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Second and third order frequency correlations of speckle intensity patterns are used to characterize scattering media for multiple polarization states.
We show theoretically how electrical and pure spin AC currents can be optically injected in semiconductors via excitation of continuum carriers. The electrical current should be observable by detecting its THz radiation.
Stimulated-Brillouin-Scattering (SBS) provides passive Q-switching of a Nd:YAG-laser. Mode-coupling was actively supported by an AOM. Numerical simulations based on spectrally resolved rate equations including SBS-Stokes-shift and mode-locking explain special spectral features of this laser.
The first hyperpolarizabilities (beta) of several ldquoH-shapedrdquo second-order nonlinear optical chromophores measured by hyper-Rayleigh scattering technique exhibit much higher values than those of their monomers with slight absorption red shifting because of intra-molecular interactions.
We present a microscopic interpretation of recent differential transmission measurements of electron spin coherence in GaAs quantum wells. We show that certain unexpected features in the beat signal can reveal finer characteristics of excitonic correlations.
We present a new and very simple method for wavelength and line width measurement with a resolution in the femtometer range. The method is based on the narrow bandwidth of Brillouin scattering in optical fibers.
We have derived an explicit analytical expression for the gain of a Brillouin fiber amplifier operating in the depleted pump regime. The accuracy of the obtained formula is validated both numerically and experimentally.
An airborne aerosol lidar was flown over the CA. Central Valley to obtain aerosol profiles that were compared to Aqua satellite optical depth measurements. Such measurements provide both high vertical resolution and large spatial coverage.
Strong in-plane confinement of acoustic phonons in air-glass PCFs with sub-wavelength-scale cores is shown to result in an acoustic mode cut-off frequency, which acts like a Raman resonance. Spontaneous and photoacoustic measurements illustrate the effect.
We report on surface plasmon (SP) enhanced random lasing from a silver nanoparticle-laser dye system. The metal nanoparticle based random laser yielded a smaller bandwidth and pump fluence threshold than a dielectric based random laser.
We show that the emergence of temporally stable component in SBS Stokes emission excited by CW monochromatic pump radiation in optical fiber is a manifestation of the phenomenon of spectral self-phase conjugation.
Near-IR negative index metamaterials with substantially improved optical performance are numerically demonstrated and experimentally verified. The scaling of this structure to visible wavelengths is also discussed.
Nonlinear propagation experiments with intense THz pulses on n-type GaAs show even at room temperature coherent polarizations with lifetimes of more than 1 ps contrary to the predictions of Drude theory.
We have successfully determined the anharmonic decay time of coherent longitudinal-acoustic-phonons in GaN. The temperature dependent anharmonic decay behavior is found to agree well with the Herringpsilas theory even up to the sub-THz frequency regime.
We demonstrate how a strong coherent backward wave can be generated by forward propagating beams only. It is a dispersion effect resulting from probing a counter-propagating coherence grating by properly detuned fields.
We investigate slow-light enhancement of stimulated Raman scattering in monolithic silicon photonic crystal defect waveguides. The applied Bloch-Floquet formalism demonstrates remarkable gain enhancements up to 104 at the band-edges, while considering disorder, absorption and coupling.
We investigated many-body and radiative coupling effects on intersubband Rabi oscillations in a multiple quantum well system. Under certain conditions, radiative coupling is the dominating effect, yielding distinctively different excitation behaviors in the wells.
We discovered the linear dependence of the micro-particle size and the harmonic position of Fourier transforms of the far-field light scattering spectra over wavenumber. Based on this observation, we developed a new micro-particle sizing technique.
We have shown experimentally and theoretically that the phase control of all independent stimulated Brillouin scattering-phase conjugate mirrors (SBS-PCMs) can be achieved by self-generated density modulation without coupling the beams.
Conversion of cw light at 1.56 mum to Stokes wave was achieved with an efficiency of 27% using a 5-m-long As2Se3 chalcogenide fiber. Stokes shift and gain coefficient were 7.95 GHz and 6.08 times 10-9 m/W, respectively.
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