Every point on the wave surface is a wave source that emits a wavelet, and the envelope of the wavelet is the new wave front.

Each wavelet has the same initial phase

Wavelet phase at point P

The amplitude of the wavelet at point P

The vibration of any point P in space is the result of the coherent superposition of vibrations caused by all wavelets at that point.

Fresnel diffraction

Fraunhofer diffraction

Maximum optical path difference

stripe angle width

Light intensity distribution

Move the position of the single seam up and down, and the position of the central plain pattern remains unchanged.

Rayleigh criterion:

Resolution:

a: Width of the translucent (or reflective) part

b: Width of the opaque (or non-reflective) part

Ming pattern (main Ming pattern, main maximum) thin and bright

There is a gradation phenomenon

Single-slit diffraction affects multi-slit interference

The optical path difference is

The main level large clear pattern coincides with the single slit diffraction dark pattern

grating main clear pattern

Single seam dark pattern

Clear patterns of different colors are arranged according to wavelength to present colored light bands - chromatography

White light incident

Asymmetrical to the direction of propagation

Symmetrical to the direction of propagation

natural light incident

linearly polarized light incident

Normally

satisfy

brewster point