Unit 8 Assignment 1

Topics: Optical fiber, Refractive index, Motivation Pages: 5 (975 words) Published: April 19, 2015
A splice is a permanent connection of two optical fibers. Once the two optical fibers are joined with a splice, they cannot be taken apart and put back together as they can if you join them using connectors. A splice is typically employed for one of three reasons: to repair a damaged cable, to extend the length of a cable, or to join two different cable types. (Andrew Olivier, 2011, p. 617) There are some things that can affect splicing performance. There is Cladding Diameter which occurs when the cladding diameters of the transmit and receive optical fibers are not the same. Cladding diameter mismatch loss occurs when the cores of the optical fiber are not aligned because of the cladding diameter mismatch. Cladding diameter mismatch can cause the light exiting the core of the transmitting optical fiber to enter the cladding of the receiving optical fiber. The light entering the cladding is lost, causing attenuation. (Andrew Olivier, 2011, p. 620) Clad Concentricity variations can cause the optical fiber cores to misalign causing a loss when the light exiting the core of the transmitting optical fiber enters the core of the receiving optical fiber. The illustration in Figure 25.5 is greatly exaggerated to clearly show how a concentricity loss may occur. The core and cladding concentricity differences are typically less than 1μm. The noncircularity of the core will cause a loss when light from the core of the transmitting optical fiber enters the cladding of the receiving optical fiber. Cladding noncircularity may cause loss when it causes part of the core of the transmitting optical fiber to align with the cladding of the receiving optical fiber. Any light that enters the cladding of the receiving optical fiber will be lost, causing attenuation. (Andrew Olivier, 2011, pp. 620-621)

The variations between two optical fibers that affect splice performance are referred to as intrinsic factors. One of the instrinsic factors that can affect connection performance is a Numerical Aperture (NA) mismatch occurs when the NA of one optical fiber is different from the NA of the other optical fiber. If the NA of the transmitting fiber is larger than the NA of the receiving optical fiber, a loss may occur. However, a loss will not occur if the NA of the transmitting optical fiber is less than the NA receiving optical fiber. NA mismatch loss is typically only a concern with multimode optical fiber. (Andrew Olivier, 2011, p. 618) Core diameter mismatch occurs when there is a difference in the core diameters of the two optical fibers. A core diameter mismatch loss results when the core diameter of the transmitting optical fiber is greater than the core diameter of the receiving optical fiber. A loss occurs when light at the outer edge of the transmitting optical fiber core falls outside the diameter of the receiving optical fiber core. This light is lost in the cladding of the receiving optical fiber. Core diameter mismatch loss is typically only a concern with multimode optical fiber. (Andrew Olivier, 2011, p. 618) A mode field diameter mismatch occurs when there is a difference in the mode field diameters of two single-mode optical fibers. A mode field diameter mismatch loss results when the mode field diameter of the transmitting optical fiber is greater than the mode field diameter of the receiving optical fiber. A loss occurs when optical fiber with the smaller mode field diameter will not accept all of the light from the optical fiber with the larger mode field diameter. (Andrew Olivier, 2011, p. 620)

Another variation between two optical fibers that affect splice performance is extrinsic factor. Extrinsic factors that affect optical fiber splice performance are factors related to the condition of the splice itself, external to the optical fiber. In an ideal splice, the optical fibers are identical and they are aligned so that cores are perfectly centered on each other and the core axes are perpendicular to the endfaces being joined, as shown in Figure 25.7. However,...

Cited: Andrew Olivier, B. W. (2011). Cabling The Complete Guide to Copper and Fiber-Optic Networking 4th Edition. Danvers: John Wiley & Sons, Inc. .
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • Unit 8 Assignment 1 Essay
  • Nt1310 Unit 8 Assignment Essay
  • assignment brief unit 1 Essay
  • Unit 8 Assignment 1 Research Paper
  • Unit 8 Assignment 1 Essay
  • Assignment 1
  • Essay on unit 1 assignment 1
  • Assignment 1 Becoming an effective Leader Essay

Become a StudyMode Member

Sign Up - It's Free