Optical Alignment Lab
In this lab, we were tasked to build several simple optical devices to test and develop alignment skills while using the optical lab bench equipment. The devices started off with in detail diagrams and instructions, getting more vague and difficult as the task went on.
Part 1 - Align a Laser
The goal of this part of the lab was to have a laser be reflected 180° by two mounted mirrors and pass through the pinholes of two irises ~20in apart.
Part 2 - Measure Beam Width
The goal of this part of the lab was to measure the width of the laser by reflecting it 180° off of two mounted lasers, passing through an iris, and into a sensor (power meter). The beam was reflected into the laser, with the iris aiding in keeping only the laser and no harsh reflections from entering the sensor. A razor blade set up on a micrometer stand was used to "cut" the beam, allowing for the beam's width to be decreased ever so slightly as we adjusted the stand.
Our data had suggested that the beam was Gaussian, so we took the derivative of the data and displayed it in a graph to find the width.
As the beam was Gaussian, we were able to use our newly found width and find the angle of divergence using the calculations seen above.
Part 3 - Install a Telescope
The goal of this part was to increase the beam width and collimate the beam using a telescope. This was done using the Keplerian Design, having two convex lenses. The lenses were placed at a distance of f1+f2.
Part 4 - Align an Optical Device
The goal of this part of the lab was to build a system with very little information. We had chosen to do the Beam expander with a diverging lens.