# Introduction

The purpose of this page is to build a Mach-Zehnder Interferometer (MZI).

# Laser beam

## Laser

• Laser He-Ne 16 mW.
• mounted on a XY stage to center the beam.

## Custom beam expander

### Optics

Lens 1, version 1:

Lens 1, version 2 (90$): Lens 1, version 3 (130$):

Lens 2:

### Pinhole

About the choice of the pinhole:

Explanations from Newport or thorlabs

$D_o = F \lambda/a$

where F = focal, lambda = wavelength, a = initial diameter). Here, we have F = 18.5mm; lambda = 632 nm; a = 1mm gives 12µm. Thorlabs recommend 30% higher. So, 15 µm.

# Interferometer

2 mirrors:

First beam splitter (where the beam comes out):

Second beam splitter (where the beam comes in):

# Acknowledgements

• We thank Pierre Colinet for suggesting the MZI.
• We thank Irène Wang and Joseph Gallagher for helping us to make the best choice for the various optical components presented here.
• This page has been realized by François Ingremeau and François Boulogne.