Laser weapons utilize a coherent photon beam to deliver intense energy to a target with the intent of causing damage through heat and ablation. Due to the threat of reflected energy causing damage to eyes, most Fringe denizens have undergone filtered lens replacement. The cheap, effective, replacement lens can filter light over a certain intensity, so that personal laser arms don't damage the eyesight of everyone nearby when discharged. There is a common misconception that mirrored or reflective surfaces provide immunity to laser arms. While highly reflective surfaces do offer some limited protection, the ablation effects of intense laser energy will make such tactics largely ineffective. The best means of personal defense from laser weaponry is angled personal armor, so that the amount of surface area that the beam can effect is minimized, but armor made from heat-resistant materials like ferozium work best.
Currently probably the most advanced form of weaponry, lasers as they are in the current time-period exist only in gun form, as attempt to make a closed-circuit style sword of sorts to contain a beam between two focal points has resulted in overheating, melting, and explosions. In gun form though, lasers are utilized quite efficiently, though are among the most expensive sorts of ranged weapon to exist that is mass produced. Using a compound that reacts by emitting bursts of UV and gamma rays when burned in the receiver of the weapon upon extraction from a canister serving as a magazine, the compound’s emissions are focused by an array of mirrors and lenses typically composed of various forms of crystals capable of magnifying the effects of the resulting beam. These beams are used, quite simply, to poke holes in things with their extreme heat and precision, and while laser ‘beam’ weapons are less used due to the risk of overheating or exploding, laser ‘burst’, or repeating weapons are more than efficient at their task provided they are not being fired at ferozium or violium.