Ibsen Photonics’ I-MON Interrogation Monitors set new standards for fast, real-time spectrum monitoring of FBG sensor systems.
Through a unique combination of very fast measurement frequency, low power consumption and compact size, they are ideally suited for a broad range of applications. The I-MONs offer straightforward integration and meet industrial qualification standards.
The FBG sensor is a short piece of optical fiber with a periodic modulation of the refractive index in the optical fiber.
The periodic modulation of refractive index is generated by the interference pattern created from the phase mask, and it creates a narrow filter response with peak reflectivity at a wavelength determined by the period of the FBG.
A broadband source such as a super luminescent diode (SLED) or an amplified spontaneous emission (ASE) source can be used as light source for the FBG sensing system.
When the FBG is mounted on a structure, it may be stretched or compressed due to structural changes of the structure. This causes a change in the FGB period, and the peak reflectivity of the FBG is shifted accordingly to λi+Δλ. Each fiber can contain a multitude of FBG sensors all having different peak reflection wavelength.
Determining the peak reflection wavelength and shift in peak wavelength is the basis of FBG sensing, since measurement of the reflected wavelength can be converted to parameters such as strain, pressure, vibration and temperature. The I-MON Interrogation Monitors are designed to measure the reflection spectra from the FGB sensors, and will provide data to the control electronics or PC for peak determination.