Balmer Series

Video tour
Experiment Guide
1.  Pre-Lab
2.  Guide
3.  Software Manual
4.  Lock-in Intro

Related Material
1.  Melissinos (2003) pp25-33, 232-236
2.  Cosmic Deuterium 
3.  Spectrograph
4.  Detector
5.  Why lock-in?
6.  Analog Lock-In manual
Useful Links
1.  Optics of Spectroscopy
2.  Nobel Prize
3.  Harold Urey story
4.  Optics Tutorial









This is an experiment in optical spectroscopy: the accurate determination of the energy of the light quanta emitted by atoms. You will first learn some optics and how a spectrograph works. Then you will rapidly chop the light from the source and learn how to detect faint light by measuring the in-phase component of the chopped light using a photodiode and a lock-in amplifier (one of the experimentalist's most useful and powerful tools for recovering signals otherwise hopelessly buried in noise.) The goal is to study the emission lines of hydrogen and its heavy cousin deuterium.