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.

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## 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

To calculate the coherence length, square the center of the range, then divide by 2 times the total range.

## How to Calculate Coherence Length?

The following example problems outline how to calculate Coherence Length.

Example Problem #1:

- First, determine the center of the range of wavelengths.
- The center of the range of wavelengths is given as: 3.

- Next, determine the total range of the wavelengths.
- The total range of the wavelengths is provided as: 4.

- 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

Test your knowledge using the equation and check your answer with the calculator..

COL = λ^2 / 2*dλ** = ?**