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.

Principle

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 superluminescent 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.

FBG Sensing System

Features

The compact size and simple electronics interface makes the I-MON Interrogation Monitors ideal for direct mounting on the customer's interrogation system control PCB.

The I-MON series has the following features:

• Fast measurement frequency
• Compact size
• Low power consumption
• No moving parts
• Environmentally stable fused silica gratings

Applications

FBG sensing:

• Vibration analysis
• Temperature measurements
• Pressure monitoring
• Strain measurements

Product overview

Below is an I-MON product overview - you can also access these conveniently through the navigator.

I-MON 80D Interrogation Monitor

The I-MON 80D is an OEM device designed for integration with the customers control PCB together with a light source suitable for the FBG sensor design. The I-MON 80D is well-suited for high-speed applications with a limited number of FBG sensors.

I-MON Series E-USB Interrogation Monitor

The I-MON Series E-USB is a high-resolution interrogation monitor with USB interface and data acquisition software providing easy setup with a laptop. The I-MON Series E-USB is well suited for high accuracy applications with many FBG sensors.

I-MON Customization

The I-MON design and specifications can be modified to suit a range of customer requirements.