Related Experiment Videos
Phase coherent photorefractivity in ZnSe single quantum wells
H P Wagner1, S Tripathy, H-P Tranitz
1Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221-0011, USA.
Physical Review Letters
|May 21, 2005
Summary
We observed an efficient photorefractive effect in zinc selenide (ZnSe) quantum wells using ultrashort light pulses. This effect, driven by coherent excitons, creates an electron grating, preserving light
Area of Science:
- Solid-state physics
- Quantum optics
- Materials science
Background:
- Photorefractive effects are crucial for optical signal processing.
- Quantum wells offer unique optoelectronic properties.
- Excitonic transitions are fundamental to semiconductor optics.
Purpose of the Study:
- To investigate the phase coherent photorefractive effect in ZnSe single quantum wells.
- To understand the role of excitonic transitions in this effect.
- To analyze the underlying mechanisms using theoretical models.
Main Methods:
- Utilizing ultrashort light pulses resonant to excitonic transitions.
- Observing the photorefractive effect in ZnSe single quantum wells.
- Performing numerical calculations based on optical Bloch equations for a three-level system.
Main Results:
- An efficient phase coherent photorefractive effect was observed.
- The effect is attributed to electron grating formation induced by coherent excitons.
- Numerical calculations accurately reproduced the diffracted signal's features.
Conclusions:
- Coherent excitons in ZnSe quantum wells can induce a phase coherent photorefractive effect.
- The interplay between excitons and light fields is key to this phenomenon.
- Optical Bloch equations provide a valid framework for describing such coherent effects.