Elliptical polarization

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 (r_e) 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. It may be given by

$r_{e}={\frac {P_{1}}{P_{0}}}$,

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 is the ratio of optical powers of perpendicular polarization, usually called TE (transverse electrical) and TM (transverse magnetic).

References

• Template:FS1037C
• Material also incorporated from MIL-STD-2196.