Centre National Detudes Spatiales

Office National D'etudes Et De Recherches Aerospatiales

Office National D'etudes Et De Recherches Aerospatiales (Onera)

François Lemaître

Philippe Hébert

Xavier Orlik

Thibault Dartigalongue

Nicolas Cezard

A LIDAR-type device for a remote spectroscopy of a matter includes an optical emission channel that includes a laser source and an optical waves frequency generator to generate a first comb, a second comb, and a local comb. Each comb includes at least one stripe. A transmit telescope emits an emission signal. A reception channel includes a receive telescope that receives a signal reflected by the matter traversed by the emission signal and a detection system that detects a first beat signal of the at least one stripe of the local comb with the corresponding first stripe of the first reflected comb, a second beat signal of the at least one stripe of the local comb with the corresponding second stripe of the second reflected comb, and a third beat signal of the at least one first beat signal with the at least one second beat signal.

LIDAR for heterodyne detection by a local oscillator and a dual probing beam, at one or several simultaneous frequency(ies), and LIDAR detection method by dual heterodyning detection

A method of generating frequency combs composed of a predetermined number of rays, wherein the method includes the modulation of a main ray generated by a laser source (), by a first radiofrequency signal at a first frequency value, by a second radio frequency signal at a second frequency value, and by a third radio frequency signal at a third frequency value. The second frequency value is equal to twice the first frequency value. The third frequency value is equal to three times the first frequency value.

Method of frequency comb generation, associated generation module, remote spectroscopy method and associated spectroscopy device

Disclosed is a remote spectroscopy device of the LIDAR type including a module for generating an emission signal, an emission module for sending the emission signal toward a targeted material, a receiving module for receiving a response signal and a module for postprocessing of the response signal to determine a composition of the targeted material. The generating module includes at least two laser sources, each laser source being able to generate a laser signal at a predetermined wavelength, an upstream mixer able to mix the laser signals generated by the different laser sources, and a first modulator able to modulate the composite signal at a first modulation frequency to form the emission signal.

Remote spectroscopy device with a composite laser source and associated remote spectroscopy method

The invention relates to the field of seismology and volcanology, especially the monitoring of the sites in question, called 'unstable sites', and more specifically the monitoring of a fault on such a site. In this respect, the invention especially relates to a reflective assembly to be arranged on a monitored site, the site being monitored from an observation point from which an electromagnetic wave is directed towards the reflective assembly. The invention also relates to a method for monitoring a site by means of such a reflective assembly.

Growing community of inventors

St Orens de Gameville, France

François Lemaître