Polarization Extinction Ratio Calculator Equation

Polarization Extinction Ratio Formula:

\[ PER = 10 \times \log_{10}\left(\frac{P_{max}}{P_{min}}\right) \]

Polarization Extinction Ratio (PER):

Definition: PER measures the quality of polarization in an optical system, comparing the maximum and minimum power states.

Purpose: It quantifies how well a system maintains polarization purity, important in fiber optics and laser applications.

The calculator uses the formula:

\[ PER = 10 \times \log_{10}\left(\frac{P_{max}}{P_{min}}\right) \]

Where:

Explanation: The ratio of maximum to minimum power is converted to decibels using a logarithmic scale.

Details: High PER values indicate better polarization purity, crucial for optical communication systems and polarization-sensitive instruments.

Tips: Enter both power values in watts. P_max must be greater than P_min for valid results.

Q1: What is a good PER value?
A: Typically >20 dB is good, >30 dB is excellent for most applications.

Q2: Can I use mW instead of W?
A: Yes, as long as both values use the same units (ratio will be identical).

Q3: Why is PER important in fiber optics?
A: It affects signal quality in polarization-sensitive systems like coherent communications.

Q4: What causes low PER?
A: Imperfections in polarizing elements, stress-induced birefringence, or misalignment.

Q5: How is PER measured experimentally?
A: By rotating a polarizer and measuring maximum/minimum transmitted power.