The light that is sent to the sensor is focused onto the 50μm core of the sensor’s multi-mode fiber. This focusing is accomplished with the help of another 20X objective lens mounted to an X − Y axis translator which focuses the light onto the fiber core which is able to adjust via a Z-axis translator which has the FPI fiber’s ST connector (ST) attached to it. The light travels through the fiber and into the sensing cavity and then back reflects out the same optical axis it came in. This back reflected light passes through the 20X objective lens and is collimated into the beam splitter and once through the beam splitter the light is sent into the photodetector (PD) (DET10A, Thorlabs Inc, USA). The photodetector’s output is digitized by a 16-bit data acquisition system (DAQ) (USB 6229-BNC, National Instruments, USA) and a processing computer (PC) is used to calculate the strain values