Two-photon photocurrent autocorrelation using intersubband transitions at nearly-resonant excitation.
We investigate nonlinear mid-infrared detection via two-photon transitions involving two bound subbands and one continuum resonance in an n-type multiple quantum well. By varying the excitation energy, we have tuned the two-photon transition from resonant, yielding optimum resonant enhancement with a real intermediate state, to nearly-resonant, with a virtual but resonantly enhanced intermediate state. For autocorrelation purposes, the latter configuration improves time resolution whilst partially retaining a resonant enhancement of the two-photon transition strength.
Schneider
Harald
H
Forschungszentrum Dresden Rossendorf, Institute of Ion Beam Physics and Materials Research, P. O. Box 510119, D-01314 Dresden, Germany. h.schneider@fzd.de
Maier
Thomas
T
Liu
H C
HC
Walther
Martin
M
D004867:Equipment Design; D019544:Equipment Failure Analysis; D007259:Infrared Rays; D008872:Microwaves; D055095:Optics and Photonics / Q000295:instrumentation*; D017785:Photons; D013057:Spectrum Analysis / Q000295:instrumentation*; D013223:Statistics as Topic; D014159:Transducers