Abstract: A description is given of a sensor for measuring the UV fraction of a radiation, comprising a photochromic transducer consisting of a photochromic material (3) with characteristics of reversible photochromism, whose absorbance varies as a function of the UV fraction of the radiation (R) incident on the photochromic material. An optical path (7) is provided to guide a light signal through said photochromic material and collect a return light signal, whose value is proportional to the level of absorbance of the photochromic material.

Abstract: A description is given of a method for the construction of a fiber-optic sensor in which a chromophore is fixed on a support and said support is linked to at least one optical fiber for the transmission and reception of a light signal. According to the invention, the end of the optical fiber (F) is heated and brought to a softening temperature, and the support (S) is immobilized on the optical fiber (F) by partially incorporating it in the softened portion of the optical fiber and subsequently cooling and solidifying the optical fiber.

Abstract: A device for transferring the energy emitted by a high power laser onto a target characterized in that it comprises two guides of optical fibre having step index refraction distribution and at least a plastic material coating. The first guide, stiffly coupled to the laser source, is a variable section fibre with an input face of larger diameter. Guide is the second one by a uniform or variable section fibre with a larger diameter near the output terminal. The two guides are joined by a low leakage optical fibre connector, and between them an adapter can be interposed if the output section of the first guide of fibre does not coincide with the input section of the second guide of fibre. The variable section fibre can be drawn from a pre-moulded or melted material, with the speed controlled by an electronic circuit. Different kinds of pots can be utilized in order to obtain the fibre plastic coating.

Abstract: An optical fiber temperature thermometer uses a thermochromic substance having optical absorption peaks which vary with temperature within a first waveband, and having substantially constant absorption with temperature in a second waveband. The radiation employed is in a wide band to include the first and second wavebands, and the radiation, reflected and attenuated as a result of the passage through the thermochromic substance, is split into two selected beams and filtered in narrow band pass filters for the first and second wavebands, to supply optical signals to respective detectors whose outputs are divided to produce a ratio signal representative of the temperature. The sensor is sufficiently compact for biomedical use, and, being unaffected by electromagnetic fields, is useful in regions of high tension or in microwave heating.

Abstract: A device for transferring the energy emitted by a high power laser onto a target characterized in that it comprises two guides of optical fibre having a step index refraction distribution and at least a plastic material coating. The first guide, stiffly coupled to the laser source, is a variable section fibre with an input face of larger diameter. The second guide is a uniform or variable section fibre with a larger diameter near the output terminal. The two guides are joined by a low leakage optical fibre connector, and between them an adapter can be interposed if the output section of the first guide of fibre does not coincide with the input section of the second guide of fibre. The variable section fibre can be drawn from a pre-molded or melted material, with the speed controlled by an electronic circuit. Different kinds of pots can be utilized in order to obtain the fibre plastic coating.