Open AccessTwo-photon photocurrent autocorrelation using intersubband transitions at nearly-resonant excitation
Author(s) -
Harald Schneider,
Thomas Maier,
H.C. Liu,
M. Walther
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.001523
Subject(s) - physics , excitation , autocorrelation , resonance (particle physics) , two photon excitation microscopy , photon , photocurrent , atomic physics , optics , nonlinear optics , intermediate state , laser , quantum mechanics , statistics , mathematics
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.