The transmission of high and low power acoustical transient waves via optical fibers

This paper presents preliminary results of investigations to use an optical fiber as an acoustical waveguide. In theoretical investigations the acoustical properties of the optical fibers with a clad rod structure demonstrate the fiber as an excellent acoustical waveguide. The possibility of high power ultrasonic transmission is shown. Ultrasound in the frequency range between 20 and 100 kHz, generated with magnetostrictive and piezoelectric transducers is transmitted via silica glass tapers and fibers. The coupling between the transducer and the glass has been investigated. The fiber end oscillated with an elongation up to 80 μm over a length of 1 m. The technique is useful for endoscopic surgery. The glass fiber is used as a flexible waveguide for high power transmission of ultrasound and laser radiation simultaneously. Laser ultrasound surgical therapy (LUST) allows the selective cutting of tissue and the blood coagulation with one applicator