Extinction ratio

From Wikipedia, the free encyclopedia
  (Redirected from Polarization extinction ratio)
Jump to navigation Jump to search
Eye diagram showing an example of two power levels in an OOK modulation scheme, which can be used to calculate extinction ratio. P1 and P0 are represented by (binary 1) and (binary 0) respectively.

In telecommunications, extinction ratio (re) is the ratio of two optical power levels of a digital signal generated by an optical source, e.g., a laser diode. The extinction ratio may be expressed as a fraction, in dB, or as a percentage.[1] It may be given by

where P1 is the optical power level generated when the light source is on, and P0 is the power level generated when the light source is off.

The polarization extinction ratio (PER) is the ratio of optical powers of perpendicular polarizations, usually called TE (transverse electrical) and TM (transverse magnetic). In telecommunications, the PER is used to characterize the degree of polarization in a polarization-maintaining device or fiber. For coherent transmitter and receiver, the PER is a key parameter, since X polarization and Y polarization are coded with different signals.

References

  1. ^ "Extinction Ratio". Timbercon. Retrieved May 14, 2009.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Extinction_ratio&oldid=821186022"
This content was retrieved from Wikipedia : http://en.wikipedia.org/wiki/Polarization_extinction_ratio
This page is based on the copyrighted Wikipedia article "Extinction ratio"; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA