Laser accessories enhance the capabilities of lasers for a variety of applications. They can range from simple laser-aiming devices to more complex ones such as beam-splitters and frequency-doublers. Some of the most common laser accessories include lenses, mirrors, and filters. Lenses can be used to change the size and shape of the laser beam, while mirrors can be used to redirect the beam onto different objects or surfaces. Filters can be used to reduce the brightness of the laser beam or to change its color. Additionally, closed-loop systems can be used to improve the accuracy of laser cut components.