Abstract: Device for the detection of optical parameters consisting of a first sensing element that is sectioned into a plurality of equal regions each able to produce an electric signal, proportional to the power of the incident laser beam. Before said first sensing element with respect to the direction of the incident laser beam, at least a second sensing element is provided, lined up with the first sensing element and thermally insulated from it, that has a hole with a shape equal to the shape of the incoming laser beam and with dimensions increasing with the distance from that first element.

Abstract: Device for the characterization of a laser beam according to a "Knife edge" method as defined by Standard ISO 11146. The device has a lens for the focalization of an incident laser beam, and a detector. Interception elements are located between said lens and said detector in order to intercept sequentially the focalized laser beam in a plurality of different positions along its axis of propagation. The interception elements are suitable to allow, in each one of said positions, the passage of a progressively increasing (or decreasing) portion of the vocalized laser beam starting from a condition of substantially total (or null) interception up to a condition of substantially null (or total) interception.

Abstract: A system for measuring the "time of flight" or transfer time of a sound wave in a gas by using the relation between the gas temperature and the velocity of the sound wave in the gas, and calculating therefrom the temperature of the gas. The system comprises an emitter, which generates a sound which is coherent in phase, at one frequency or a group of frequencies; a self-correlating decoder and a receiver, which is associated with the emitter, and which sends the sound to a filter system and to an assembly controlled by a microprocessor, which processes the signal coming out of the filter system in a shape similar to a Hamming wave shape in order to determine the absolute maximum value and therefrom determine the transfer time. With this knowledge, it is easy to relate the transfer time to the distance traveled between the emitter and receiver and the known properties of the gas, in order to arrive at the temperature of the gas through which the sound has been sent.

Abstract: A superluminescent source emits a wide-band light beam, that is frequency modulated by a filter with a pass band centred on a frequency that is made to vary according to a predetermined law so as to frequency modulate the light beam. Means for splitting and recombining beams determine a mutual phase shift between two components of the beam that depends on the physical magnitude to be measured and is detected by a detector as an indication of the value of the magnitude itself.

Abstract: In a laser apparatus for measuring the velocity of a fluid, a measurement laser light beam (M) fed into the fluid and scattered by a particle within the fluid is made to interfere with a reference laser light beam (R) to generate an interference signal based on the velocity of the particle; the apparatus comprises a low-coherence laser source (10) and interferometric means (11, 12) which split the light beam of the laser source (10) into the stated reference light beam (R) and measurement light beam (M), and cause the reference light beam (R) derived from the laser source (10) to interfere with the backscattered component resulting from the scattering of the measurement light beam (M).

Abstract: An improved pressure/temperature probe whose accuracy will not be affected by the pressures and temperatures to which it is subject or by the resistance of the connecting cables. The probe includes a separate pressure transducer and temperature transducer which are connected in series to a constant current source. In addition to the pressure reading taken by the pressure probe, a temperature reading of the pressure probe is derived from the pressure probe. This temperature reading provides the actual temperature of the pressure probe and permits highly accurate temperature correction. The pressure probe is constructed and arranged so as to have a high thermal time constant while the temperature probe is constructed and arranged to have a low thermal time constant.

Abstract: An improved process for producing a protected optical fiber cable and the cable produced thereby. The process for producing the cable includes the insertion of a relatively thin optical fiber within a relatively large metal tube by means of flowing a fluid around the fiber and through the tube. As the water flows within the tube, the optical fiber becomes progressively entrained within the tube. Additional steps of coating the fiber with a releasable protective coating and unwinding the fiber from a reel within a container are also disclosed.