Polarizer Extinction Ratio
Analyze extinction ratio, Malus's law with imperfect polarizers, and cascaded extinction performance.
ER = T_max / T_min [linear]
T(θ) = T∥·cos²θ + T⊥·sin²θ
ER_cascaded = ER^n
T_parallel
95.0%
T_perpendicular
9.50e-2
Contrast at 0°
0.0 dB
Cascaded ER
60.0 dB
T = 90.3%
Transmission vs Angle
Cascaded Extinction Ratio
Model and references
Exact. The equations are exact within the stated assumptions, or are a standard's tabulated values. The results are as good as the inputs. About the tiers
Ideal diattenuators: linearly polarized light at θ to the pass axis gives T∥cos²θ + T⊥sin²θ; aligned polarizers in series multiply both. Not modelled: depolarization, misalignment, reflections.
- Goldstein D. H. (2011). Polarized Light, 3rd ed., ch. Mueller Matrices for Polarizing Components, pp. 93–115. CRC Press. doi:10.1201/b10436
- Shurcliff W. A. (1962). Polarized Light: Production and Use, ch. 3 Polarizers: classes and performance parameters, pp. 32–42 (principal transmittances k₁, k₂). Harvard University Press. doi:10.4159/harvard.9780674424135.c4