Optical telecommunication systems require a variety of devices for generating, transmitting, amplifying, filtering, switching, detecting and otherwise processing optical signals. In the optical communication, an optical fiber forms a waveguide for the optical signal. There is a need to switch the optical signal from a first optical waveguide to a second optical waveguide. Efficient switching of optical signals between individual fibers is necessary in most optical processing systems or networks to achieve the desired routing of the signals. In fiber optic networks, light signals are transmitted along optical fibers to transfer information from one location to another. Optical switches are used to selectively couple light from an input fiber to an output fiber. Fiber optic switching is an important component in any telecommunication system. These systems use switches to establish communication channels among two or more of their interfaces. Fiber optic switches have been developed for selectively switching optical signals from one fiber to another fiber. An optical fiber switch is capable of optically connecting, or aligning, any one of a first group of optical fibers with any one of a second group of optical fibers, or vice versa, enabling an optical signal to propagate through the optical interface junction from one fiber to the other. Switching for these fibers has previously been achieved with optoelectronic devices. Optical fibers are coupled with circuitry that permits the switching to be done electrically, and then the electrical signals are converted back to optical signals for further transmission. Optical switching technology's main advantage is to route optical data signals without conversion to electrical signals, resulting in the independence of data rate and data protocol. In general a pure optical switch routes beams of light with encoded data from one or more input optical fibers to a choice of two or more output optical fibers. A variety of optical switch technologies have been developed for telecommunication applications such as network protection, network restoration, equipment and device redundancy, performance monitoring, research and development, and spectral interferometry. Other applications for optical switches include medical, aerospace, national defense, and other manufacturing and industrial industries.

The fiber optic switch is a basic building block for many optical applications such as routing in fiber communications networks, photonic signal processing, distributed optical sensing, and optical controls. Optical switches use various mechanisms to switch light beams from an input to a selected output. The optic switches are usually classified as mechanical type and non-mechanical type. The mechanical type optic switch realizes switching operation between two or more outputs by moving optic fibers or optic elements with mechanical or electromagnetic means. In general, mechanical or electromechanical fiber optic switches can be classified in two basic types, i.e., moving beam and moving fiber. Moving beam switches include optical collimating lenses which expand the beam of light from the fibers, and then by way of movement of prisms or mirrors, the expanded beam is redirected as required in the switching process. Moving fiber switches involves the actual physical movement of one or more of the fibers to specific positions to accomplish the transmission of the beam of light from one fiber end to another under selected switching conditions. The mechanical optical switch comprises a movable optical fiber which can be elastically deformed and two fixed optical fibers, an open end of the movable optical fiber facing to open ends of the fixed optical fibers via an optical gap, and switches the optical path by displacing the open end of the movable optical fiber with respect to the open ends of the fixed optical fibers. Power consumption in optical switches must be minimized because optical switches are usually in operation at all times and therefore any unnecessary power consumption is a significant waste of resources. Fiber optic switch design and optics design are integrally related because fabrication methods are deeply influenced by the size, shape, and structure of the optics, which factors ultimately determine what methods are feasible.

Optical switches are required to be extremely small to allow many channels to be switched in a relatively small amount of space. The newest type of optical switches fit into the general category of micro-electromechanical systems (MEMS). Modern technology has enabled microelectromechanical systems (MEMS) to be fabricated on semiconductor substrates, typically silicon substrates. These MEMS typically have sizes in the order of microns and may be integrated with other electrical circuits on a common substrate. MEMS optical switches mainly have three design configurations: piezoelectric, electrostatic and electromagnetic. These switches utilize micro-mirrors to switch or reflect an optical channel or signal from one location to another depending on the relative angle of the micro-mirror. Piezoelectric switches utilize piezoelectric materials to change shape proportionally to how much electrical voltage is applied to them. The mirror is then attached to the piezoelectric material, which can be manipulated by applying varying degrees of electrical voltage. Electrostatic switches are currently the most popular form of MEMS optical switches. These switches utilize the small electrostatic force produced by a diamagnetic material when an electrical field is induced upon it. Electromagnetic optical switches tend to utilize ferromagnetic materials to rotate and manipulate the angle of the mirror. Ferromagnetic materials are easily magnetized and are capable of producing large forces. MEMS optical switches are used in a variety of applications such as switching light waves between optical waveguides, such as fiber optical waveguides.