Describe what is a Wavefront

A wavefront is a hypothetical surface that represents the corresponding points of a wave that vibrates together synchronously. It is thus described to be the set of locations in a particular plane, where the waveform is propagating across and attains the same phase as that of the vibrations generated upon the medium. It is thus independent of the troughs and crests of the wave. Therefore in such cases, the wavefront is also called the locus of all points that have the same phase.There are several characteristic traits of the wavefront as it proceeds with time and the orientation of the wavefront may even differ over time through diffraction if the propagation of the speed differs at different points.

Wavefront: Locus of all points with same phase

Wavefront is a hypothetical site that vibrates in unison and the wave is in the same phase as it. This condition is irrespective of the state of the wave, whether it is the crest of the wave or the trough. 

There are different types of wavefronts that are determined by the path followed by particles generated from a particular point of source 

• Spherical Wavefront: the wavefronts generated are centred in a source when the point of a source is an isotropic medium that sends out waves in three dimensions. In space, electromagnetic waves exhibit a spherical wavefront. The formation of ripples in a water body exhibits the most prominent of the spherical wavefront. 
• Cylindrical wavefront: When the source of light is following a linear path, a cylindrical wavefront is established. The most prominent example of such a wavefront is noticed when rays of light are incident on one lens coming out of another lens. Those incident rays of light converge at a particular point and it forms a cylinder shape. 
• Plane wavefront: This wavefront exhibits a distinct property of illusion. It will appear as a plane when it is being observed from a considerable range of distance. These wavefronts are formed with the generation of the cylindrical or spherical wavefront from an immeasurable amount of distance. The most common example of the plane wavefront is noted from the incident ray of light from the sun falling upon the surface of the earth.

Source of light: discussion

The objects that generate light are referred to as the sources of light, these sources of light enable the propagation of light that is incident on various surfaces that help us in seeing different objects. The sources of light can be further classified into natural and artificial sources of light. The prime example of a natural source of light is the Sun and the stars, artificial sources of light include candles, tube lights, bulbs, LEDs etc. Light sources can be subdivided into two categories. There are two kinds of wavefronts to be produced depending upon the source of light.

• Point source of light: the wave travel in all directions derives radial and spherical lines of rays
• Linear source of light: the wavefronts are cylindrical for the linear source of light. 

The intensity of light waves: discussion

The intensity of the light waves is dependent upon the aspect of the transmission of light that reaches our eyes. It is determined by the energy of the light transmitted per unit area in a single unit of time. It is derived from the electromagnetic theory that light travels in the form of a wave. The intensity of the wave is directly proportional to the wave amplitude as generated. It is represented by I ∝ A2, where, I = intensity and A= amplitude of wave.

Conclusion

The wavefront is a hypothetical surface that vibrates in unison with the incidence of the wave. This state is noticed in both the crest and the troughs; these wavefronts are further subdivided based on the incident of the impact. It is found in ripple formation in the water body or a ray of light coming down from the sun. There are different sources of light and thus the wavefront differs accordingly. The intensity of the light waves as generated is calculated by the amount of light transmitted per unit area in one particular unit of time.