Many optical networks integrate optical switches into their design. Opto-mechanical switches redirect optical signals from one port to another by moving a fibre tube assembly or an optical component, such as a mirror or prism. There are many different types of optical switches incorporated into networks. In practice, most optical switches are still operated mechanically and controlled by an electronic control circuit. Speed is a crucial parameter in network applications, since a high-speed data transmission of tenths of milliseconds is required. In the near future, dynamic optical routing will require much faster switching speeds. More technology exists for optical switches than any other functional component within the optical network. Researchers are developing optical switches to increase the number of outputs, and to reduce size, cost, and switching time. Presently, optical switches include many types, for example: opto-mechanical switches, thermo-optic switches, electro-optic switches, micro-electro-mechanical switches (MEMS), and micro-opto-mechanical switches (MOMS). New types of optical switches are in the research and development stages.