Q3Engineering Physics
Question
2 marks
Population inversion.
Answer
Spatial coherence refers to phase correlation across different points in space, while temporal coherence refers to phase correlation over a period of time at a single point.
- Spatial Coherence (Transverse Coherence): It is the measure of the correlation between the phases of a light wave at different points in space along a wavefront at the same time. It determines the directionality of the beam.
- Temporal Coherence (Longitudinal Coherence): It is the measure of the correlation between the phases of a light wave at a single point in space over a certain time interval. It determines the monochromaticity (spectral purity) of the source.