Abstract: In a method for ultrasonic testing of objects, ultrasound is generated inside or at the surface of the object. The surface of the object is illuminated with a beam from a long-pulse laser oscillator, typically in the range 1 &mgr;s to a few 100 &mgr;s, that is substantially free of intensity fluctuations. The light from the incident beam that is scattered or reflected by the surface of the object is collected and demodulated to obtain a signal representative of the ultrasonic motion. The method allows for the use of a compact and efficient arrangement.

Abstract: Optical sources and transmitters for transmitting data in a spectro-temporally encoded light signal are provided. The optical source includes a pumped gain medium for generating ASE radiation. A wavelength dependent reflector is provided backward of the gain medium for reflecting wavebands adapted for spectro-temporal encoding. In one embodiment, a modulator and an encoder are provided outside of the source for embedding data into the generated signal spectro-temporally encoding this signal. In another embodiment, the wavelength dependent reflector acts as the encoder, and the modulator is provided inside the source.

Abstract: In a method for ultrasonic testing of objects, ultrasound is generated inside or at the surface of the object. The surface of the object is illuminated with a beam from a long-pulse laser oscillator, typically in the range 1 &mgr;s to a few 100 &mgr;s, that is substantially free of intensity fluctuations. The light from the incident beam that is scattered or reflected by the surface of the object is collected and demodulated to obtain a signal representative of the ultrasonic motion. The method allows for the use of a compact and efficient arrangement.