How is temporal coherence key of characteristics of laser?
Temporal coherence:
This coherence is a measure of the correlation among the phases of a light wave at various points along the direction of propagation. This coherence tells us what and how monochromatic a source is.
Measurement of temporal coherence in terms of coherent time is as follows:
Coherent time = Coherent length/ Velocity of light.
There coherent time is the indication of the total time in that the wave passing from any point is continuous.