FIELD: physics.SUBSTANCE: laser radiation modulator has a laser, a relief diffraction grating with a rectangular profile, which reflects a beam of the modulated laser radiation, the depth of which is greater than a quarter of the wavelength of the modulated laser radiation, and a platform which is connected to an electromechanical vibrator mounted on a fixed base. The relief diffraction grating is made from plates which are formed into stationary groups and groups of movable plates capable of back-and-forth movement, placed in spaces between plates of the stationary group, the ends of which are shifted with respect to the ends of the stationary group in a direction which is perpendicular to surfaces facing the laser. The stationary group is connected to the base by a precision adjustment mechanism, and the group of movable plates is placed on the platform which is connected by an elastic suspension to the base and the electromechanical vibrator. The ends of plates facing the laser beam have a flat surface which reflects laser radiation.EFFECT: high accuracy of positioning a laser beam.1 dwg

Laser radiation modulator

An optical pulse generator comprises a signal source, an excitation light source, a first optical fibre, a first lens, a diffraction grating, a second lens, a second optical fibre and an optical switch. Herein, signal beams produced form the signal source are transmitted through the first optical fibre, first lens, diffraction grating and second lens in turn, so that a signal beam having a desired wavelength is selectively outputted. This signal beam is converged onto and is incident to a terminal portion of the second optical fibre which is excited by an excitation beam produced from the excitation light source. Under an operation of the optical switch, the terminal portion of the second optical fibre is vibrated, resulting that an optical path to be formed between the first optical fibre and the second optical fibre is periodically opened or closed. Thus, an optical pulse of which amplitude is controlled and of which pulse width is also desirably controlled is outputted form the second optical fibre. Preferably, the second optical fibre is made of a predetermined material including a rare-earth material.

Masaaki Furahashi

Papers

Optical pulse generator