schrödinger-Poisson self-consistent analysis of the coupled scattering rate and single-temperature energybalance equations, taking all relevant electron-LO phonon, electron-electron and electron-ionisedimpurity scattering processes into account. Single phonon resonance devices exhibit clear currentsaturation, simultaneously with a decrease of the optical power. In the moderate doping regime, aquasi-linear dependence of both the threshold and saturation current densities on injector doping,were measured, in a very good agreement with theoretical predictions. Double phonon resonancelasers exhibit ‘saturation’ mechanism evident from their decrease in optical power, but withoutpronounced current saturation. Previously reported saturation of the ‘maximal’ current under higherinjector doping in single phonon resonance lasers, is also observed in the double phonon resonancestructure for injector sheet doping above 8x1011cm-2
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.518.29.pdf
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