Evolution of Optical Transmission Technology in Data Center With the popularization and application of mobile Internet, data center has developed rapidly and become an important infrastructure in the information society. The data center consists of a large number of servers. High speed and large capacity data transmission and exchange are needed between servers. The traditional cable transmission cannot meet the speed requirements. Optical fiber transmission technology has entered the data center since 2010, and has become the mainstream transmission technology.
Distributed optical fiber sensing technology Optical fiber sensing technology is a new type of sensing technology that developed rapidly with the development of optical fiber communication technology in the 1970s. It uses light waves as a carrier and optical fiber as a medium to sense and transmit external measured signals. Compared with conventional sensors, optical fiber sensors have many advantages such as high measurement sensitivity, anti-electromagnetic interference, anti-radiation, high pressure resistance, corrosion resistance, small size, light weight, and adaptation to harsh environments. The optical fiber component itself is both a detection element and a transmission element , which can connect many optical fiber sensing units on the optical fiber trunk to form a large-scale remote sensing system for distributed monitoring and measurement.
Introduction In recent years, the integrated optical passive devices are smaller in size and more mature in technology, occupying a considerable part of the market share. As one of the key devices of optical communication, erbium-doped fiber amplifier (EDFA) has become the technical focus of competition among many manufacturers due to its integration, miniaturization, multi-function and low cost. The integration of hybrid optical passive devices is not to use integrated technology to make devices, but to integrate separate devices together. The above competitive advantages of EDFA can be realized by integrating optical isolator, wavelength division multiplexing (WDM) devices, optical circulator and test access port (TAP) splitter into a hybrid device. At the same time, the manufacturing process of hybrid optical passive devices is also one of the key factors to realize the competitive advantage of the above-mentioned EDFA technology.
With the rapid development of optical fiber, the traditional communication devices with electricity as the core is hardly to meet the needs of high-speed and large-capacity optical communication network. MEMS optical switch has become one of the important devices in all optical communication network due to its small size, easy integration and large capacity.
MEMS optical switch is based on Micro-Electro-Mechanical System(MEMS) technology, using the micromirrors to control and switch the optical path. Its function is shown in the following figure:
Fiber optic connectors are the most basic optical passive components for optical fiber communication systems. The basic specification requirements for them are low insertion loss (IL) and high return loss (RL), i.e. low back reflection (BR). However, as the most widely employed components, low cost and easy connection are equal important as the specifications.
Alignment of Optical Fibers The core size of the single mode fiber (SMF) is about 8~10μm. The two connected fibers must be precisely aligned to ensure low loss. Fig.1 shows how much the lateral offset between two optical fibers influence the IL. The curve is exponential. A small lateral offset such as 2.4μm will introduce IL of 1dB. Thus the lateral offset between the two fibers must be kept <0.5μm for SMF fiber optic connectors.