Laser Detection System Technology

While most ordnance is now laserguided, there is still much work to be done on the defensive detection of laser designators. Hence the growing need for advanced laser-warning systems (LWS). While multiple techniques can be used to detect and triangulate the position of an incident laser designator, one of the current front-runners in the race for positional accuracy is Excelitas’ High Angular Resolution Laser Irradiance Detector (HARLID™).

Figure 1. LWS-equipped helicopter responding with flares and smoke screen after AOA detection of incident laser beam designators.
HARLID is able to precisely pinpoint incoming threats in real-time allowing for the quasi-instantaneous deployment of semi- and automated-threat response mechanisms such as smoke screens or flares (Figure 1). Its unique digitalencoding of the angle of arrival (AOA) of well-collimated laser designators operating between 500 and 1650nm has received positive feedback from the men and women who depend on its operation on the front-line of modern-day armed conflicts.

How Does It Work?

Figure 2. HARLID™ TO-8 can dimensions (Gray code mask not shown, dimensions in inches).
Close-proximity combat remains the last resort for most strategic missions. Through the use of laser-guided artillery, soldiers can gain the upper hand in a combat situation while remaining, hopefully, out of harm’s way. The days of dropping large loads of “dumb” ordnance with the hope of inflicting sufficient damage to the target are over. Over the years, the LWS and Laser Range Finder (LRF) markets have thus taken the lion’s share of the military electro-optical (EO) market.

The HARLID™ effectively encodes digitally the AOA of incident laser beams from laser guidance systems, designators, beam riders and range finders; furthermore it enables the detection of “friend-or-foe” of said laser designator through Pulse Repetition Frequency (PRF) detection and laser technology used through coarse wavelength band detection.

Figure 3. HARLID™ Silicon and InGaAs sandwich-detector configuration.
Originally conceptualized by the Defence R&D Canada – Valcartier team and designed for manufacturing by Excelitas Canada Inc, the HARLID™ is often described as a low-weight, lowpower, self-contained LWS building block. Enclosed within a custom 20- pin TO-8 can (Figure 2), it can detect light from 500 to 1650nm using a Silicon-InGaAs sandwich-chip design (Figure 3).