All You Need to Know About Single Mode Switches

Telecom and data networks, over the last few years, have become expansive and capable of long distance transmissions. Switches are an integral part of all modern networks, and in fact an important hardware device when it comes to upgrading legacy networks. They are either single mode or multimode. Single mode switches are versatile devices on the physical layer of the network. They support several functions such as switching, control, and access. These switches are widely used in fiber optic networks, especially in the telecom sector. They help make the network versatile and flexible, and perform signal routing, and either transmit or redirect optical signals to reach the right destination, in a fiber optic network. They may also block certain signals if required. Optical switches, whether single mode or multimode have a wide range of visible spectrum, and are highly reliable in terms of eliminating crosstalk and noise. This article focuses on single mode switches, their functioning, benefits, and more.

Single Mode Switches in Fiber Optic Network

Features of Single Mode Switches

As the term implies, single mode switches enable only one-way transmission from a source to destination. They have fibers with extremely thin diameter cores, which enables huge bandwidths and long geographical distances for data transmission. These switches comprise a number of ports, some of which are for regular RJ45 connectors in Ethernet networks, while others are SFP or SFP+ ports used for fiber optic cable connectivity. The number of ports may vary from 2 to 20 or more, depending on the type and model. They are capable of supporting dual wavelength. These switches can be customized to suit your application requirement.

Functioning of Single Mode Switches

While these switches transmit or reroute data packets, the actual functioning happens through some mechanical movements within the device. These devices comprise stepping motors and fiber optic collimators. The motor rotates, while the collimators are fixed. The function is performed based on the motor rotation.

Factors to Consider When Sourcing Single Mode Switches

While most switches can function as single and multimode, when using single mode for your applications, here are certain pointers which may be helpful.

  • Number of input and output ports: Based on your application requirements and the number of devices on the network, you can decide the number and types of ports. Consider more number of ports if you plan to expand the network and the connected devices. This makes the network scalable.
  • Types of ports such as for RJ45 connectors and SFP modules: In case you want to upgrade your existing legacy network, you can blend fiber optics which will vastly improve the network performance. Switches for such blended networks must have some SFP as well as Ethernet ports to connect SFP module and RJ45 connector respectively.
  • Wavelength or bandwidth offered: For medium to large networks, a good bandwidth is crucial for data transmission rate and distance. This ensures there is no weakening of signals and there is seamless connectivity. Weak signals are not an issue in fiber optic network. However, in blended networks, signal loss must be minimized.
  • Eliminating cross talk: While EMI and cross talk are eliminated in fiber optics as the data is in the form of light pulses, in case of blended networks, you can mitigate the issue with the right single mode fiber switch.
  • Data rate: Data rate is exceptionally high in fiber optics. However, in Ethernet networks, it needs to be extended, and this can be done through these network devices such as network switches and fiber media converters.
  • Insertion loss: Insertion loss is basically the signal loss when it traverses in or out from a component or a circuit, and is measured is decibels. This happens in case of weak signals or power loss. Single mode switches have low insertion loss rate, and are relatively more reliable than multimode switches.
  • Switching voltage: This is the maximum switching voltage of a relay, whether open or closed. This is applied to switches as well. Single mode switches offer fast switching speeds.
  • Operating temperatures: While most fiber optic switches are designed to work in harsh temperature ranges and industrial environments, it is essential to check the operational temperature range of the switch before buying.

Benefits of Single Mode Switches

There are many benefits of using single mode switches in a fiber optic network. Here are some of them:

  • Most of these switches have LED indicators which indicate various outputs or alerts. They have auto self-checking and alarm functions in case of a network breakdown.
  • The transmission distance and bandwidth are much larger in single mode compared to multimode switches.
  • They have low insertion losses and a high switching speed.
  • These versatile and reliable switches are compact and have a modular design.
  • Most of them have a simple plug and play operation method.
  • They are rack mountable or can be mounted on a rail.
  • They are designed to work in harsh industrial environments and even outdoors, and have a wide operating temperature range.

Applications of Single Mode Switches

Here are some of the application areas of single mode switches.

  • Optical switching and routing
  • Network monitoring
  • Backup and network security
  • Fiber optic component testing


Overall, switches are an integral part of a network which help in devising the best route to send the data packet, and help in date framing and transmission. Single mode switches have their own advantages in terms of reliability and signal strength among other factors. They are compatible with fiber as well as copper network devices, and have ports for both. The type of switch largely depends on your application requirements and expansion plans related to the network. Always prefer switches with more number of ports than your actual requirement. This leaves room for future expansion and makes the network scalable. Also, it is essential to source these switches from a reliable manufacturer and supplier. VERSITRON is one of the leading manufacturers of fiber optic network switches and various other devices such as connectors and media converters as well as installation kits. These devices are compatible with copper as well as fiber networks.