Polarization Extinction Ratio Calculator with Temperature

Polarization Extinction Ratio Formula:

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

Polarization Extinction Ratio (PER):

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1. What is Polarization Extinction Ratio (PER)?

Definition: PER measures the ratio of maximum to minimum optical power in polarization-maintaining fibers, expressed in decibels (dB).

Purpose: It quantifies how well a fiber maintains polarization states, crucial for optical communication systems.

2. How Does the Calculator Work?

The calculator uses the formula:

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

Where:

\( PER \) — Polarization Extinction Ratio (dB)
\( P_{max} \) — Maximum power in the preferred polarization (W)
\( P_{min} \) — Minimum power in the orthogonal polarization (W)

Explanation: The ratio of maximum to minimum power is converted to logarithmic scale (dB) for practical measurement.

3. Importance of Temperature Consideration

Details: Temperature affects PER measurements as it can induce stress and birefringence changes in optical fibers. The calculator includes temperature input for more accurate results.

4. Using the Calculator

Tips: Enter the maximum and minimum power values in watts, and the temperature in °C. Ensure P_max > P_min > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a good PER value?
A: Typically > 20 dB is good, > 30 dB is excellent for polarization-maintaining fibers.

Q2: How does temperature affect PER?
A: Higher temperatures generally decrease PER due to increased random polarization fluctuations.

Q3: What instruments measure PER?
A: Polarization analyzers or optical power meters with polarizers are commonly used.

Q4: Why use logarithmic scale (dB)?
A: The dB scale compresses the wide dynamic range of optical powers into manageable numbers.

Q5: How often should PER be measured?
A: Regular measurements are recommended, especially when temperature changes occur or after fiber handling.