The advent and development of fiber optic communication technology has brought a revolutionary change to the communications industry. Nowadays in the world, about 85% of communication services via optical fiber transmission, long haul network and local relay network has been widely using fiber optics.
Dense Wavelength Division Multiplexing (DWDM) technology development and maturation has opened up a vast space for the full application of the bandwidth and capacity of optical fiber transmission. With a high rate, large bandwidth obvious advantage, DWDM optical communication network has become the development of communication network trend. Especially in recent years, an IP-based Internet business explosive growth, this growth trend has not only changed the relationship between the IP network layer and the underlying transport network, and the networking of the entire network, the node design, management and control new requirements.
An intelligent network architecture – Automatic Switched Optical Network (ASON) has become a research hotspot of today’s systems. Its core node optical cross-connect (OXC). Constitute dynamic wavelength routing and optical network flexible and effective management can be realized by the OXC equipment. OXC technology is one of the key technologies increasingly complex DWDM network, optical switch for switching the optical path of functional devices, is a key part of the OXC. Optical switch matrix is the core part of the OXC, it can achieve dynamic optical path management, optical network fault protection, wavelength dynamic allocation function, the solution to the current complex network of wavelength contention and improve the wavelength reuse, flexible configuration of the network are There is of great significance.
Optical switch is not only the core device in OXC, but also widely used in the following areas.
(1) Optical network protection switching system, the actual optical transmission system have left spare fibers when working channel transmission interruption or performance degradation to a certain extent, the main signal light switch automatically go to standby fiber system transmission, so that the receiving end received normal signal and feeling less than the network has a fault, the network nodes connected in a ring to further improve the survivability of the network.
(2) Real-time network performance monitoring system, remote fiber test points, 1 × N multi-channel optical switch, a plurality of optical fibers connected to the Optical Time Domain Reflectometer, real-time network monitoring, computer-controlled optical switch switching sequence and time to achieve the detection of all fiber, and test results are returned to the network control center, once found a road problems, can be processed directly in the network management center.
(3) The light switch is also used in optical fiber communication device testing system and metropolitan area networks, the poor access network/multiplexing and switching equipment. The introduction of the light switch in the future all-optical networks more flexible, intelligent, survivability. Optical switching technology has become the key to future optical networking, optical switching technology plays an increasingly important role in the field of communication, automatic control.
In many types of optical switches, MEMS optical switch is considered most likely to become the mainstream of the optical switch device. In this paper, an overview of the basis of the principle characteristics of a variety of optical switch on, the focus of several major MEMS optical switch, and outlined their structure and performance characteristics.