A laser of many colors
The laser Fence team at Liverpool’s John Moors University has completed its launch of a “white” laser source NKT Photonics supercontinuum. The laser source will be used for the development of LaserFence systems of different colors for use in field trials.
The notion of lasers is that they are a monochromatic light source (single color). A green laser of 532nm wavelength is typically used in avian deterrence systems. This wavelength seems brighter for the human eye, but the sight of the animal can be remarkably different. So the project wants to evaluate different colors to create a laser fence.
But the supercontinuous is a real white light laser. This is not achieved by mixing red, green and blue lasers as it would be used in light shows and projection systems. This is achieved by producing ultrashort laser light pulses (PS) in a special optical fiber that is internally structured. This optical fiber “stretches” the laser of its original monochrome color in a broad spectrum from ultraviolet to infrared and is visible as a white laser beam.
The laser then passes into a filter box. This allows the light to be filtered to a specific wavelength, or color, and bandwidth, from the visible spectrum ranging from deep violet to deep red. Then this beam would be supplied by an optical fiber expander and beam to create a variable and programmable color LaserFence.
Fig. 1 back of supercontinuous Laser, programmable filter to the right and beam expander in foreground.
Fig. 2 laser beam supercontinuous to 532nm (green)
Fig. 3 different color wavelengths of the supercontinuous laser (note that the camera is saturated with intensity in the center of the beam).
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