Question

How do you obtain coherent sources?

Answer 1

Step 1: Explanation

1. The frequency of a sinusoidal wave is defined as the number of complete oscillations produced by any wave constituent per unit of time. According to the definition of frequency, if a body is in periodic motion, it has completed one cycle after passing through a series of events or locations and returning to its original condition. Thus, frequency describes the rate of oscillation and vibration.
2. Wavefront division, in which the wavefront is divided into two or more sections using mirrors, lenses, and prisms. Young's double slit arrangement, Fresnel's biprism approach, Lloyd's mirror method, and others are common methods.

Step 2: Draw diagrams showing Fresnel's biprism and Lloyd's mirror respectively

and

Therefore,

1. In physics, two wave sources are coherent if their frequency and waveform are the same and their phase difference is constant.
2. Two waves are termed coherent if their relative phase remains constant.
3. Two sources are said to be coherent if the waves produced by them have the same frequency and a continuous phase difference.
4. Interference from such waves occurs all the time; at some point, the spontaneously phased light waves continuously form bright and dark edges.
5. Coherence is a fixed relationship between waves of a particular frequency phase in a radiation beam.
6. Two beams of light are coherent when the phase difference between their waves is constant; they are non-coherent when there is a spontaneous or fluctuating phase connection.
7. Division of amplitude occurs when the incoming beam's amplitude is divided into two or more pieces by partial reflection or refraction as shown in the diagram. These split pieces travel down distinct courses before reuniting to cause interference. For example, Newton's rings, Michelson's interferometer, and so on.

Hence, this is the way to obtain coherent sources.