Phase sensitive amplification enabled by coherent population trapping

• Published in: New journal of physics Vol. 20; no. 8; pp. 83043 - 83051
• Main Authors: Neveu, P, Banerjee, C, Lugani, J, Bretenaker, F, Brion, E, Goldfarb, F
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 30-08-2018; Institute of Physics: Open Access Journals
• Subjects: Amplification; coherent population trapping; Four-wave mixing; phase sensitive amplification; Physics; Polaritons; Quantum Physics; Trapping; two-mode squeezing; two-mode squeezing; coherent population trapping; phase sensitive amplification; four-wave mixing
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/aadb79

We isolate a novel four-wave mixing process, enabled by coherent population trapping (CPT), leading to efficient phase sensitive amplification. This process is permitted by the exploitation of two transitions starting from the same twofold degenerate ground state. One of the transitions is used for CPT, defining bright and dark states from which ultra intense four-wave mixing is obtained via the other transition. This leads to the measurement of a strong phase sensitive gain even for low optical densities and out-of-resonance excitation. The enhancement of four-wave mixing is interpreted in the framework of the dark-state polariton formalism.