PLC is more known in the field of electronic technology. It is the acronym of the terminology ‘programmable logic controller’. However, in the field of optical communication, PLC is the acronym of another terminology, i.e. ‘planar lightwave circuit’, which is variable optical waveguide structures fabricated with integrated optics technologies. PLC technologies can implement functional devices as directional coupler (DC), Y-branch splitter, multimode interferometer (MMI), arrayed waveguide grating (AWG), optical interleaver (ITL), Mach-Zehnder (MZ) electro-optical modulator, thermo-optical variable optical attenuator (TO-VOA), thermo-optical switch (TO-SW), etc.Continue reading
To understand the types of optical fibers, optical cables, jumpers, connectors, and adapters, you first need to know the relationship between these products.Continue reading
This article will include these subject.
What does WDM stand for?
The basic structure of WDM system
Advantages of WDM technology
What does Mux and Demux stand for?
The difference between WDM and optical splitter
The indicators that affect the WDM devices
How to understand the O, E, S, C, L, U band
What does CWDM stand for vs. DWDM, FWDM, LWDM, MWDM?
What does WDM stand for?
Wavelength Division Multiplexing(WDM) is one of the most common way of using wavelengths to increase bandwidth by multiplexing various optical carrier signals onto a single optical fiber. It combines a series of optical carrier signals with different wavelengths carrying various information and coupled to the same optical fiber for transmission at the transmitting end. At the receiving end, optical signals of various wavelengths are separated by a demultiplexer. This technique of simultaneously transmitting two or many different wavelengths in the same fiber is called wavelength division multiplexing, or WDM.
With the development of ultra-high-speed and integrated optical communications, optical transceiver modules are also expected to adopt smaller and more integrated solutions, which have high demand for parallel high-speed optical subassembly. Due to the high cost caused by strict material usage and processing technology, the optical fiber array has not been widely used for 10G transmission. With the rapid advance of 400G and 800G high-speed transmission, FA with high-density packaging can be said to be a more ideal solution.
Optical fiber arrays are most commonly used in the packaging of planar optical waveguide splitters (PLC) and arrayed waveguide gratings (AWG). With the explosive growth of data flow, the demand for optical fiber arrays in data centers and 5G commercial applications is growing rapidly, and FA has become more and more widely used in MEMS systems, sensors, silicon photonics and other fields.Continue reading
This article will including:
What is optical switch?
Working principle of MEMS optical switch
Structure of MEMS fiber optic switch
MEMS optical switch VS Mechanical optical switch
The advantages of MEMS switch
The applications of MEMS fiber optic switch
The MEMS based optical switch in AONContinue reading
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.
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.
In the Passive Optical Devices for 5G Application(Part II), we introduce Tunable Optical Filter (TOF) for Coherent Receiving, Optical Performance Monitoring (OPM) Module, Optical Channel Monitoring (OCM) Module. This article will show you other important passive optical devices for 5G application.
Dynamic Gain Equalization (DGE) Filter
For the complicated fiber links transmitting DWDM signals, OPM and OCM just provide solutions for monitoring of OSNR and channels. However, the DWDM signals need to be equalized before they leave each ROADM node or relay station. In the ROADM-based optical network, the power levels of the DWDM channels are always changing. Thus DGE is required to provide dynamic equalization of the DWDM channels, which is different from the fixed GFF (Gain Flattening Filter) for an EDFA.
With the rise of 5G technologies and massive deployment of 5G base stations, wireless access of terminals with high speed and large capacity is realized. Meanwhile, the traffic in optical fiber network increases rapidly. It is predicted that the current optical fiber network will become the bottleneck of information exchange in the future 12-18 months. The upgrading of optical fiber network is urgent. The representative trend is that the technologies for long-haul network (LHN) will be sunk to metropolitan area network (MAN), including DWDM (Dense Wavelength Division Multiplexing), ROADM (Reconfigurable Optical Add-Drop Multiplexer) and coherent receiving techniques. This paper discusses some of the passive optical devices for the coming 5G applications.
Tunable Optical Filter (TOF) for Coherent Receiving
In DWDM optical network, tunable optical filter (TOF), as one of the most important dynamic optical devices, is used to realize such functions as channel selection, optical performance monitoring (OPM) and optical channel monitoring (OCM) in the wavelength domain. The requirements of optical network for TOF include low loss, wide tuning range and good filtering characteristics.