## About Coherence Length Calculator (Formula)

The Coherence Length (COL) is a concept in optics and wave physics that measures the spatial extent over which a wave remains coherent. In other words, it’s the length over which the phase of a wave remains relatively constant. It’s commonly used in the context of laser light and other sources of coherent light.

The formula used in the Coherence Length Calculator is as follows:

**COL = λ^2 / (2 * Δλ)**

Where:

- COL is the Coherence Length in meters (m).
- λ is the center wavelength of the light source in meters (m).
- Δλ is the total range of wavelengths in meters (m).

In this formula, λ represents the center wavelength of the light source, which is the wavelength at the center of the range of wavelengths emitted by the source. Δλ represents the total range of wavelengths, which is the difference between the longest and shortest wavelengths emitted by the source.

The Coherence Length (COL) is calculated by squaring the center wavelength (λ), and then dividing it by twice the total range of wavelengths (2 * Δλ). The result is the coherence length in meters.

The coherence length is an important parameter in optics and laser physics, as it characterizes the spatial and temporal coherence of a light source. Longer coherence lengths indicate greater coherence and the ability of the light to maintain interference patterns over longer distances.