Category Archives: Optical Switch

Core Switch & Edge Switch: How to Make a Decision?

When considering buying a network switch for your small business, you need to ask yourself a few questions: How many devices will the switch need to support? What kinds of devices will I be connecting? Has our network grown to the point where we need a switch with more advanced management capabilities? And here is an important decision you are going to make: whether core switch or edge switch for your network.

What Is A Core Switch?

A core switch, is also known as a backbone switch. It is a high-capacity switch generally positioned within the backbone or physical core of a network. Core switches serve as the gateway to a wide area network (WAN) or the Internet—they provide the final aggregation point for the network and allow multiple aggregation modules to work together. You use it to connect to servers, your Internet service provider (ISP) via a router, and to aggregate all switches that your company uses to connect crucial pieces of equipment that your company can’t afford to lose to downtime. As a result, your core switch should always be a fast, full-featured managed switch.

48 ports managed switch as core switch

What Is An Edge Switch?

An edge switch also is called an access node or a service node. It is a switch located at the meeting point of two networks. These switches connect end-user local area networks (LANs) to Internet service provider (ISP) networks. Edge switches can be routers, routing switches, integrated access devices (IADs), multiplexers and a variety of MAN and WAN devices that provide entry points into enterprise or service provider core networks. Edge switches can directly connect client devices, such as laptops, desktops, security cameras, and wireless access points, to your network.

what is edge switch

Core Switch vs. Edge Switch

Generally speaking, a core switch would have more up-market features such as higher backplane speed, layer 3 including routing protocols such as OSPF, and physical redundancy features such as removable PSUs. They might not have any copper presentation at all. A core switch will typically have deeper buffers, such that multiple connections can be experiencing congestion.

Edge switches are what your desktops and phones plug directly into (at the “edge of the network”). Typically they are lighter on features and more about copper port count and some form of fibre interface into the backbone / core.

How Should I Make A Choice?

A small company with fewer than 100 employees should function well with one core switch. However, as your business—and your network—grow, you might need to expand the number of core switches to two or more. In this case, you might want to consider stackable switches, which further simplify management.

Edge switches generally are considered less crucial than core switches to a network’s smooth operation. If there are areas of the office such as a conference room where you don’t need the features of a fully managed switch, your company can save some money by installing smart switches. But if you can’t tolerate any downtime whatsoever, want to maintain tight security throughout your office, or have the infrastructure to be able to add multiple different types of applications in the future, you should consider outfitting your entire network with managed switches.

Conclusion

Fortunately, managed switches are no longer out of reach for small businesses. Not long ago the price gap between managed and smart switches was as much as 40 percent. Today, though, that difference has shrunk to 10-20 percent. If you’re unsure which switch will meet your business’s needs, FS.COM, a manufacturer specializing in networking can help you choose the product that’s just right for you. Besides, we also offer other network related optic products like fibre optic transceivers, copper wires, fibre patch cable and so on. For more details, please visit www.fs.com/uk.

Huawei vs Cisco Switch: Which to Choose?

As we all know, Cisco System is one of the biggest multinational technology conglomerate in the world for decades. Its network devices, such as routers, switches..are popular in their customers. We can believe that Cisco will develop stronger, but new and strong competitors are arising, like Huawei. Huawei is one of the largest telecommunications equipment manufacturer in the world, having overtaken Ericsson in 2012. Both are the giants of network switch manufactures. Both switches offer more than enough bandwidth to be capable of forwarding at line rate for all ports. Both switches are designed to use the minimum amount of power possible at all times, earning them Green designations. Huawei vs Cisco: which one should I choose? Read on to know more about these Huawei vs Cisco switches.

huawei vs Cisco

Cisco vs Huawei Switches

Before we cut to the chase, let’s take a look at the comparison between Cisco vs Huawei switches. Although the function of the switch is the same, different brands have different features.

Switches Series

Now, Cisco switches have many series. The popular series, enterprise switches, are Catalyst series and Nexus switches. Cisco Catalyst series includes 2960 series, 3650 series, 3850 series, 4500E series, etc. Cisco Nexus series includes 9000, 7000, etc. Huawei switches also have various series. There are data centre switches, campus switches and SOHO & SMB switches. The popular one is the campus switches. In all the campus switches, the S5700 series is the hottest switches in enterprises.

Product Code Rules

Except the different series, there are also differences of their switches product code rules. Take Cisco WS-C3850-24T-L and Huawei S5700-28X-LI-AC switches as an example.

Cisco WS-C3850-24T-L Code Introduction:

  • WS=Switch, C=catalyst, 3850=3850 series
  • 24=Ethernet Port Number
  • T=Ethernet Ports
  • L=LAN Base image

Huawei S5700-28X-LI-AC Code Introduction:

  • S=switch
  • 57=5700 Series
  • 00=5700 Sub Series like 5710 series
  • 28=the biggest number of data interfaces is 48, including uplinks and downlinks
  • Li=Lite software Image
  • AC=Ac power supply
Huawei vs Cisco: Switch Comparison 

Here is a one-to-one mapping between cisco 2960x and huawei s5700 switches, covering the relationship of them and help you choose the best network switch for your need.

About Cisco Catalyst 2960-X Series Switches

Cisco Catalyst 2960-X Series are stackable Gigabit Ethernet Layer 2 and Layer 3 access switches that provide enterprise-class access for campus and branch applications. Designed for operational simplicity to lower total cost of ownership, they enable scalable, secure and energy-efficient business operations with intelligent services and a range of advanced Cisco IOS Software features.

Cisco Catalyst 2960-X Series Switches feature:

  • 4 or 48 Gigabit Ethernet ports with line-rate forwarding performance
  • Gigabit Small Form-Factor Pluggable (SFP) or 10G SFP+ uplinks
  • FlexStack-Extended capabilities for out-of-the wiring-closet distance stacking of up to 8 switches with 40 Gbps of stack throughput (optional)
  • FlexStack-Plus for stacking of up to 8 switches with 80 Gbps of stack throughput (optional)
  • Power over Ethernet Plus (PoE+) support with up to 740W of PoE budget
  • 4-port PoE fanless switch for deployment outside the wiring closet
  • Reduced power consumption and advanced energy management features
  • USB and Ethernet management interfaces for simplified operations
  • Application visibility and capacity planning with integrated Full (Flexible) NetFlow and NetFlow-Lite
  • AN Base or LAN Lite Cisco IOS software features
  • Enhanced Limited Lifetime Warranty (E-LLW) offering next-business-day hardware replacement
  • Identify, classify and control of trusted internal network traffic through Domain Name System as an Authoritative Source (DNS-AS)

Cisco Catalyst 2960-XR Series Switches also offer:

  • Power resiliency with optional dual field-replaceable power supplies
  • P Lite Cisco IOS software with dynamic routing and Layer 3 features
About Huawei S5700 Series Gigabit Enterprise Switches

The S5700 series gigabit enterprise switches are next-generation energy-saving switches developed by Huawei to meet the demand for high-bandwidth access and Ethernet multi-service aggregation. S5700 provides a large switching capacity and high-density GE ports to accommodate 10 Gbit/s upstream transmissions. The S5700 can be used in various enterprise network scenarios. For example, it can function as an access or aggregation switch on a campus network, a gigabit access switch in an Internet data centre (IDC), or a desktop switch to provide 1000 Mbit/s access for terminals.

  • Dual power slot
  • Intelligent stacking(iStack), supporting a maximum of 9 switches in a stack
  • Hardware BFD, hardware Ethernet OAM
  • Netstream
  • Energy-Efficient Ethernet(EEE)
Huawei vs Cisco: Comparison Chart of Cisco 2960-X and Huawei S5700

Comparison Chart of Cisco 2960-X and Huawei S5700

FS.COM White Box switches and Compatible Transceiver Modules

FS 40G/100G switches provide high performance, increased availability, low latency and better serviceability for next-generation data centres and enterprise networks in different applications. And they also support spine-leaf network topology that leverage commoditized hardware for the best price/performance, just as shown below.

100g-switches

Summary

Huawei vs Cisco, we can’t say which one is better than the other. Cisco switches meet the needs of organizations and offices of all sizes and sorts. As for Huawei, it has several product lines that are similar to Cisco devices, but have their own network hardware lines and IT solutions for different network demands. It all depends on what you need and of course your budget. Also as a global high performance data centre solutions provider, FS.COM provides various networking devices for your reference like optical transceiver, which is compliant with the major brand, patch lead for customised service and also Ethernet switches.

Related Article: Cisco Catalyst 3750 Series Switches SFP Port Connections

Managed vs. Unmanaged Switch: Which to Choose?

Before we talk about managed and unmanaged switch, we should first and foremost figure out what a switch is. Switches are boxes that connect a number of other devices together on a Local Area Network (LAN) and utilise what is called packet switching to effectively forward data to and from connections. Generally, There are two types of switch—managed and unmanaged switch. Here we will discuss the differences between managed switch vs unmanaged switch and why managed switch is recommended.

Manged Switch vs Unmanaged Switch: What Is the Difference?

An unmanaged switch on the other hand behaves like a “plug and play” device. It cannot be configured and simply allows the devices to communicate with one another. They tend to be less expensive than managed switches, as they have lower capacity and less flexibility. Generally, they don’t see much use outside of smaller and less intensive networking environments. Managed switches are fully configurable, and can be monitored and adjusted at your discretion. Although the management method and degree of configuration varies, they are typically more expensive than unmanaged switches, but offer much greater flexibility.

managed switch vs unmanaged switch

Manged Switch vs Unmanaged Switch: Why Choose Managed Switch?

There are several reasons why a managed switch is recommended.

48 Ports Managed Business Gigabit PoE+ Switch

Remote Access/Control

Managed switches give you better control over your LAN traffic and offer advanced features to control the traffic. Managed switches have all the features of an unmanaged switch and additionally have the ability to configure, manage, and monitor your LAN. So this helps you to monitor and decide who should have access to your network and gives you greater control over data flow through your network.

Security

With a managed switch you can secure your network connections and also protect any unused ports on your switch. For example, if there is an unused port on your managed switch, you can disable that port or even apply MAC address filtering so as not to allow unauthorised users or devices to access the network by just plugging in. Managed switches also require additional authentication through password protection of the network.

Redundancy

Redundancy means to provide an alternate data path to network traffic to safeguard a network in case a connection or cable fails. Managed switches incorporate Spanning Tree Protocol or STP to provide path redundancy in the network. This provides redundant paths but prevents loops that are created by multiple active paths between switches. STP allows one active path at a time between two network devices, prevents loops, and establishes redundant links as backups so that there is lesser downtime. This makes job for a network administrator easier and also proves more profitable for a business.

Quality of Service (QoS)

The Quality of Service (QoS) feature of a managed switch also allows you to prioritize your network traffic by assigning a higher priority to the critical traffic. This helps to improve network performance and helps in better transmission of delay-sensitive data such as real-time voice. So by assigning highest priority to voice data you can ensure the voice packets don’t get dropped or delayed and mangled during transmission and you can hear crystal clear voice during a conversation.

Port Mirroring

Port mirroring is a feature used on managed switches which helps to diagnose network problems. A Managed Switch allows you to configure Port Mirroring to send copies of traffic to a single port on the same switch for analysis by a network analyser. The network analyser then allows you to diagnose and fix problems without taking the network out of service, reducing downtime.

Conclusion

When it comes to managed switch vs unmanaged switch, a managed switch is more intelligent and offers more control, flexibility, and features, some you may not even know you need. So if you are still undecided between an unmanaged and a managed switch, then please do not hesitate in getting in touch with FS.COM. We will be more than happy to help with your networking needs.

Related Article:Managed 24 Port PoE Switch: How Can We Benefit From It?

Layer 3 Switch vs Router: Which to Choose?

Speaking of layer 3 switch and router, everyone may be confused about the two terms, because they both take IP packets, examine the destination address and pass the packet according to routing rules. It seems that the network switch is identical to a router in this way. Actually, they do have some difference not only in function, but also in other aspects. This article will explain how layer 3 switch vs router: how they differ from each other and a better option will be suggested for your reference.

Basics About Layer 3 Switch vs Router

In general, a layer 3 switch (routing switch) is primarily a gigabit switch (a Layer-2 device) that has been enhanced or taught some routing (Layer 3) capabilities and it was conceived as a technology to improve on the performance of routers used in large local area networks (LANs) like corporate intranets.

A router is a Layer-3 device that simply does routing only. In the case of a switching router, it is primarily a router that may use switching technology (high-speed ASICs) for speed and performance (as well as also supporting Layer-2 bridging functions).

Comparison Between Layer 3 Switch vs Router

layer 3 switch vs router

Performance versus cost—Layer 3 switches are much more cost effective than routers for delivering high-speed interVLAN routing. High performance routers are typically much more expensive than Layer 3 switches.

Port density—Layer 3 switches, have higher port count. Routers on the other hand typically have a much lower port density.

Flexibility—Layer 3 switches allow you to mix and match Layer 2 and Layer 3 switching, which means that you can configure a Layer 3 switch to operate as a normal Layer 2 switch, or enable Layer 3 switching as required.

WAN technologies support—Layer 3 Switch is limited to usage over LAN environment where Inter VLAN routing can be performed. However, when it comes to working on WAN and edge technologies, Layer 3 Switch lags behind. Router is the front runner in such scenario where WAN technologies such as Frame Relay or ATM need to be fostered.

Hardware/Software decision making—The key difference between Layer 3 switches and routers lies in the hardware technology used to build the unit. The hardware inside a Layer 3 switch merges that of traditional switches and routers, replacing some of a router’s software logic with hardware to offer better performance in some situations.

Layer 3 Switch vs Router: When and Where to Use

Now let’s look into the scenarios when should Layer 3 switch or router be used.

When Is A Layer 3 Switch needed?

1. If you need to connect your Hub rooms and make an L3 decision and more Ethernet interfaces are required for direct server form connectivity, then you can use a switch.

2. If you need to connect your inter-offices via l2 circuits by the ISP you can directly terminate the link on the switch and configure routing on the same.

3. If you need more through-put and direct access and interVLAN communication, switch is the best option.

When Is A Router Needed?

1. If you are connecting an ISP directly to provide internet, then router is the box you need to deploy.

2. If you need to build tunnels between your offices (connecting 2 offices over the public internet securely ), then you need a router.

3. If you are a CE participating in MPLS configuration, then you need a router.

Conclusion

Having explained the mechanism of Layer 3 switch vs router, I guess you’ve already have an understanding of them. Simply put, they perform the same function but each has pro’s and con’s as to limitations. Generally, Layer 3 switches are primarily used in the LAN environment, where you need routing. Routers are used in the WAN environment. These days lots of people have started using layer 3 switches in WAN environment, like MPLS. If you are looking for switches or any fibre optic cables and optical transceivers for switches, take FS.COM as a consideration. Or if you have any question about your network deployment, feel free to contact tech@fs.com for help.

Related Article: Layer 2 vs Layer 3 Switch: Which One Do You Need?

Cisco Catalyst 9000 Series Switches: What’s New?

Recently, Cisco unveiled the Catalyst 9000 family, shaping the new era of intent-based networking. The Network. Intuitive. The Cisco Catalyst 9000 series switches are the next generation of enterprise-class switches built for security, Internet of Things (IoT), mobility, and cloud. These switches form the foundational building block for Cisco Software Defined Access (SD-Access). And what’s more, they also support full IEEE 802.3at Power over Ethernet Plus (PoE+), and Universal Power over Ethernet (UPoE). These switches enhance productivity by enabling applications such as IP telephony, wireless, IoT, and video for a true borderless network experience. This post will take a closer look at Catalyst 9000 switches and some highlights of them.

Members of the Cisco Catalyst 9000 Family

The Cisco Catalyst 9000 series switches come in three main varieties.

Members of the Cisco Catalyst 9000 Family

  • The Catalyst 9300 is top fixed-access enterprise network switch series, stacking to 480Gbps. The Cisco Catalyst 9300 switches feature a fixed number of switch ports (1G 48-port, 1G 24-port, or 24 ports of 1G/2.5G/5G/10G).
  • The Cisco Catalyst 9400 is the leading modular-access switches for enterprise, which can support up to 9Tbps. It features 7-slot and 10-slot variety.
  • The Catalyst 9500 is the industry’s first fixed-core 40Gbps switch for the enterprise. It comes in three different varieties, a 24 port 40G switch, a 12 port 40G switch, and a 40 port 10G switch with 10/40G uplinks. The Cisco Catalyst 9500 is meant for distribution and core use.
New Design

The Catalyst 9000 series have some special design choices, which make Catalyst 9000 the industry’s most aesthetic switches.

  • Rounded frame without sharp corners, changing the traditional switch outline.
  • Ergonomic pullout handles on the Catalyst 9400 enable better weight distribution. You don’t have to carry it on your back or worry about breaking your back when lifting these switches!
  • Innovative slide-out ejectors with latch on the uplink modules of Catalyst 9500. Screwdrivers can be abandoned!
  • Molded plastic covers ejectors, screws and handles on field replaceable units. Gloves are needless!
  • Industry standard icons now advertise the capabilities of the switch–a truly universal switch!
  • The Catalyst 9400 chassis introduces user-configurable dual serviceable fan-tray design, allowing users to service the same fan-tray from the front and rear of the chassis.
  • The Catalyst 9300 Series switches support a blue beacon LED for easy identification of the switch being accessed.

new design choices

New Software

The new Cisco Catalyst 9000 switches use an Intel x86 processor to help create a network that constantly learns and adapts. Above the feature, Cisco adopts a central software console called the Cisco Digital Network Architecture (DNA) Centre that replaced the obsolescent and deprecated command-line interface (CLI). DNA is about bringing the power of automation, ease of management, and predictable performance to networks while driving down cost.

New Packaging

The Catalyst 9300 Series introduces new licensing packaging: Network Essentials and Network Advantage, which feature vastly simplified base network packages. Additionally, there are two licensing levels for Cisco DNA, namely Cisco DNA Essentials and Cisco DNA Advantage, which are hardware and term-based software packages used as mandatory add-ons. In addition to on-box capabilities, the Cisco DNA packages unlock additional functionality in Cisco DNA Centre (in APIC-EM), enabling controller-based software-defined automation in your network. License consumption is further simplified with the package combinations of Essentials and Advantage.

Transceiver Options for Cisco Catalyst 9000 Series Switches

The following diagram lists the supporting detailed transceiver options for Catalyst 9300 Series. Take C9300-NM-4G as an example, this module has four 1G SFP module slots. Any combination of standard SFP modules are supported.

Model ID Description
11773 Cisco GLC-T Compatible 1000BASE-T SFP Copper RJ-45 100m Transceiver
34976 Cisco GLC-TA Compatible 10/100/1000BASE-T SFP Copper RJ-45 100m Transceiver
12622 Cisco SFP-GE-L Compatible 1000BASE-LX/LH SFP 1310nm 10km DOM Transceiver
48928 Cisco SFP-GE-S-2 Compatible 1000BASE-SX SFP 1310nm 2km DOM Transceiver
39297 Cisco GLC-TE Compatible 1000BASE-T SFP Copper RJ-45 100m Transceiver
15413 Cisco Linksys MGBT1 Compatible 1000BASE-T SFP Copper RJ-45 100m Transceiver
12624 Cisco SFP-GE-Z Compatible 1000BASE-ZX SFP 1550nm 80km DOM Transceiver
39370 Cisco Meraki MA-SFP-1GB-SX Compatible 1000BASE-SX SFP 850nm 550m DOM Transceiver
28299 Cisco ONS-SE-ZE-EL Compatible 10/100/1000BASE-T SFP Copper RJ-45 100m Transceiver


Summary

The Cisco Catalyst 9000 series switches solves some persistent challenges of enterprise networks by utilising platform innovations built around four key areas: security, Internet of Things (IoT) convergence, mobility and cloud readiness. There is no doubt that Catalyst 9000 is leading us to a new era of faster and securer network. And if you need any transceiver or cables for mating Cisco Catalyst 9000 series, please contact us via sales@fs.com. All the products offered by FS.COM are tested before shipping to ensure superior quality.

ABCs of Optical Switch

Optical networking technology has solved the problem of increasing demand for higher transfer data rates and larger bandwidths. In optical network, optical fibre is the fundamental medium of transmission. However, switching, signaling and processing functions are accomplished electronically. So optical switches are naturally developed. Optical switches are widely used for optical protection, test systems (as shown in the following figure), and remotely reconfigurable add-drop multiplexers, etc.

fs.com-switch

Figure 1. Switch for FS.COM transceiver compatibility test

Two Types of Optical Switches

An optical switch is simply a switch which accepts a photonic signal at one of its ports and send it out through another port based on the routing decision made. There are two kinds of optical switches, including O-E-O (optical–electrical–optical) and the O-O-O (optical–optical–optical) also called all optical switch. OEO switch requires the analogue light signal first converted to a digital form to be processed and routed before being converted back to an analogue light signal. While OOO switching is done purely through photonic means.

oeo and ooo

Advantages of Optical Switches

Compared with electrical switches, optical switches have many advantages.

On one hand, optical switches can save floor space and power consumption significantly. They can save up to 92 percent space and 96 percent power. If translating power savings into cost, it means 3 kw can be reduced for each rack. This can save the carrier from expensive diesel power generators, rectifiers and batteries, the monthly maintenance costs for these devices and the purchasing and maintenance of cooling equipment for these devices.

On the other hand, optical switches are a lot more scalable and faster than electric switches, as all-optical switches are protocol and bit rate independent. Because of the scalability and flexibility all-optical switches have, so transfer rates will not be affected bit rate limitations of switching equipment.

Problems of Optical Switches

Despite those advantages, optical switches still have some problems.

Current optical switching technology can’t realize the technology that photonic signals can be as stored as easily as electrical signals. It is possible to store them using fibre delay lines, as light take a certain time to travel through lengths fibre (200,000 km per second in silica). That means a 10000 bit frame traveling at 10G b/s requires 200m of fibre. This is both expensive and impractical. And once a signal is put through a delay line, it cannot be processed until it comes back out. A solution to this is through adding switches within the lines, but that needs more costs.

The other problem with all – optical switching is that it cannot process header information of packets, especially at such high speed which the signals travel at. The maximum speed electronic routers currently can operate is at 10 Gb/s while optical signals can travel up to 40/100G or even higher. Thus, the routers will not be able to process the signals as fast as the transmission.

Applications of Optical Switches

Optical switches are widely applied in the network.

First, optical switches are used in high speed network which requires very high switching speeds and also requires very large switches to handle the amount of traffic. So switches are likely used within optical cross-connects (OXC). OXC are similar to electronic routers which forward data using switches. An OXC may contain a whole series of optical switches.

Second, optical switches are used for switching protection. If a fibre fails, the switch allows the signal to be rerouted to another fibre before the problem occurs. But this will take milliseconds including detecting the failure, informing the network and switching. Normally this operation requires a 1×2 switch but with complicated cross-connects hundreds may be required.

Third, optical switches can be also used for external modulators, OADM (optical add-drop multiplexers), network monitors and fibre optic component testing.

Conclusion

As the demand for video and audio increasing the challenge of data capabilities and high bandwidth of networks, optical network is absolutely the most cost-effective solution. Optical switches can provide the customers with significant power, space and cost savings. Today, the optical switch market is dominated by several companies, such as Cisco, HP, Arista, Juniper. In early days, original optical transceivers were required to be plugged into these switches. Later, to save the cost, third-party optical transceivers were produced. If you need optical transceivers compliant with these switches, please visit FS.COM.

Advanced Optical Components – Optical Switch

Optical switch (or fibre optic switch) can be a mechanical, opto-mechanical, or electronic device that opens or closes an optical circuit. The optical switch can be used to complete or break an optical path. Passive fibre optic switches will route an optical signal without electro-optical or opto-electrical conversion. However, a passive optical switch may use an electromechanical device to physically position the switch. An optical switch may have one or more input ports and two or more output ports. Here is an opto-mechanical optical switch with one input port and four output ports, that is, a 1 × 4 Optical Switch).

Fiberstore's 1 × 4 Opto-Mechanical Optical Switch

As with any other type of switch, the optical switch has many uses, depending on the complexity of the design. In essence, the switch is the control for making, breaking, or changing the connections within an optical circuit. This definition can be expanded to incorporate the concept of the switch as the control that interconnects or transfers connections from one optical circuit to another.

According to the operating principle and function, there are three types of optical switches: Opto-Mechanical Switch, Thermo-Optic Switch, Electro-Optic Switch. Note: FS has been expanding the product line of optical switches, but not include the thermo-optic and electro-optic switches yet.

Opto-Mechanical Switch

An opto-mechanical switch redirects an optical signal by moving fibre or bulk optic elements by means of mechanical devices. These types of optical switches are typically stepper motor driven. The stepper will move a mirror that directs the light from the input to the desired output, as shown in the figure below. Although opto-mechanical switches are inherently slow due to the actual physical movement of the optical elements, their reliability, low insertion losses, and minimal crosstalk make them a widely deployed type of optical switch.

Structure of Opto-Mechanical Optical Switch

The opto-mechanical switch works on the premise that the input and output light beams are collimated within the fibre and “matched” within the switching device (the beams are moved within the device to ensure the switched connection from the inputs to the outputs). The opto-mechanical switch can be physically larger than alternative switches, but there are many micromechanical fibre optic switches becoming available, such as the Micro Electro Mechanical Systems (MEMS) optical switch. Here is a Mini 1 × 4 Opto-Mechanical Switch and an 1 × 8 MEMS Optical Switch from FS.

Mini 1 × 4 Opto-Mechanical Switch 1 × 8 MEMS Optical Switch

Thermo-Optic Switch

The thermo-optic switch is based on waveguide theory and utilises waveguides made in polymers or silica. In other words, this optical switch utilises the thermal/refractive index properties of the device’s material. The principle of this switch relies on the altering of the waveguide’s refractive index due to a temperature change.

The temperature change can be accomplished in many ways, but generally the device is heated by using a resistive heater, which has the effect of slowing down light in one of the paths. The device then combines the light in the two paths in a constructive or destructive effect, making it possible to attenuate or switch the signal. This type of switch is inherently slow due to the time it takes to heat the waveguide. It’s like a burner on an electric stove: it takes a while to heat up and a while to cool down.

This type of device typically has less optical loss than the opto-mechanical switch. Thermo-optic switches are attractive for several reasons: they work well in low optical power applications, are small in size, and have the potential to be integrated with a number of devices based on silicon wafer theory.

Electro-Optic Switch

Electro-optic refers to a variety of phenomena that occur when an electromagnetic wave in the optical spectrum travels through a material under the stress of an electric field. An electro-optic switch is based on the changing of the refractive index of a waveguide by using an electric field. This device is semiconductor-based and therefore boasts high speed and low optical power loss similar to that of the thermo-optic devices. This device is still in the research stage; however, the technology is rapidly advancing.

Optical switches can be used in a variety of applications, large and small. The use of a fibre optic switch allows data to be routed where and when it is needed. It is important to be aware of the basic parametre for an optical switch when choosing a right one. Some of the performance parametres to consider are Required Size (the number of input and output ports), Optical Fibre Type, Connector Type, Centre Wavelength, Bandwidth, Losses, Crosstalk, Switching Speed, Durability (number of switching cycles), Power Handling, and Repeatability (the amount of change in output power each time the switch changes state). Note: Most of the parametres above are mentioned in the previous post: The Basic Parametres of Passive Optical Network Devices.