Centre National De La Recherche Scientifique

Ecole Polytechnique

Corning Incorporated

Highwave Optical Technologies

Razvigor Ossikovski

Bernard Drevillon

Dipakbin Qasem Chowdhury

Edward F Murphy

Antonello De Martino

Donald J Sobiski

Marc Chaigneau

Jean-Yves Parey

Akli Karar

Patrick Even

Nicolas Tallaron

A multimode local probe microscope having a resonator, a first electrode, and a second electrode, an excitation source adapted to generate mechanical resonance in the resonator, a metal tip fastened to the resonator, movement mechanism for imparting relative movement between the local probe and a sample and adapted to bring the end of the tip to within a distance Z lying in the range 0 to 100 nm, and detector for detecting at least one electrical signal representative of friction forces at the terminals of said electrodes. The metal tip is electrically connected to the output second electrode and the microscopy apparatus includes amplifier and filter for amplifying and filtering signals relating to the friction forces and to the tunnelling current in a single electronic circuit, and configured for regulating the distance Z between the end of the tip and the surface of the sample.

Microscope having a multimode local probe, tip-enhanced raman microscope, and method for controlling the distance between the local probe and the sample

A Raman method and system for analysing a sample including an excitation source emitting an incident light beam, a sample holder for mounting the sample, elements for focusing the incident light beam onto the sample surface to generate a Raman scattered light having an intensity, elements for collecting the Raman scattered light to form a Raman scattered light beam, a detection system measuring intensity of the Raman scattered light beam as a function of time. The system includes at least a polarization state generator able to generate four independent polarization states or a polarization state analyzer able to analyze four independent polarization states to detect the intensity of the Raman scattered light beam and calculate a partial or complete Mueller-Stokes matrix of the sample.

Polarimetric Raman system and method for analysing a sample

The present invention provides a method of modeling an optical fiber amplifier, the method being characterized in that it comprises the steps consisting in:

Method for modeling optical fiber amplifiers

A polarization mode dispersion compensator corrects polarization mode dispersion in an optical signal having a fast polarization mode component, a slow polarization mode component and a time differential between the components. The compensator includes a phase shifter and a variable delay section. An input of the phase shifter is coupled to an optical device that provides an optical signal that exhibits polarization mode dispersion. The phase shifter functions to rotate the optical signal principal states of polarization to a desired orientation. The variable delay section includes an input, an output and at least one optical fiber delay line. The input of the variable delay section is coupled to the output of the phase shifter and the desired orientation of the optical signal principal states of polarization are substantially rotated to be in alignment with one of a fast axis and a slow axis of each of the one or more fiber delay lines. In this manner, the variable delay section functions to delay the principal states of polarization of the optical signal with respect to one another as a function of whether the principal states of polarization traverse said one of a fast axis and a slow axis of the at least one optical fiber delay line, thus reducing the time differential between the components.

All fiber polarization mode dispersion compensator

This invention concerns a spectroscopic ellipsometer modulated at a frequency (.omega..sub.m) intended for taking measurements of a sample (3). The spectroscopic ellipsometer is phase modulated, the sample being excited by external means (16) producing periodic, alternating excitation at a frequency (.OMEGA..sub.e). The measurement contains the ellipsometric parameter values (.psi., .DELTA.) of the sample, respectively in the presence of (.psi..sub.1, .DELTA..sub.1) and in the absence of (.psi..sub.2, .DELTA..sub.2) excitation of the sample, as a function of excitation frequency (.OMEGA..sub.e).

Spectroscopic ellipsometer modulated by an external excitation

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Villebon sur Yvette, France

Razvigor Ossikovski