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Novel low-cost camera-based pulsed and modulated continuous wave laser detection

A novel, low-cost, camera-based method of detecting a single nanosecond laser pulse and kHz modulated continuous wave and pulsed lasers has been developed at DSTL. The detector uses a simple optical modification to a standard rolling shutter colour camera combined with image processing techniques to distinguish lasers from other illumination sources and extract a lasers wavelength and pulse repetition frequency. In addition the detector is also capable of detecting a single nanosecond laser pulse at any given time. Such a detector has applications in free-space optical communications, as a low cost broadband method of extracting information from multiple sources, and as a detector of laser range finders. A low cost prototype (≈£600) has been developed using entirely off-the-shelf components and assessed in laboratory conditions, with the ability to measure laser wavelengths to ±5nm and pulse repetition frequencies to within ±5%. In the laboratory the prototype was also able to detect each of the 1000 pulses generated by a 10Hz 10ns 532nm pulsed laser, as well as 100 pulses sent at random intervals, highlighting its capability to detect a ns pulse at any given time. The prototype was taken to the Moonraker NATO SET-249 field trial, where it was able to measure the pulse repetition frequency of a modulated continuous wave laser source to within ±5% at a distance of 660m. This novel technology offers a low cost method of detecting lasers and extracting their pulse repetition frequencies, with a wide field of view and high spatial resolution.