FSI M4 Interrogator

MX Interrogators
New MX Family of Industrial Grade Optical Sensing Instruments
January 5, 2021
F8 interrogator
FSI M8 Interrogator
January 12, 2021

M4 Interrogator

Click here to download the Datasheet


The M4 optical sensing instrument is an economic commercial-grade interrogator, featuring 4 monitoring channels. Enclosed in a field-deployable enclosure, the instrument can be operated in full-spectrum and in sensor peak detection modes. The M4 is optimized for both static and dynamic measurements of up to 30 Fiber Bragg Gratings (FBG) based sensors on each of its 4 channels.

Our family of rugged MX interrogators is used extensively in civil engineering, marine, railways, roads, energy, geotechnical, industrial, security, medical, and many other commercial applications. This economy model is specifically useful for security, civil engineering, energy, process control, material qualification labs, and R&D programs. The industrial-grade design scales well for volume production.


Repeatability, accuracy, and dynamic range: The M4 Interrogator provides measurements across its wavelength scanning range of 40nm. Using US patented laser calibration technology, the instrument features +/- 2pm repeatability, +/-10pm accuracy, and 25dB dynamic range with automatic gain and threshold control adjustments. Manual settings option for thresholds and gain stages also included.    

Top reliability: The M4 Interrogator is based on a semiconductor tunable laser that has been deployed in large volume in various field applications and features the worlds lowest MTBF. The interrogator has no movable parts, no tunable filters, and no optical switches, which enables top reliability over the standard temperature range of -15C to +55C. The M4 is also available upon request with -40C to +85C rating. The M4 is suitable for use as an integral part of a very rugged and reliable sensing system.

Adaptive to more types of sensors: The integrated electronics and embedded software allow the user to quickly adapt the instruments performance parameters to fit many different sensor configurations. Designed to monitor many types of sensors from narrow bandwidth (100pm) FBGs used in accelerometers and pressure sensors, to wide bandwidth (3.0nm) FBGs used in bio-sensing. Hardware implementation of peak tracking algorithms for FBG sensors included. The laser output power is <4 dBm and performance is maintained even with 20dB optical power loss on each of the M4s four channels.

Systems and network-ready: High-speed data acquisition and on-board computer processing make the M4 easy to use and easy to transmit large volumes of data by network connection. The Ethernet port for high-speed data transfer is 100Mbit/s. Separate serial UART port available to change the M4 IP address.

Lowest Cost and High Quality: The M4 Interrogator is based on the companys solid-state instruments platform and it has been optimized to address applications demanding the lowest cost while maintaining the quality and reliability of a high-quality instrument. Also available in 8 and 16 channel configurations.

Note 1: FBGs from 100pm to 3.0nm BW@3dB (FWHM) are supported. Best performance results obtained using 250pm FBGs.

Note 2: Dynamic gain per channel (6 levels covering 25dB of gain) delivering >25dB optical power dynamic range (saturation – minimum detectable power levels) at 1kHz rate.

Applications include Security, Civil Engineering, Industrial, Energy, Material Qualification Labs, and Research Centers

Femto Sensing International undertakes a rigorous development process before product release. The company is also firmly committed to continuous improvements after release to ensure performance and reliability to the highest standards, hence, specifications are subject to update without notice.

Femto Sensing International, LLC / 3657 Peachtree Road, Suite 10A, Atlanta, GA, 30319, USA / T: +1 404 326 3469, E: sales@femtosensing.com, W: www.femtosensing.com 

Leave a Reply

Your email address will not be published. Required fields are marked *