Optical fibers are long known for the benefits they have. They have been revolutionary since they were invented. Even now researchers keep modifying the existing structure of these fibers and create better structures. One such upgrade is of making the optical fibers capable of identifying the material it is being used for/with. The constituents around the fiber would be detected, be it liquid or solid.

These fibers have served several purposes in the modern world. They have functioned as detectors to know the changes in temperature and pressure. In structures like bridges and gas pipelines, where temperature and pressure matters a lot, it has been successful. Now EPFL researchers have come up with a new idea of making these fibers capable of identifying what is the material they are being placed with. The sound waves created by different objects is not the same, and light beam along with the power of resonance can help accomplish this task. 

A study was conducted by GFO – the group for fiber optics-  which found that optical fiber made of glass could transmit light as per four parameters which are –  intensity, phase, polarization, and wavelength. The fiber thus acts like a sensor which can identify cracks on structures or other abnormalities in temperature, pressure etc. Now attempts are being made to make the fiber capable of finding what is happening around it by knowing the details of the material disrupting its path. 

To achieve this a hyper-frequency wave that can bounce back the fiber’s wall will be added to the optical fiber. The echo produced will vary at different locations and for different materials. This echo will serve as a fingerprint to map the fiber’s surroundings. The echo can however not disturb the light waves propagating inside the fiber since they are very faint. The method has been used for water, and alcohol and has proved to be successful. This method can help to identify leakages, the density of fluids, their salinity and has several other potential applications.

All this is possible because of a simple time-based method in which each wave is generated after a time lag so the delay is reflected in the beam’s arrival too. The disturbances along the way for the wave can be determined along with their location using this method. Till now the issues for only ten meters can be detected using this technology but the team is striving to increase the efficiency as well as the accuracy of the method.