30 research outputs found
Demonstration of Optical Nonlinearity in InGaAsP/InP Passive Waveguides
We report on the study of the third-order nonlinear optical interactions in
InGaAsP/InP strip-loaded waveguides. The material
composition and waveguide structures were optimized for enhanced nonlinear
optical interactions. We performed self-phase modulation, four-wave mixing and
nonlinear absorption measurements at the pump wavelength 1568 nm in our
waveguides. The nonlinear phase shift of up to has been observed in
self-phase modulation experiments. The measured value of the two-photon
absorption coefficient was 15 cm/GW. The four-wave mixing conversion
range, representing the wavelength difference between maximally separated
signal and idler spectral components, was observed to be 45 nm. Our results
indicate that InGaAsP has a high potential as a material platform for nonlinear
photonic devices, provided that the operation wavelength range outside the
two-photon absorption window is selected
Using surface lattice resonances to engineer nonlinear optical processes in metal nanoparticle arrays
Collective responses of localized surface plasmon resonances, known as
surface lattice resonances (SLRs) in metal nanoparticle arrays, can lead to
high quality factors (~100), large local-field enhancements and strong
light-matter interactions. SLRs have found many applications in linear optics,
but little work of the influence of SLRs on nonlinear optics has been reported.
Here we show how SLRs could be utilized to enhance nonlinear optical
interactions. We devote special attention to the sum-frequency,
difference-frequency, and third-harmonic generation processes because of their
potential for the realization of novel sources of light. We also demonstrate
how such arrays could be engineered to enhance higher-order nonlinear optical
interactions through cascaded nonlinear processes. In particular, we
demonstrate how the efficiency of third-harmonic generation could be engineered
via cascaded second-order responses
Dynamic Control of Spontaneous Emission Using Magnetized InSb Higher-Order-Mode Antennas
We exploit InSb's magnetic-induced optical properties to propose THz
sub-wavelength antenna designs that actively tune the radiative decay rates of
dipole emitters at their proximity. The proposed designs include a spherical
InSb antenna and a cylindrical Si-InSb hybrid antenna that demonstrate distinct
behaviors; the former dramatically enhances both radiative and non-radiative
decay rates in the epsilon-near-zero region due to the dominant contribution of
the Zeeman splitting electric octupole mode. The latter realizes significant
radiative decay rate enhancement via magnetic octupole mode, mitigating the
quenching process and accelerating the photon production rate. A deep
learning-based optimization of emitter positioning further enhances the quantum
efficiency of the proposed hybrid system. These novel mechanisms are
potentially promising for tunable THz single-photon sources in integrated
quantum networks
Hybrid THz architectures for molecular polaritonics
Physical and chemical properties of materials can be modified by a resonant
optical mode. Such recent demonstrations have mostly relied on a planar cavity
geometry, others have relied on a plasmonic resonator. However, the combination
of these two device architectures have remained largely unexplored, especially
in the context of maximizing light-matter interactions. Here, we investigate
several schemes of electromagnetic field confinement aimed at facilitating the
collective coupling of a localized photonic mode to molecular vibrations in the
terahertz region. The key aspects are the use of metasurface plasmonic
structures combined with standard Fabry-Perot configurations and the deposition
of a thin layer of glucose, via a spray coating technique, within a tightly
focused electromagnetic mode volume. More importantly, we demonstrate enhanced
vacuum Rabi splittings reaching up to 200 GHz when combining plasmonic
resonances, photonic cavity modes and low-energy molecular resonances.
Furthermore, we demonstrate how a cavity mode can be utilized to enhance the
zero-point electric field amplitude of a plasmonic resonator. Our study
provides key insight into the design of polaritonic platforms with organic
molecules to harvest the unique properties of hybrid light-matter states.Comment: 7 pages (5 Figures) + 7 pages Appendix (5 Figures), updated versio