Enter the center of the range of wavelengths and the total range of the wavelengths into the Coherence Length Calculator. The calculator will evaluate the Coherence Length.

## Coherence Length Formula

The following two example problems outline the steps and information needed to calculate the Coherence Length.

COL = λ^2 / (2*dλ)

• Where COL is the Coherence Length ( )
• λ is the center of the range of wavelengths
• dλ is the total range of the wavelengths

## How to Calculate Coherence Length?

The following example problems outline how to calculate Coherence Length.

Example Problem #1:

1. First, determine the center of the range of wavelengths.
• The center of the range of wavelengths is given as: 3.
2. Next, determine the total range of the wavelengths.
• The total range of the wavelengths is provided as: 4.
3. Finally, calculate the Coherence Length using the equation above:

COL = λ^2 / 2*dλ

The values provided above are inserted into the equation below and computed.

COL = 3^2 / (2*4) = 1.125

Example Problem #2:

For this problem, the variables required are provided below:

center of the range of wavelengths = 10

total range of the wavelengths = 20