FAZT I4G Interrogator


Technical Paper 1

Technical Paper 2

Technical Paper 3


The FAZT I4G optical sensing instrument is a revolutionary new breed of interrogator. Featuring 4 monitoring channels the FAZT-I4G is the company’s flagship model instrument. Enclosed in a field deployable stainless-steel casing, the instrument provides peak detection for up to 30 Fiber Bragg Gratings (FBG) based sensors on each of its 4 channels. The instrument can be operated in full spectrum and sensor peak detection modes. The FAZT I4G is optimized for both static and dynamic measurements.

Our family of rugged FAZ Technology interrogators is used extensively in marine, railways, roads, energy, civil, geotechnical, industrial, security, medical, and many other commercial applications. It is also the instrument of choice for Research and Development Centers that seek to achieve ultimate precision and repeatability measurements. The industrial grade design scales well in volume production.


Ultimate precision, repeatability, and accuracy: The FAZT I4G Interrogator returns measurements in 1pm steps across its wavelength range. Using patented FAZ Technology scan-by-scan calibration, the instrument features ultimate 0.1pm absolute precision, superb repeatability of 50fm max, and absolute accuracy of 1pm (Gas Cell and MZI referenced in closed PM circuit). Ultimate measurements require tight control of all three calibration parameters: precision, accuracy and repeatability.

Top reliability: The FAZT I4G Interrogator is based on a semiconductor tunable laser that has no movable parts, no tunable filters, and no opto-mechanical switches, which delivers top reliability over a broad temperature range to form 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 instrument’s performance parameters to fit many different sensor configurations. Designed to monitor with ultimate precision more types of sensors than any other instrument, from narrow bandwidth (40-100pm) FBGs used in high-sensitivity accelerometers, pressure sensors, hydrophones, and microphones, to wide bandwidth (1.5nm) FBGs used in bio-sensing. Hardware implementation of peak tracking algorithms for FBG sensors including programmable gain per sensor, width/height thresholds, and distance to sensor setting for accuracy at long distance. The laser output power (typically ~2 dBm depending on configuration) and high sensitivity receiver yield exceptional optical dynamic range performance over long distances.

Systems and network ready: High speed data acquisition and on-board computer processing make the FAZT I4G easy to use and easy to transmit large volumes of data by network connection. Trigger Input support enabling synchronization of multiple optical and electrical sensor systems. The Ethernet port for high speed data transfer is 100Mbit/s, with all interrogator settings programmable over a REST interface. NTP (<10ms timestamps) Time accuracy with optional GPS time (<10µs timestamps).