A laser jammer is a device typically used by drivers to prevent law enforcement officers from obtaining speed readings using a laser gun. Laser jammers are not to be confused with radar jammers.
Because these jammers are for laser and not radar, US federal laws prohibiting the use of radar jammers do not apply to these devices. However, several states have one or more laws that specifically prohibit the use of laser jammers, including: California, Colorado, Illinois, Minnesota, Oklahoma, South Carolina, Tennessee, and Alaska. New York and Texas are currently trying to introduce legislation banning the use of laser jammers.[1]
Laser jammers for civilian use have evolved greatly in the past 15+ years. Different Lidar guns have different pulse rates and algorithms used to defeat laser jammers and/or detect them. The first laser jammer ever produced was by K40 Electronics in 1996, known as the K40 Laser Defuser. Next came the Lidatek LE-10 Laser Echo by Lidatek LLC, then the Blinder M06 HP by Blinder International out of Denmark, then the Blinder M10 Twin, then the LE-20 to LE-30. Blinder remade the M10 Twin into the smarter M20 X-treme series. Laser diode based jammers came out in 2006, known as the Anti-Laser, Laser Pro Park, and Laser Interceptor.
Laser jammers have been tested by Guys of LIDAR to be quite effective depending on the model of laser gun and jammer used in the "2008 Laser Jammer Shootout". http://www.guysoflidar.com/july-2008/laser-jammer-test.html. Retrieved 2011-11-04. Of particular note the "Laser Interceptor" device jammed nearly every gun tested under multiple scenarios. The "Traffipatrol XR" gun was still able to punch through the Laser Interceptor in testing, but only at a significantly reduced range of 80-600 feet, versus 2000 feet easily possible without a jammer.