Laser Spectroscopy Podcast

We look at the principles of operation of prism spectrometers and grating spectrometers and discuss operating characteristics (speed, resolving power, spectral transmission and free spectral range).

We consider the advantages and disadvantages of three classes of photodetectors: photodiodes, photomultiplier tubes and thermal detectors.

We look at several examples of tunable lasers and discuss nonlinear optics as a mechanism to increase the region of the spectrum available from laser sources.

We look at 3-level and 4-level gain systems in laser amplifiers, discuss optical cavities and tuning elements of laser oscillators.

We look at an example of calculating the bond length and bond strength of HCl from a measured mid IR absorption spectrum.

We look at energy levels associated with rotation and vibration of molecular bonds

We look at the Bohr model of the atom and see how it can be used to explain the line spectrum of Hydrogen, and then generalize to other atoms.

We look at an application of our previous quantum treatment of the two-level atom for measuring G the universal gravitational constant.

We look at absorption as a quantum effect and introduce the Einstein A and B coefficients for stimulated and spontaneous emission.

We use the classical electron oscillator model to derive the functional form of the index of refraction in material as well as the absorption, which we relate to the cross section.