In this paper, the gain spectrum and the saturation behavior of one-pump fiber optical parametric amplifiers (1-P FOPAs) are investigated by taking into account the fourth-order dispersion coefficient b4 in the analysis. The results show that it is necessary to consider b4 in the analysis when the wavelength difference between the signal and pump waves is large enough and/or whenever the pump w...

The contribution of water to the quantitative determination of hemoglobin concentration and saturation by near-infrared spectroscopy in turbid media was investigated. The study consisted of in vitro measurements of an aqueous suspension containing Liposyn, bovine blood, and yeast buffered at pH 7.2. The optical coefficients of the medium (ma;0.03 to 0.08 cm −1, ms8 ; 6 cm −1 at wavelengths of 7...

We experimentally investigate optical storage with electromagnetically induced transparency in a dense cold (85)Rb atomic ensemble. By varying the optical depth (OD) from 0 to 140, we observe that the optimal storage efficiency has a saturation value of 50% as OD>50. Our result is consistent with that obtained from hot vapor cell experiments.

Repetition-rate multiplication has been shown by use of a fiber ring oscillator with a semiconductor optical amplifier as the gain medium and by use of fast saturation and recovery of the amplifier from an external optical pulse train. Repetition-frequency multiplication up to 6 times and up to 34.68-GHz frequency have been achieved.

Intervalley scattering of hot electrons during high-field transport in transverse-field photorefractive quantum wells induces a nonlocal optical response in which photoinduced changes in the refractive index are spatially shifted relative to the optical stimulus, providing an avenue for optical gain. We demonstrate that the onset of the photorefractive phase shift coincides with the onset of ve...

This paper presents the nonlinear dynamics of laser cooled and trapped cesium atoms placed inside an optical cavity and interacting with a probe light beam slightly detuned from the 6S1/2F = 4 to 6P3/2F = 5 transition. The system exhibits very strong bistability and instabilities. The origin of the latter is found to be a competition between optical pumping and non-linearities due to saturation...

Optical reorientational nonlinearity in twisted nematic liquid crystalline planar waveguide is analyzed theoretically. It is shown that optical nonlinearity for guided modes in analyzed waveguides can be approximated by saturation nonlinearity. Predicted nonlinearity is large enough to observe e¤ects like spatial solitons formation with milliwatts of light power. PACS: 42.65.Wi, 42.70.Df

Abstract We perform a qualitative and quantitative analysis of various multi-frame color optical flow methods for synthetic and real panning and zooming image sequences. We show that optical flow accuracy improvement can be slightly improved if color images are available instead of gray value or saturation images. We show the usefulness of a directional regularization constraint for computing o...

In the work, analytic expressions describing the behaviour of a strongly saturated nonlinear optical amplifier are deduced. These expressions make possible the calculation of the mean and variance of the amplified light photon number. Results are compared with those obtained by the numerical resolution of the photon density matrix equation, and good accordance is observed in the strong saturati...

We have used continuous-wave (CW) and frequency-domain spectroscopy to investigate the optical properties of the newborn piglet brain in vivo and non-invasively. Three anaesthetized, intubated, ventilated and instrumented newborn piglets were placed into a stereotaxic instrument for optimal experimental stability, reproducible probe-to-scalp optical contact and 3D adjustment of the optical prob...