What is SR/LRM/LR/ER/ZR in Optical Transceiver Modules?

SR/LRM/LR/ER/ZR are different types of optical transceiver modules used in networking equipment to transmit and receive data over fiber optic cables.

- SR (Short Reach): SR transceivers are designed for short distance transmission, typically up to 300 meters. They are commonly used in data centers and other short-range applications.

- LRM (Long Reach Multimode): LRM transceivers are designed for longer distance transmission over multimode fiber, typically up to 220 meters. They are used in applications where longer reach is required but single-mode fiber is not available.

- LR (Long Reach): LR transceivers are designed for longer distance transmission over single-mode fiber, typically up to 10 kilometers. They are commonly used in enterprise networks and telecommunications applications.

- ER (Extended Reach): ER transceivers are designed for even longer distance transmission over single-mode fiber, typically up to 40 kilometers. They are used in applications where longer reach is required, such as metropolitan area networks.

- ZR (Zero Reach): ZR transceivers are designed for ultra-long distance transmission over single-mode fiber, typically up to 80 kilometers. They are used in long-haul and high-capacity network applications.

SR (Short-Reach)

- Designed for short distances up to 100 meters
- Typically used for intra-rack connections or within data centers
- Uses multi-mode fiber (MMF)

LRM (Long-Reach Multimode)

- Extended version of SR
- Supports distances up to 550 meters
- Also uses MMF for intra-rack or data center connections

LR (Long-Reach)

- Designed for distances up to 10 kilometers
- Uses single-mode fiber (SMF)
- Common transceiver types include LR4 and LR10

ER (Extended Reach)

- Extended version of LR
- Supports distances up to 40 kilometers
- Also uses SMF
- Examples include ER4 and ER10 transceivers

ZR (Zero Dispersion Reach)

- High-performance transceiver with advanced modulation techniques
- Designed for distances up to 120 kilometers
- Uses SMF with dispersion compensation
- Common types include ZR4, ZR10, and ZR40

When you're looking for an SFP optical transceiver, you'll see some abbreviations such as SR, LRM, LR, ER and ZR in transceiver module name. They might be confusing for you. These abbreviations actually tell the characteristics of the modules. SR, LRM, LR, ER and ZR are terms that are commonly seen on 10G SFP+ modules, and they stand for the transmission distance of the modules. Let us have a look into their meanings in this article. 10GBase-SR SR stands for "Short Range". These transceivers support links up to 300 meters on multimode fiber and operate in 850nm wavelength. 10GBase-SR is the original multimode optics specification and is still the most commonly used ones by far. Adopting single low-cost solid-state laser assembly, it is also the cheapest 10GbE optical module available. 10GBase-LRM LRM stands for "Long Range Multimode". These transceivers support links up to 220 meters on multimode fiber and operate in 1310nm wavelength. It is the replacement of 10GBase-LX4. 10GBase-LR LR stands for "Long Range". These transceivers support links up to 10km on single mode fiber and operate in 1310nm wavelength. There is no minimum distance for LR, so it is also applicable for short connections on single mode fiber. 10GBase-ER ER stands for "Extended Range". These transceivers can support links up to 40 km on single mode fiber and operate in 1550nm wavelength. Its transmission can reach 40km over engineer links, and 30km over standard links. Due to laser power, attenuation is required for links less than 20km. 10GBase-ZR ZR also stands for "Extended Range". It can support links up to 80km on single mode fiber and operate in 1550nm wavelength. Due to its very high laser power, significant attenuation is required for shorter links. To ensure a trouble-free deployment, the use of ZR should be preceded by optical power test of the fiber span in question. Most suppliers provide options for ZR, although it is actually not an official format and is technically not part of the IEEE 802.3ae standards for networking hardware. https://www.glsun.com/article-p77-what-is-sr-lrm-lr-er-zr-in-optical-transceiver-modules.html