Huygens wave theory:
Huygen's wave theory is not correct in all respects.
2. It assumes simply that light energy is propagated as a wave.
3. At the time of his proposition Huygen's did not have any idea about wavelength or about the transverse nature of light.
4. So Huygens wave theory was Later modified by Thomas Young and Fresnel.
5. They introduced the concept of wavelength and assumed that light waves are transverse.
6. By these assumptions they could successfully explain not only the rectilinear propagation of light but also the phenomena of interference, diffraction and polarization of light.