Abstract: A pressure-measuring device including an optical fibre with a thinned portion, a laser, called the heating laser, arranged to emit an optical wave, called the heating wave, into the thinned portion, a measuring means including a sensor that is arranged to measure a backscattered optical wave that is generated by an optical wave, called the interrogation wave, and that originates in the thinned portion of the optical fibre, and a processing unit arranged and/or programmed to measure a pressure of a fluid, preferably a gas, encircling the thinned portion, on the basis of the measurement of the backscattered wave.

Abstract: A process for delaying a useful optical signal (P1) having a wavelength value ? between 0.2 ?m and 3 ?m, with respect to a reference optical signal (P2) having the same wavelength value ?. The process includes having the useful optical signal propagate along a tapered fiber portion. A length of the tapered fiber portion can be varied using stretching means that are light, less cumbersome and less expensive compared to those necessary for a standard optical fiber. In addition, the delay value which is effective for the useful optical signal can be varied over a wide range. Such process can be useful for interferometry measurements in particular.