Programme to to design, develop and manufacture distributed feedback fibre lasers which will be used in acoustic sensing application
Optical components supplier SPI has been awarded a contract by Qinetiq (the UK science and technology research company formed from the larger part of the Defence Evaluation and Research Agency) to design, develop and manufacture distributed feedback fibre lasers (DFBs).
It is planned that the lasers are to be used in an application for sensing acoustic signals.
DFB fibre lasers are finding important applications in a wide range of functions such as in hydrophony, seismology, ocean bed surveying, multiphase flow measurements, and sub-sea oil and gas pipeline monitoring.
Furthermore, when DFBs are packaged as sources, their narrow line width makes them ideal for such sensing applications as Lidar and Lidar arrays.
DFB fibre laser technology is very new and SPI is one of only a handful of companies that have announced commercially available products and specialised contract services in the specialty fibre area.
The secret of the laser, which is built into the optical fibre itself, lies in the associated Fibre Bragg Grating (FBG), which determines the lasing wavelength very precisely.
When suitably packaged for sensing, the lasing wavelength of a DFB is very responsive to the pressure changes in its environment.
Pressure fluctuations caused by acoustic signals produce changes in the length of the Bragg grating.
These give rise to infinitesimal shifts in the lasing wavelength that can be detected and processed to recover the acoustic signal.
DFB acoustic sensing technology has many distinct advantages over existing solutions, in terms of size, weight, reliability and cost.
In addition, the ability to use the devices in multi-channel arrays is of particular interest to Qinetiq.
Using the DFBs in such an array enables a precise range and bearing of an acoustic source to be determined.
SPI's proven ability to multiplex the devices using existing DWDM technology was a key factor in Qinetiq's decision to award the contract.
Stuart Woods, SPI's director of business development, commented, "SPI's common technology platform is enabling us to move forward rapidly with the development of DFB fibre lasers that are having a dramatic impact on the cost of ownership, footprint and maintenance overheads of many applications in military, analytical and industrial markets.
Our strength in disruptive power solutions has a lot to offer the new generation of sensing systems, not only in the sensing element itself, but also in multi-wavelength ultra-low-noise laser arrays for interrogating massive remote arrays."
