Aerospace & Defense
Fiber optics are increasingly becoming the backbone of high-tech equipment such as military jets. A fiber optic network integrated into the aircraft enables the various technological building blocks that make it up to communicate efficiently and durably with each other. The same philosophy can be found on boats, helicopters and a multitude of complex, next-generation vehicles/aircrafts. OBRI It is therefore necessary to characterize this fiber optic network, which is usually difficult to access because it is integrated into the equipment. The OBR 6200 series, based on OFDR technology, is a solution to this problem, because it's an easy-to-use, rugged device able of operating autonomously (with integrated battery and display) using OFDR technology.
Another important application in aerospace and defense is LIDAR systems. Laser remote sensing, or LIDAR, is a remote measurement technique based on the analysis of the properties of a beam of light reflected back to its emitter by the target. The principle is similar to that of SONAR, except that this time the wave involved is not acoustic but electromagnetic (and therefore operates in a vacuum/diluted medium). LIDAR technology determines the speed of the target object by using a laser with a narrow emission spectrum (a specific frequency) and measuring the frequency shift of the wave reflected by the target (Doppler-Fizeau effect).
This is why our RIO lasers can be found in some of these LIDAR systems, thanks to their spectral finesse ranging from 15kHz to < 1kHz in the infrared range (1060nm to 1550nm). Another notable feature of these lasers is their low intensity noise and low phase noise (see diagram above). The intensity noise of a laser affects the fluctuation of the average output power over time. Phase noise, on the other hand, is responsible for laser output frequency jitter. For the development of increasingly accurate LIDAR systems, it is therefore necessary to integrate laser sources with low phase noise to provide an ultra-fine AND ultra-stable spectral reference over time.
Rayleigh interrogators (such as the Hyperion) are also used to monitor classified sites and prevent site intrusion. In this case, the site is equipped with a multitude of sensors in areas sensitive to intrusion. It is then possible to define, via the interrogator, alert thresholds which, once crossed, trigger an alarm. When the area to be covered is relatively large, it is preferable to use a distributed measurement system such as DAS (Distributed Acoustic Sensing), capable of covering a much larger surface area. In this case, the fiber is integrated into the wire mesh surrounding the site to be monitored, and can also be buried beneath the ground (see picture below). The fiber is then able to detect an approaching vehicle or pedestrian.
