The detection properties of a chalcopyrite zinc germanium diphosphide (ZnGeP<sub>2</sub>, ZGP) electro-optic (EO) crystal, having thickness of 1080 μm and cut along the <012> plane, is studied in the terahertz (THz) frequency range. Outstanding phase matching is achieved between the optical probe pulse and the THz frequency components, leading to a large EO detection bandwidth. ZGP has the ability to measure frequencies that are 1.3 and 1.2 times greater than that of ZnTe for crystal thicknesses of 1080 and 500 μm, respectively. Furthermore, the ZGP crystal is able to detect frequency components that are ≥4.6 times larger than both ZnSe and GaP (for crystal thicknesses of 1080 μm) and ≥2.2 times larger than ZnSe and GaP (for crystal thicknesses of 500 μm).
In this work, we summarize recent findings on ultrafast nonlinear and strong-field phenomena in silicon-loaded nanoplasmonic waveguides. Coupling ultrafast λ= 1:55 μm pulses into such structures gives rise to both high- efficiency third harmonic generation (THG) and ponderomotive electron acceleration. We show THG efficiencies of 2.3 ×10 5 in waveguides with an ultracompact footprint of 0.43 μm<sup>-2</sup>, resulting in visible green light emission. Remarkably, broadband white light emission is observed as well. This phenomenon is found to originate from an electron avalanche induced by the ponderomotive acceleration of electrons generated via two photon absorption. Thus, this nanoplasmonic device presents a versatile platform for realizing ultrafast nonlinear phenomenon within all-optical circuitry.
We propose a novel hybrid ridge-plasmonic waveguide Faraday rotator for high-speed polarization manipulation in nanoplasmonic circuitry. Our design, based on bismuth-substituted yttrium iron garnet (Bi:YIG), provides a unique geometrical mechanism of phase matching both the plasmonic TM and photonic TE waveguide modes, and hence facilitates effective mode conversion via the Faraday effect. This structure yields 99.4% mode conversion within 830 μm, which is easily attainable within the long (>1mm) propagation lengths of the two supported modes. Furthermore, our simulations show that the application of magnetic field transients can alter the magnetization of the Bi:YIG to actively switch the polarization state, or produce a polarization oscillator at frequencies up to 10GHz. This structure is envisioned to play a fundamental role in future integrated nanoplasmonic networks.
In this work, we propose a magnetoplasmonic modulator for nonlinear radio-frequency (RF) modulation of an integrated optical signal. The modulator consists of a plasmonic Mach-Zehnder interferometer (MZI), constructed of the ferrimagnetic garnet, bismuth-substituted yttrium iron garnet (Bi:YIG). The transverse component of the Bi:YIG magnetization induces a nonreciprocal phase shift (NRPS) onto the guided optical mode, which can be actively modulated through external magnetic fields. In an MZI, the modulated phase shift in turn modulates the output optical intensity. Due to the highly nonlinear evolution of the Bi:YIG magnetization, we show that the spectrum of the output modulated intensity signal can contain harmonics of the driving RF field, frequency splitting around the driving frequency, down-conversion, or mixing of multiple RF signals. This device provides a unique mechanism of simultaneously generating a number of modulation frequencies within a single device.
In this work, we present the design of integrable magnetoplasmonic isolators and modulators, based on a longrange magnetoplasmonic waveguide structure. With the addition of magnetized cerium-substituted yttrium iron garnet waveguides and planar samarium-cobalt biasing magnets to a Mach-Zehnder interferometer (MZI), we show that an efficient isolator architecture can be implemented with insertion loss of 2.51 dB and an isolation of 22.82 dB within a small footprint of 6:4 x 10<sup>-3</sup> mm<sup>2</sup>. Additionally, employing bismuth-substituted yttrium iron garnet in a MZI and transient magnetic fields from nearby transmission lines, we propose a high-speed electrical-to-optical clock multiplier. Such a device exhibits a modulation depth of 16.26 dB, and an output modulation frequency of 279.9 MHz. Thus, input clock signals can be multiplied by factors of 2:1 x 10<sup>3</sup>. These devices are envisioned as fundamental constituents of future integrated nanoplasmonic circuits.
Our experiments demonstrate ultrahigh resolution imaging of localized plasmonic fields with a scanning tunneling
microscope (STM). Plasmons are optically excited on gold nanoplasmonic antennas, and the fields localize in the
nanometer scale voids and chasms between the gold grain boundaries. The plasmon field manifests in the nonlinear
tunneling junction as a rectified tunnel current signal, which can be analyzed to produce maps of the plasmon field
localization with an unprecedented resolution of 1nm. The experimentally observed signals are conclusively attributed to
the plasmon excitation. Extensions of this procedure have the potential to produce plasmonic field distribution maps with