The numbers 1310 and 850 refer to the wavelengths of light used in SFP (Small Form-Factor Pluggable) transceivers for optical communication. Here are the key differences between 1310nm and 850nm SFP modules: 

1. Wavelength:

• The "850" indicates that the SFP module operates at a wavelength of approximately 850 nanometers.

• This wavelength falls in the near-infrared range.

• The "1310" indicates that the SFP module operates at a wavelength of approximately 1310 nanometers.

• This wavelength falls in the infrared range of the electromagnetic spectrum.

• 1310nm SFP:

• 850nm SFP:

2. Fiber Type:

• Typically used with multimode fiber (MMF).

• Multimode fiber is suitable for shorter-distance transmissions within data centers or local area networks.

• Typically used with single-mode fiber (SMF).

• Single-mode fiber is designed for longer-distance transmissions.

• 1310nm SFP:

• 850nm SFP:

3. Distance:

• Suitable for shorter-distance connections, typically within the range of a few hundred meters to a couple of kilometers.

• Generally used for longer-distance connections, with transmission distances potentially reaching tens of kilometers.

• 1310nm SFP:

• 850nm SFP:

4. Applications:

• Commonly used in data center environments or short-distance connections within buildings.

• Commonly used in applications requiring longer-distance communication, such as metropolitan area networks (MANs) or long-haul connections.

• 1310nm SFP:

• 850nm SFP:

5. Attenuation:

• Multimode fiber at 850nm has higher attenuation compared to single-mode fiber, limiting the maximum transmission distance.

• Single-mode fiber at 1310nm generally has lower attenuation, allowing for longer-distance transmission.

• 1310nm SFP:

• 850nm SFP:

6. Optical Characteristics:

• Typically uses light-emitting diodes (LEDs) as light sources.

• Typically used with lasers as light sources.

• 1310nm SFP:

• 850nm SFP:

When selecting an SFP module, the choice between 1310nm and 850nm depends on the specific requirements of the networking infrastructure, including the desired transmission distance and the type of fiber optic cabling used in the deployment. Always refer to the documentation provided by the SFP module manufacturer and consider the compatibility with the existing optical infrastructure.