Diode Laser Spectroscopy
Introduction
The diode laser spectroscopy experiment is a fantastic introduction to atomic physics. Students will learn the basics of diode laser operation and measure the spectrum of Rubidium with it’s two naturally occurring isotopes. This experiment is great for students interested in applied optics and photonics, and precision atomic physics.
Please see the recorded video here.
The manual is available here, and is available in the lab in two separate binders. The manual has 6 sections:
- Introduction to Diode Lasers
- Diode Laser Spectroscopy
- Initial Setup & Explorations
- Experiments
- Apparatus Specifications
- Appendix: Set-Up Instructions
Section 1 is useful information about the semiconductor diode laser you will use in the lab and the external cavity that is set up to achieve a narrow frequency range. This info isn’t completely necessary for you to do the experiment, but you can read it if you are interested in semiconductor diode laser physics.
Section 2 explains the basics of the types of spectroscopy that you will do in the lab, and has figures that show what your spectroscopy signal will look like. Page 2-8 has incredibly relevant figures.
Section 3 explains the working of the apparatus and its control knobs, and how to do the initial alignment of the laser. The apparatus will be poorly set up for the Doppler-broadened spectroscopy experiment (as in Figure 12). You certainly don’t have to change anything about the external cavity. You should end up with data like in Figure 14. Section 3-III explains the saturated absorption set up and data. Section 3-IV discusses how to set up a Michelson interferometer, which is information you won’t need.
The rest of the manual has reference experiments for the spectroscopy you will do and some potential extension experiments you could do if you were very interested in this experiment or had a term project to do or something.
The instrument that controls this experiment has a million knobs. Figure 1 shows where the most relevant ones are and what they do.
Figure 1: Diode Laser Spectroscopy control box.