Precision optics cover all manner of devices that are used to manipulate or control light. These components either use electrical or electronic means to manipulate light, such as lasers, diodes, photomultipliers and optoelectronic sensors, or they can force the manipulation via material means. This second grouping includes items such as lenses, filters, beamsplitters, mirrors, diffusers, plates, prisms, and windows. A subgroup of this category is fiber optics. This grouping includes all products that are used to transmit light via transparent glass or plastic fibers. Items within the optics and optical components category fall into four loose families: light sources, optical components, optoelectronics, and fiber optics.