Diffraction Lab Report

Diffraction is the various phenomena that take place when a wave in its advancing path from the source, comes in contact with an obscuring object or a slit. The wave would spread in a defined pattern from the point in which the contact is made (Harutyunyan, 2015). The process involves the bending of light from its incident path through an aperture or obstacle (Nesterets & Gureyev, 2015). When many of the waves pass through slits that are adjacent, there is the chance that there would be an interaction between or among the waves (Antonacci, Di Domenico, Silvestri, DelRe, & Ruocco, 2017).

The result could be a collision to yield interference. Depending on the type of contact made, the interference could be constructive of destructive (Emile & Emile, 2014). The latter joins up the waves to translate to a bigger waveform, but the former often result in the cancellation of the waves. The experiment was a setup of Young’s Double Slit to determine the relationship between y and L defined as the image height and the distance of alignment between the light source and the wall in that order (as shown in the diagram below figure i).

Lambda defines the wavelength of light and d is the distance of separation of the two slits through which the waves spread after coming into contact. With the wavelength of light set at 650nm, the value of y could be determined for the various values of L so that there is the possibility of establishing the linearity relationship and also estimate the angle theta of inclination of the wave.

Figure (i)

From geometry,

tan θ = y/L

y = L tan θ

The angle θ is tiny so that the cosine of θ is approximately 1. Therefore, it could be assumed that tan θ equals sine θ

Y = L sin θ

But sin θ = λ / d where d is the slit separation.

Therefore, y = L λ / d………… Equation (i)

A plot of y against L yields the straight line with the equation y = 0.0046x + 0.3095

Mathematically, the slope of the line is given by λ / d from the equation (i)

λ / d = 0.0046

From the diffraction equation,

d sin θ = λ

λ / d = sin θ

sin θ = 0.0046

θ = sin^-1 0.0046

θ = 0.26^o