Single Mode Vs Multimode Fiber.

By | April 14, 2022

in a Single mode fiber, the core diameter is very thin and only one direction of light is allowed to pass through, that is, a single-mode fiber; the core diameter is generally 8.5 or 9.5 μm, and it works at 1310 and 1550 nm wavelengths.

in multimode the core diameter is thick, The core diameter of multimode fiber is generally 50μm/62.5μm. Due to the core runoff of multimode fiber, different modes of light can be tolerated. The wavelength used in multimode is between 850nm and 953nm.

Multimode fiber is designed to operate at 850 and 1300 nm, while single-mode fiber is optimized for 1310 and 1550 nm. … WDM can use the full range of wavelengths between 1260 and 1670 nm in various bands.

DIA of Fiber Core..

Single Mode Fiber.

  • SIngle-mode fiber cable excels at long-distance communication.
  • Single-mode cable is designed to carry a single light ray at a time due to the small core diameter.
  • Single-mode fiber has less attenuation and it can travel more distance.
  • Single-mode means the fiber enables one type of light mode to be propagated at a time.
  • This is used in Telecommunication networks.
  • In All categories of Single-mode cable, the cladding is 125 µm.

Single Mode Fiber.

Types of single-mode Fiber.

Single-mode fiber cable is categorized into OS1 and OS2 fiber cables. These two kinds of fiber cables have different characteristics for diverse applications. OS2 SMF cables can not be connected with OS1 SMF cables, which may lead to poor signal performance. Therefore, it’s of great significance to figure out the difference between OS1 and OS2 when conducting deployments. 

The maximum attenuation of OS1 is 1.0db/km for 1310nm and 1550nm, while the numerical value of OS2 is 0.4db/km for 1310nm and 1550nm. Consequently, the maximum transmission distance of OS1 single-mode fiber is 10 km, while the maximum transmission distance of OS2 single-mode fiber can reach up to 200 km. Both OS1 and OS2 single-mode fibers will allow speeds of 1 to 10GbE with varied transmission distances. Furthermore, the OS2 type of single-mode fiber optic cable can be applied for 40G/100G Ethernet connections.

Multimode Fiber

  • multi-mode has a larger core diameter
  • The larger core allows multiple light rays or modes (modalities) to be transmitted concurrently,.
  • This application is typically used for a short distance, data, and audio/video applications in LANs
  • Multimode fiber is currently constructed in five different grades: OM1, OM2, OM3, OM4, and OM5.
  • Each grade of multimode fiber has a different bandwidth and distance limitation,.
  • OM4 and OM5 provide the greatest bandwidth over the longest distance and OM1 provides the lowest.  It is extremely important to note that OM2, OM3, OM4, and OM5 all have a core of 50 µm.
  • OM1 has a core of 62.5 µm. 
  • In All categories of multimode cable, the cladding is 125 µm.
Multimode Fiber.

Types of Multimode Fiber.

Types of multimode Fiber.

Attenuation in Single Mode & Multimode Fiber.

  • The attenuation of multimode fiber is higher than SM fiber because of its larger core diameter.
  • The fiber core of single-mode cable is very narrow, so the light that passes through these fiber optic cables is not reflected too many times, which keeps the attenuation to a minimum