High-speed transceiver parallel optics MT subassembly

 With the growth of global data volume, parallel optical technology is an important technical for the expansion of current data centers, and the optical transmission rate has continuously evolved from 10Gbps, 40Gbps, 100Gbps to 200Gbps, 400Gbps, and even 600Gbps, 800Gbps. At this year's OFC conference, a number of Chinese suppliers have successively demonstrated 800G rate optical modules, which means that 800G will enter a new era.

What is parallel optics? Parallel optical technology is a special optical communication technology that transmits and receives signals at both ends of the link. Parallel optical transceiver modules are usually used to achieve high-speed signal transmission at both ends. Parallel optical technology is a cost-effective solution for 4×50G, 8×50Gbps transmission.

In parallel optical signal transmission, the parallel optical modules at both ends of the link contain multiple transmitters and receivers. Multiple optical fibers are used to transmit and receive signals. The data rate of multiple-channels parallel transmission can support 40G to 100G per second. As shown in the figure, 8-bit data is simultaneously transmitted through parallel lines, so that the data transmission speed is greatly improved. Multimode parallel technology is mostly used for short-distance transmission of 100G and below.

 

Parallel optical modules rely more on high integration and small packaging to generate less heat than multiple discrete devices. MT (MPO) ferrules and optical subassemblies are one of the key components supporting parallel optical interconnects, which are used to connect internal optical lenses and external optical interfaces, and can be integrated into optical module boards. The small size and multi-channel of the MT ferrule makes it easy to use as an external optical interface in the parallel transmission.

Relying on high-density parallel optics design and manufacturing capabilities, as well as high-precision mold manufacturing and measurement technology capabilities, HYC now has the mass production capacity of high-speed transceiver optical subassemblies.

MT-Jumper

The ferrules of MT-jumper are available in 0° and 8° polishing angles. The length tolerance can be customized, and the minimum can meet ±0.15mm.

 

MT-2×Mini MT

Due to the compact internal structure of some optical modules, the traditional MT ferrule is bulky and may not be able to be inserted into the transceiver. Mini MT ferrules are the right devices to use in this small space connection, which are half the size of traditional MT ferrules.

 

MT-FA

MT-FA is a short fiber jumper composed of MT and fiber array. The end face angle of FA can be customized and it requires high precision. It is widely used in 100G PSM4 to connect to the external port.

 

About HYC Co., Ltd

With 22 years manufacturing experience of passive optical devices, HYC has three technical capabilities, passive optical devices chip packaging and coupling technology, precise mould/injection molding design and manufacture technology, and fiber array design and manufacture technology. HYC can provide one-stop customized services for passive devices design, R&D, manufacturing, with optical fiber connectors, patch cords, plc splitter, wdm, high-speed transceiver optical subassembly and mems optical switch production lines.

 OTDR is an Optical Time-domain Reflectometer. It is the main devices in optical fiber measurement. It uses to test detect problems that may exist in fiber links.

OTDR is widely used in carrier backbone networks. By analyzing the measurement curve, it can quickly detect the fault location of the optical fiber link and the fiber loss. The working principle is to use a laser light to send a higher power laser or light pulse to the test fiber. OTDR observes the power of the laser signal from each point on the fiber and records these results through a trace diagram. It can calculate the distance by recording the return time and transmission speed. 

In the PON (Passive Optical Network) network, especially the complex point-to-multipoint PON ODN (Optical Distribution Network) topology applications, rapid monitoring, and diagnosis of fiber fault locations is a challenging subject. At present, optical time-domain reflectometer (OTDR) tools are widely used for monitoring the fiber network. However, OTDR detection may not be so particularly sensitive to the attenuation of optical signals at the ends of some ODN branch fibers or ONU fibers. The application of FTTx terminal splitter to the main cable signal makes the traditional OTDR fiber optical detection techniques unable to achieve on-off detection. So a cost-effective and wavelength selective fiber optic reflector is a basic method of implementation of optical layer monitoring on the whole length of an FTTx network from the OLT to the ONT in real-time.

The working principle of the fiber optic reflector is mainly to use Fiber Bragg Grating (FBG) to reflect the test light pulse sent by OTDR with nearly 100% reflectivity. But the wavelength of normal passive optical network (PON) will pass with a small attenuation. The main purpose is to accurately calculate the return loss value of the reflected event at the end of each ONU branch by detecting whether the reflected OTDR test signal exists and the intensity of the optical signal. Therefore, it can easy to determine whether the optical link from the OLT side to the ONU side is normal. By detecting the reflected signal through OTDR, it can accurately grasp the fiber breakage, loss anomalies, fault location, and locate the error quickly.

The end-to-end OTDR measurement from the OLT to the ONT is usually difficult because the splitter brings high losses and complex networks. The application of optical fiber reflector is a cost-effective solution to help OTDR detection, and is the best way to realize real-time end-to-end (OLT to ONT) monitoring of optical networks in FTTx networks.

The optical fiber (FBG) reflector independently developed by HYC has the advantages of low insertion loss, high reflectivity, and convenient installation. It is widely used in PON network, OTDR testing, central computer room testing, FTTX and other fields. HYC offers customized pigtail or adapter type, such as LC, SC, APC/PC and so on.

HYC provides optical passive components OEM/ODM services. We welcome any inquiry for customized optical devices solutions for optical communication industry, including fiber optic connectors/adapters, WDM, PLC splitter, MEMS optical switch for data center, FTTx, Cloud Computing industry, 4G/5G networks .

Mechanical Optical Switch & MEMS Optical Switch

 In the optical fiber communication system, the optical switch (OS) is mainly used to realize the physical switching of optical signals or other logical operations in the optical path, and is mostly used in the optical cross-connect (OXC) technology as a key device for optical switching.

Optical switch is a multiport device. The port configurations include 2×2, 1×N, M×N. Optical switches have a wide range of applications in optical fiber communication systems. According to the realization technology can be classified as mechanical optical switch, thermo-optical switches, acoustic-optical switches, electro-optical switches, magneto-optical switches, liquid crystal optical switches and MEMS optical switches, etc. Mechanical optical switch and MEMS optical switch are the two widely used optical switches.

The working principle of the mechanical optical switch is to redirect the optical signal by physically moving the optical fiber with the aid of a mechanical device. By moving the prism or directional coupler, the light at the input end is directed to the desired output port. There are three main types of mechanical optical switches: one is to use prism to switch the optical path technology, the other is to use mirror switching technology, and the third is to switch the optical path by moving optical fibers.

Mechanical optical switch

The MEMS optical switch is based on a micro-electro-mechanical system, which uses an optical micro-mirror or an optical micro-mirror array to change the direction of the beam to switch the light path. The principle of the MEMS optical switch is very simple. When the light is exchanged, the angle of the MEMS micro mirror is moved or changed by the drive of electrostatic force or magnetic power, and the input light is switched to the different output terminals of the optical switch to realize the switching and on-off of the optical path. The schematic diagram is shown below:

The principle of mems optical switch

The principle of the 2×2 optical switch is shown in Fig. Four waveguides are aligned in four directions and a vertical MEMS mirror is aligned in 45° direction. When the mirror is not inserted into the optical path, optical beams from waveguides 1 and 2 are coupled to waveguides 3 and 4, respectively. The port connection is 1→3 & 2→4, which is the bar state. When the mirror is inserted into the optical path, optical beams from waveguides 1 and 2 are reflected by the mirror and then coupled to waveguides 4 and 3, respectively. The port connection is switched to 1→4 & 2→3, which is the cross state.

Principle of the 2×2 MEMS optical switch, left: bar state, right: cross state

MEMS optical switch

With the rapid development of optical communications, the status of optical interconnection and optical switching as optical network nodes is becoming more and more important, and the application of optical switches is becoming more and more extensive. MEMS optical switches have the advantages of compactness, fast switching speed, and easy expansion. At the same time, they have the low insertion loss, low crosstalk, low polarization sensitivity, high extinction ratio and high switching speed of waveguide switches, small size, and easy expansion of mechanical optical switches. The advantages of large-scale integration. It will be the mainstream direction of the development of high-capacity switching optical network switches.

HYC independently develops MEMS optical switch series products, with 1×2, 1×4, 1×N channel configuration, which can be expanded up to 1×48 channels, and has the advantages of low power consumption, integration, fast response speed, and cost reduction. Headquartered of HYC Co., Ltd is in Qingyuan Guangdong, and HYC has R&D centers in Wuhan and Shenzhen. It has more than 1,000 employees and has more than 20 years of OEM and ODM experience. It provides one-stop customization for the design, R&D and manufacturing of optical communication optical passive components. 

How to Choose High Quality Fiber Optic Adapter?

Optical fiber adapter is the connecting parts in the middle of optical fiber connectors. The fiber optic adapter can precisely connect the two end faces of the fiber so that the optical energy output from the transmitting fiber can be coupled to the receiving fiber. It is designed to join and align the connectors of two fiber optic patch cables.

With the widespread use of fiber optic adapters in fiber optic connections, there are a variety of optical fiber adapter to choose, to adapt to different environment installation requirements.  Common types of adapters are: LC adapter, FC adapter, SC adapter, ST adapter, E2000 adapter, MTP / MPO adapter.

With a number of different adapters available, how to pick the high quality fiber optic adapter may become a problem. In general, the following points should be considered when considering fiber optic adapters.

Flame retardant level of the adapter

UL 94, the Standard for Safety of Flammability of Plastic Materials for Parts in Devices and Appliances testing, is a plastics flammability standard released by Underwriters Laboratories of the United States. The standard determines the material’s tendency to either extinguish or spread the flame once the specimen has been ignited.

HB,V0, V1 and V2 are different flame retardant grades. Different grades has different fire resistance test methods and different test criteria. Flame retardant grades are gradually increased from HB, V-2 and V-1 to V-0. There is less optical fiber adapters on the market that can reach the UL94-V0 level. HYC’s LC Dual/Quad adapters complies with the UL94-V0 standard.

Insertion loss

Usually, insertion loss is required to be less than 0.2dB. If the insertion loss is too high, it will affect the transmission of light.

Repeatability

The adapter needs to be plugged and unplugged frequently, so the durability of the adapter is important. The normal standard needs to ensure that the number of plugging and unplugging can reach more than 500 times without affecting the insertion loss.

Operating temperature

-40℃ ~ 75℃ is a normal working range of the adapter. The operating temperature of this HYC LC adapter is -40℃~85℃.

Materials for adapter alignment sleeve

The alignment sleeve is the most important component of the fiber adapter, which is generally made of metal or ceramic.The fiber adapter made of ceramic will have a relatively good effect. Because the crystal structure of ceramic is hard and not easy to be deformed, it can achieve fast alignment and high-precision optical fiber end face connection.

Generally speaking, the above five points should be taken into account, when considering a fiber optic adapter. There are still some other factors affecting the quality, such as tensile strength and compliance standards,etc. Fiber optic adapters are widely used in communication equipment rooms, FTTH fiber-to-the-home, local area networks, fiber-optic communication systems, fiber-optic connection transmission equipment,defense operations equipment, and so on. Although the fiber optic adapters are small, its quality directly affects the entire fiber link. It should be rigorous and comprehensive while choosing the fiber optic adapters.

Article from HYC Blog

WDM for Optical Fiber Capacity Expansion

WDM (Wavelength Division Multiplexing) provides an easy-to-implement solution for long-distance transmission of high-speed and large-capacity information, which would increase transmission capacity of the communication network.

The traditional optical transmission method is that one fiber can only transmit one wavelength signal in a single time, while WDM transmits several wavelengths of light simultaneously over a single optical fiber. WDM mainly realizes wavelength multiplexing and demultiplexing through a combiner and a splitter. At the transmitting end, signals of multiple wavelengths are multiplexed together by a combiner and coupled to the one same optical fiber for transmission; At the receiving end, the optical signals of different wavelengths are separated by a splitter to restore the original signal. The wavelength division multiplexer has both multiplexing and demultiplexing functions. In long-distance transmission, an optical amplifier is usually used to enhance the optical singal transmission to aviod minimum attenuation.

The index of characteristics of WDM includes insertion loss, return loss, polarization loss, channel isolation, operating temperature, etc. The two most important characteristics to be measured are insertion loss and isolation.Insertion loss refers to the attenuation caused by the insertion of WDM filter into the optical transmission system. The lower the insertion loss, the better.The isolation refers to the degree to which one channel signal interferes with another channel, and the higher the degree of isolation, the better.

Features:

Multiply the transmission capacity. The characteristics of WDM enable it to make full use of the bandwidth resources of the fiber, so that the transmission capacity of one fiber is increased by multiple times than that of a single wavelength. With a channel rate of 10 Gbit/s or 2.5 Gbit/s, the number of WDM channels can be can be up to more than 32, ensuring that the transmission capacity can reach 300~400Gbit/s.

Good compatibility. WDM has good compatibility with different signals. When transmitting signals with different properties such as image, data and voice, each wavelength is independent from each other and does not interfere with each other to ensure the transparency of transmission.

On the basis of not changing the existing basic network architecture, WDM allows you to expand capacity without replacing your existing infrastructure and with minimal, if any, service interruption.