Centre National De La Recherche Scientifique

Université De Rennes 1

Université De Rennes I

Marc Vallet

Mehdi Alouini

Goulc'hen Loas

François Bondu

Marco Romanelli

Marc-Olivier Brunel

Gwennaël Danion

Marc Brunel

Many applications require the use of lasers with short optical ray lengths. However, at present, there is no module that makes it possible to refine a ray from a light source in a satisfactory manner, in particular one from a semiconductor laser. The invention relates to a spectral refinement method (), a device with refined spectral line () comprising at least one light source () and a spectral refinement module (). The latter includes at least one first coupler (), a Brillouin resonator () and a modulator ().

Spectral narrowing module, refined spectral line device and method therefor

The invention concerns an oscillator generating a wave composed of a frequency of on the order of terahertz from a beat of two optical waves generated by a dual-frequency optical source. The oscillator includes a modulator the transfer function of which is non-linear for generating harmonics with a frequency of less than one terahertz for each of the optical waves generated by the dual-frequency optical source, an optical detector able to detect at least one harmonic for each of the optical waves generated by the dual-frequency optical source and transforming the harmonics detected into an electrical signal, a phase comparator for comparing the electrical signal with a reference electrical signal, and a module for controlling at least one element of the dual-frequency optical source with a signal obtained from the signal resulting from the comparison.

Oscillator for generating a signal comprising a terahertz-order frequency using the beat of two optical waves

In the field of the production of very high frequencies, for example from 1 gigahertz to several terahertz, by beating the frequencies of two laser beams together, a device includes a resonant optical cavity having very stable dimensions receiving the beams, with for each beam, an interrogation device of the resonant cavity supplying an electrical signal representing the difference in frequency between the light frequency of the beam and a resonance frequency of the resonant cavity. The frequency of each beam is servo controlled to minimize the frequency difference observed. The laser beams are produced by a dual-frequency laser producing two beams of different frequencies and orthogonal polarizations. A polarization separator is used for separate servo control of the beams according to polarization, and a polarizer is placed behind a main output of the resonant cavity producing an electromagnetic beam mixing the two polarizations and amplitude-modulated at the beat frequency.

Device for producing high frequencies by means of light frequency beating

Growing community of inventors

Thorigne Fouillard, France

Marc Vallet