Tunable optical delay via carrier induced exciton dephasing in semiconductor quantum wells.
نویسندگان
چکیده
We report the experimental realization of a tunable optical delay by exploiting unique incoherent nonlinear optical processes in semiconductors. The tunable optical delay takes advantage of the strong Coulomb interactions between excitons and free carriers and uses optical injection of free carriers to broaden and bleach an exciton absorption resonance. Fractional delay exceeding 200% has been obtained for an 8 ps optical pulse propagating near the heavy-hole excitonic transition in a GaAs quantum well structure. Tunable optical delay based on optical injection of free carriers avoids strong absorption of the pump beam and is also robust against variations in the frequency of the pump beam.
منابع مشابه
TUNABLE ALL-OPTICAL DELAY VIA NONLINEAR OPTICAL PROCESSES IN SEMICONDUCTOR QUANTUM WELLS by SUSANTA
The dramatic experimental demonstration of slow light in atomic vapors via electromagnetically induced transparency (EIT) has stimulated considerable interest in the dynamic control of the group velocity of light and in the development of tunable all-optical delays. This dissertation presents experimental studies of all-optical tunable delays via nonlinear optical processes in semiconductor qua...
متن کاملPhonon-Induced Dephasing of Optically Driven Exciton States in Quantum Dots: Spectral Interpretation
In recent years it has become possible to control the charge state of a single quantum dot (QD) far beyond the linear absorption regime. A convincing example of this experimental progress are pulse area-dependent Rabi oscillations of the exciton occupation, i.e., coherent transitions from the ground crystal state to the singleor bi-exciton state and back, driven by optical pulses of variable in...
متن کاملLarge optical gain from four-wave mixing instabilities in semicon- ductor quantum wells
Based on a microscopic many-particle theory, we predict large optical gain in the probe and background-free four-wave mixing directions caused by excitonic instabilities in semiconductor quantum wells. For a single quantum well with radiative-decay limited dephasing in a typical pump-probe setup we discuss the microscopic driving mechanisms and polarization and frequency dependence of these ins...
متن کاملTRION-BASED OPTICAL PROCESSES IN SEMICONDUCTOR QUANTUM WELLS by THOMAS KENDRICK BALDWIN A DISSERTATION
Original approval signatures are on file with the University of Oregon Graduate School. In a semiconductor, negative charge is carried by conduction-band electrons and positive charge is carried by valence-band holes. While charge transport properties can be understood by considering the motion of these carriers individually, the optical properties are largely determined by their mutual interac...
متن کاملMemory and correlation effects in the exciton-phonon kinetics
The interaction between excitonic and phonon modes in semiconductor nanostructures leads to both relaxation of the excitonic population as well as to pure dephasing of the optical polarization. In small quantum dots, where the interstate relaxation is tiny, clear signatures of pure dephasing effects have been measured, see e.g. the extensive work done in [1] and [2]. In this case, an accurate t...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Optics express
دوره 14 7 شماره
صفحات -
تاریخ انتشار 2006