Abstract: Disclosed is an acoustic resonance spectrometry system for analysing a sample, which includes an optical pump-probe device adapted to generate a pump beam and a probe beam, the pump beam being consisted of a series of ultra-short pump light pulses having a repetition frequency in the spectral domain of the gigahertz, the pump beam being directed towards an optoacoustic transducer to generate a periodic grating of coherent acoustic phonons in the sample, the probe beam being directed towards the sample to form a scattering beam of the probe beam on the grating of phonons, a frequency variation device being adapted to vary the repetition frequency of the pump beam in a spectral range and a photo-detection system configured to measure a scattering signal as a function of the repetition frequency in the spectral range.

Abstract: Disclosed is a dermatological diagnostic and treatment system including a light source device, a light flow collecting device, a spectroscopic measurement device, and a computer. The light source device includes a laser source tunable in wavelength inside the spectral range, the laser source being tunable in duration and/or rate and the laser source being adapted to generate a second treatment laser beam of high intensity at said first wavelength towards the epidermal surface. The dermatological diagnostic and treatment system further includes a temperature sensor and a feedback device, the temperature sensor being arranged to record a temperature measurement signal of the epidermal surface as a function of the application of the second laser beam. The feedback device is configured to modify the duration and/or rate of the laser pulses as a function of the temperature measurement signal.

Abstract: Disclosed is an acoustic resonance spectrometry system for analysing a sample, which includes an optical pump-probe device adapted to generate a pump beam and a probe beam, the pump beam being consisted of a series of ultra-short pump light pulses having a repetition frequency in the spectral domain of the gigahertz, the pump beam being directed towards an optoacoustic transducer to generate a periodic grating of coherent acoustic phonons in the sample, the probe beam being directed towards the sample to form a scattering beam of the probe beam on the grating of phonons, a frequency variation device being adapted to vary the repetition frequency of the pump beam in a spectral range and a photo-detection system configured to measure a scattering signal as a function of the repetition frequency in the spectral range.

Abstract: The invention relates to a laser system provided with a laser radiation device (1) in which the radiation frequency is controlled by a heterodyne servo circuit particularly using an interferometric circuit (15). Said interferometric circuit comprises a coil of optical fibres (17) which provide a reference for correcting the laser radiation frequency. To obtain good results in the field of spectral purity, all the elements involved in the laser radiation are fibres and the connections thereof are provided by optical fibres. The invention can be used for lasers requiring high spectral purity.