Principle

With the aid of two mirrors in a Michelson arrangement, light is brought to interference. While moving one of the mirrors, the alteration in the interference pattern is observed and the wave length of the laser light determined.

Benefits

• Learn about the measurement principle with which gravitational waves can be observed
• Assemble your own interferometer using individual optical components
• Find out that even lasers have limited coherence length

Tasks

1. Construction of a Michelson interferometer using separate components.
2. The interferometer is used to determine the wavelength of the laser light.
3. The contrast function K is qualitatively recorded in order to determine the coherence length with it.

Learning objectives

• Interference
• Wavelength
• Diffraction index
• Speed of light
• Phase
• Virtual light source