Laser Information

The word LASER is an acronym. It stands for Light Amplification by the Stimulated Emission of Radiation.

By "radiation", however, the acronym refers to a radiant vibration, not an emission of radioactive particles. In other words, the emissions of lasers are in the form of light, and the frequencies can range anywhere from infra-red to ultraviolet, police laser guns are in the infra red range.

Police laser guns are the preferred method now for mobile speedtraps, radar was reasonably successful but soon became obsolete with the advent of the laser gun which is faster and more accurate. Readings can be taken in a fraction of a second. It needs a flat relective surface such as a number plate or even a headlight. Most current models must be calibrated once a year by the manufacturer and also at the start and end of each shift by the officer with a calibrated speedometer. The distance to the target must be a minimum of 10 times the height from the road.
Popular in Kent, Manchester and Wales forces, but fast becoming the most popular form of mobile trap across the country. The device can be switched for oncoming or receding vehicles. On an interesting note the Lti 20-20 has been banned in certain American states as the shake effect when using a heavy hand held device can affect it's accuracy. The laser gun can pinpoint a target in a lane of traffic, it takes less than half a second to get a reading wheras a radar can take 2-3 seconds. It can't be used from behind glass, requires a very steady hand so when used over 400 yards they need to be tripod mounted for stability, and at 1000 feet the beam is 3 feet wide, at 1 and 1/2 miles the beam is 2 lanes wide.

The Road Angel GPS Speedtrap Detector now has a Laser Detector for mobile speedtraps. Have a look at the Road Angel Plus.


There are four main classiffications of laser and these have been created to show their effect or damage on biological material and hence their strength.

  • Class I - These lasers are not known to be hazardous to biological material.
  • Class I.A. - Supermarket laser scanners as well as others fall into this category and are "not intended for viewing". The maximum power limit is 4 mW.
  • Class II - A low-power visible laser that can emit above Class I levels but with a maximum radiant power of 1 mW. The "human aversion reaction to bright light" should protect somebody from this amount of light radiation, at least that is the theory.
  • Class IIIA - An intermediate-power laser between 1-5 mW, which may be hazardous when viewing. Laser pointers fall into this class.
  • Class IIIB - Lasers of moderate power.
  • Class IV - High-power lasers (cw: 500 mW, pulsed: 10 J/cm2 or the diffuse reflection limit), whether direct or diffused these are hazardous, these can cause combustion and are a biological hazard so need to come under significant control and regulations.

The word LASER is an acronym. It stands for Light Amplification by the Stimulated Emission of Radiation. By "radiation", however, the acronym refers to a radiant vibration, not an emission of radioactive particles. In other words, the emissions of lasers are in the form of light, and the frequencies can range anywhere from infra-red to ultraviolet.

Police laser guns are Class I and represent no danger to the passing motorist. They use a Gallium Arsenide Diode to create the laser.

Short Range

This highlights the difficulties of short range detection. The beam is very narrow and with a single sensor it is not possible to cover both scenarios.

Long Range

At long range it is not possible to choose which part of the vehicle they want to target. On some Laser Guns the sight is bigger than the vehicle. Wherever the detector is fitted it is possible to trigger it.

Following a vehicle being targeted

At short range it is difficult to detect, but if the vehicle in front is targeted from long to medium range it is possible to detect as long as the sensor is fitted the front windscreen.

Rear Detection

When the vehicle is targeted from the rear, the laser signal will pass thorough the rear windowscreen and trigger the laser detector as long as no obstructions are in the way.

 

For a Laser Remote Control take a look at the LT400 or for a Laser Parking Sensor have a look at the Laser Pro Park.