Lab Demonstration : Michelson Interferometer

Welcome to the laboratory course. My name is Srinivas. I am one of the Teaching Assistants to Introduction to Photonics. Today I will be demonstrating another light phenomena; that is interference so using this Michelson Interferometer. So as we discussed in class the interference primarily, there is 2 things to do with. One is the constructive interference and another is the destructive interference.

You can observe that constructive interference and destructive interference in today's experiment. So first we will build the Michelson Interferometer and then use the Michelson Interferometer to measure the wavelength of the source, the refractive index of the glass slide, the coherence length of the LASER source, and then finally we will see the qualitative understanding

of the spatial coherence of the light source. The first component we use is the LASER source. So this is the red LASER and this is the driver which drives the LASER source. This is the beam splitter which divides the power in two directions, equal power. Two mirrors which are mounted on the kinematic mounts,

mirror 1 and mirror 2. And we use a screen to capture the interference pattern. So we will first construct the Michelson Interferometer and then we will, using this Michelson Interferometer we will calculate the wavelength of the source we are using. And then we will find the refractive index of the glass slide. So this is the glass slide

which has the thickness of 1 point 1 millimeters. So we will find the refractive index of this glass slide using the Michelson Interferometer. And then we will do two more experiments which we will qualitatively understand the importance of temporal coherence and spatial coherence using the Michelson Interferometer. So this is the Michelson Interferometer.