Optical MEMS (Micro-Electro-Mechanical Systems) is the integration of mechanical elements, sensors, actuators, and electronics on a common silicon substrate through microfabrication technology. And Optical MEMS has created a new fabrication paradigm for optical devices and systems. Using tools developed for the integrated-circuits industry, Optical MEMS brings unprecedented levels of miniaturization and integration to optical communication systems. Today, the capacity of optical communication networks is limited by the switches that are electronic in their core. Optical MEMS is transforming the telecommunications infrastructure by providing all-optical switches that enable high-capacity networks. Optical MEMS devices are driving the trend toward all-optical telecommunication networks. With the ability to directly manipulate an optical signal, MEMS have several applications that eliminate unnecessary optical-electrical-optical (O-E-O) conversions. In optical communication, electrical components such as inductors and tunable capacitors can be improved significantly compared to their integrated counterparts if they are made using optical MEMS technology. With the integration of such components, the performance of communication circuits will improve, while the total circuit area, power consumption and cost will be reduced. In addition, the mechanical switch, as developed by several research groups, is a key component with huge potential in various microwave circuits. Optical MEMS technology is currently used in low- or medium-volume applications. There are also some of the obstacles preventing its wider adoption. Such as a mechanism giving smaller organizations responsive and affordable access to optical MEMS fabrication. And the packaging of optical MEMS devices and systems needs to improve considerably from its current primitive state. Currently the designer of an optical MEMS device requires a high level of fabrication knowledge in order to create a successful design. This paper presents the technology of optical MEMS and the application of this technology in the optical communication.