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We demonstrate an integrated, CMOS compatible, multiple wavelength source based on hyper-parametric oscillation via MI (FWM) gain in a high index doped silica glass ring resonator. We obtain lasing with wavelength spacings from 200 GHz to > 6 THz, with a threshold of 54 mW. This device has promise for telecommunications and on-chip WDM optical interconnects for computing.
Cadmium sulfide (CdS) nanoparticles (NPs) were successfully incorporated in three kinds of CTAB-templated mesoporous silica materials: mesoporous silica spheres (MSS) suspended in ethanol solution, MSS spin-coated on glass slide and dip-coated mesoporous silica thin film (MSTF). The optical nonlinearities of these three composites as well as CdS NPs loaded in P123-templated MSTF were measured with...
Second order nonlinearity can be created in silica fibre by poling. Practical electro-optic switches have been elusive. This paper describes new developments demonstrating real prospects for applications in sensing and second harmonic generation.
We demonstrate the power delivering between two silica fiber tapers through a bridging wire made of a highly nonlinear tellurite glass. The Fresnel reflection at the splicing point is significantly reduced by angled-cut fiber tapers.
A potential mechanism for high-temperature integration of a recently developed GaAs-based optically triggered power transistor (OTPT) to a SiC DMOSFET for photonic control of power flow is outlined and experimentally demonstrated over a range of switching frequencies and duty cycles. It was found that the switching dynamics of the SiC DMOSFET varies with the case temperature due to a change in the...
Properties of white light continuum generation are investigated experimentally and numerically in a highly nonlinear photonic crystal fibre (PCF). The initial stage of an ultra broad-band supercontinuum generation (SCG) in normal and anomalous dispersion regime is pointed out. We found that, for low pump power, the symmetric broadening is mainly due to the effect of self phase modulation. With the...
Silicon is an important photonic medium - and can be exploited in various waveguide devices, including sensors, that exploit its high refractive index and technological capabilities. Its oxide, silica, extends what is possible.
Ever since slot waveguide was first proposed, its unique photon confinement characteristic has attracted a lot of interest. Its applications in several areas such as silicon light emission device, nonlinear optical device, and optical bio detection have been proposed and experimentally verified. Different merit functions for device design have also been proposed for some specific applications. This...
In situ observation of inelastic light scattering in the boson region during heating was performed in glassy fresnoite (Ba2TiSi2O8) with a homogenenous nucleation tendency to elucidate its nanocrystallization dynamics. The nucleation and crystal-growth processes are discussed on the basis of our boson observation results, Cabral's thermodynamic data, and other studies.
We propose a highly nonlinear polarization maintaining octagonal photonic crystal fiber possessing flattened dispersion properties within 0.98~1.26 mum wavelength range. The PCF can be used for broadband supercontinuum generating light source in OCT medical applications.
We use controlled hole collapse in photonic crystal fibres to reduce the splice loss between dissimilar fibres. We also describe a hollow-core PCF as a support for a waveguide core made from silica aerogel.
We show experimental evidence for cold avalanche and demonstrate how it can be distinguished from the traditional avalanche process. We analyse the nonlinear absorption of 800 nm, ultrashort pulses focused inside fused silica glass to study the ionization mechanisms. The light is focused tightly inside the glass using a microscope objective so as to avoid surface damage and self phase modulation....
The authors report on the ultrafast modulation of propagating fs SPP signal via direct optical excitation of the metal component of an aluminium/silica waveguide and investigate spectral dependence of the effect and its kinetics. The authors also analyse numerically the nonlinear SPP pulse propagation regimes, including self-focusing, pulse compression and solitons, supported by the nonlinearity of...
Experiments in extreme nonlinear optics, in attosecond physics, and in frequency metrology depend on precise control of the carrier-envelope phase (CEP) of femtosecond oscillators and amplifier systems. Today intracavity fine CEP control relies mostly on pump-laser amplitude modulation, which is intrinsically fast but has only a limited control range and adjusts the CEP by varying the laser power...
In this talk, we present our recent results on investigations of microresonators at the University Jena. The work is divided into two parts. In the first part we focus on fabrication and characterization of different nonlinear effects in single silica and hybrid silica-silicon disc microresonators. In the second part we discuss spectral characteristics and light distribution in coupled micro disc...
In this paper a bistable operation of silica micro disc resonators and hybrid ones made of silica/silicon has been investigated experimentally. It has been found, that in a hybrid silica/silicon micro resonators a bistability effect has an opposite sign in comparison with a silica disc micro resonator. The bistable behavior of silica micro resonators caused by a thermal nonlinearity exhibits transmission...
In this paper, we present a new concept for an ultra fast pulse picker, consisting of a tapered diode amplifier and a high-speed high-current transistor switch. The transistor switch is realized using a GaN high-electron mobility transistor (HEMT), which offers low parasitic capacitances und high current capabilities together with high switching speed. Moreover, the SiC transistor substrate gives...
Photonic crystals - the artificial materials with periodic dielectric structure with a period close to the wavelength of electromagnetic waves - are promising materials for nonlinear optics. Two new nonlinear optical phenomena have been found out recently in photonic crystals: photonic flame effect (PFE) and stimulated globular scattering. This paper studies properties of PFE, SGS, and stimulated...
In this work, we have used a tapered fiber based pump-probe scheme to resonantly drive crown-type mechanical modes in a silica microtoroid. Crown modes exist in frequency degenerate orthogonal pairs. However, we demonstrate that due to energy and momentum conservation one mode is preferentially driven using this technique. To date, this has not been observed experimentally as studies have focused...
Silicon photonics is an increasingly active and exciting research topic that owes much to the excellent optical material properties of silicon. Crystalline silicon has a high refractive index (~ 3.48 @ 1.5 mum), a low loss transmission window between 1.2 mum - 6.7 mum, and a large third order optical nonlinearity (orders of magnitude greater than that of silica) making it a highly attractive material...
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