Abstract-Cascaded interactions mediated by terahertz radiation

M. Hemmer, G. Cirmi, K. Ravi, F. Reichert, F. Ahr, L. Zapata, O. D. Mücke, A.-L. Calendron, H. Çankaya, D. Schimpf, N. H. Matlis, and F. X. Kärtner

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-10-12536

We investigate a regime of parametric amplification in which the pump and signal waves are spectrally separated by only a few hundreds of GHz frequency – therefore resulting in a sub-THz frequency idler wave. Operating in this regime we find an optical parametric amplifier (OPA) behavior which is highly dissimilar to conventional OPAs. In this regime, we observe multiple three-wave mixing processes occurring simultaneously which results in spectral cascading around the pump and signal wave. Via numerical simulations, we elucidate the processes at work and show that cascaded optical parametric amplification offers a pathway toward THz-wave generation beyond the Manly-Rowe limit and toward the generation of high-energy, sparse frequency-combs.

Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Abstract-Parametric Amplification of a Terahertz Quantum Plasma Wave

Authors: Srivats Rajasekaran, Eliza Casandruc, Yannis Laplace, Daniele Nicoletti, Genda D. Gu,Stephen R. Clark, Dieter Jaksch, Andrea Cavalleri

http://www.mathpubs.com/detail/1511.08378v1/Parametric-Amplification-of-a-Terahertz-Quantum-Plasma-Wave

Many applications in photonics require all-optical manipulation of plasma waves, which can concentrate electromagnetic energy on sub-wavelength length scales. This is difficult in metallic plasmas because of their small optical nonlinearities. Some layered superconductors support weakly damped plasma waves, involving oscillatory tunneling of the superfluid between capacitively coupled planes. Such Josephson plasma waves (JPWs) are also highly nonlinear, and exhibit striking phenomena like cooperative emission of coherent terahertz radiation, superconductor-metal oscillations and soliton formation. We show here that terahertz JPWs in cuprate superconductors can be parametrically amplified through the cubic tunneling nonlinearity. Parametric amplification is sensitive to the relative phase between pump and seed waves and may be optimized to achieve squeezing of the order parameter phase fluctuations or single terahertz-photon devices.