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IQSE AMO/QO Seminar Series


"Control of quantum interference between two-photon and three-photon absorption processes in semiconductors"


Dr. Kai Wang
University of Michigan

ABSTRACT 

When different quantum evolution pathways can lead a system from an initial to a final state, quantum interference between the routes leads to enhancement or suppression of the transition rate. Quantum interference control (QuIC) based on optical processes with different photon number has been used for exciting target states in both molecular and crystalline systems. We report the first experiments demonstrating Quantum Interference Control (QuIC) based on two nonlinear optical absorption processes in semiconductors. We use two optical beams of frequencies ω and 3ω/2 incident on AlGaAs, and measure the injection current due to the interference between 2- and 3-photon absorption processes. We analyze the dependence of the QuIC current on the intensities, phases, and polarizations of the incident fields. Using this QuIC photocurrent, the carrier-offset frequency of a fiber laser frequency comb was measured. This scheme is promising since the bandwidth required is reduced, and waveguide detection in integrated structures should lead to more compact devices for comb offset frequency measurements.


Tuesday, December 5, 2017
IQSE Seminar Room, 12:00 Noon
(578 MPHY)


Institute for Quantum Science and Engineering
Texas A&M University

(Pizza and salad to be served at 11:30 am)