Light beam excited piezoelectric vibrator for passive dipole - uses localised incident optical radiant periodically modulated to excite lamina close to resonant frequency

The resonator consists of a quartz lamina (9) whose principal faces are metallised (7,8) to form electrodes. The lamina is suspended by two metallic rods (10,11) joining the middle of the metallisations to a base (12) having two electrical pins (13,14). The assembly is protected by a glass envelope (15) permeable to radiation. The resonator is excited by an amplitude modulated beam (11) of optical radiation of frequency f. The beam whose source may be a He-Ne laser (1) is modulated by an acousto-optical or electro-optical modulator (2) electrically controlled by a tunable alternating generator (5). A sinusoidal voltage appears at the terminals (13,14) on impact (6) of the light beam with one of the metallisations and when the modulation frequency f approaches the natural resonance frequency of the piezoelectric resonator. The metallisation transforms the optical energy into heat which produces a local dilation of the piezoelectric material. L'INVENTION SE RAPPORTE A L'EXCITATION DES RESONATEURS PIEZOELECTRIQUE COMPOSES D,ELECTRODES 7, 8, 17, 18 ENCADRANT UNE LAMELLE PIEZOELECTRIQUE.L'INVENTION A POUR OBJET UN PROCEDE D'EXCITATION OPTIQUE D'UN TEL RESONATEUR CONSISTANT A FAIRE INTERAGIR UN FAISCEAU OPTIQUE INCIDENT 4 PORTEUR D'UNE MODULATION PULSATOIRE TEMPORELLE OU SPATIALE AVEC UNE METALLISATION 28 PORTEE PAR LADITE LAMELLE 16, AFIN D'OBTENIR UN REGIME D'OSCILLATION FORCEE DANS LA PLAGE DE RESONANCE DUDIT RESONATEUR.L'INVENTION S'APPLIQUE NOTAMMENT A LA CAPTATION SELECTIVE D'UN RAYONNEMENT MODULE ET A LA REALISATION DE DISPOSITIFS AUTO-OSCILLATEURS.