Unibody Littrow Laser

Steck Lab
Department of Physics
University of Oregon
541.346.5863

Page last updated Nov. 2, 2012

Overview

A Littrow configuration external cavity diode laser. Features include:

In creating this design, we made conscious efforts to optimize the cavity's stability at the expense of simple large-scale tunability. The result is a laser that works well for atomic physics—although we don't have mode-hop-free tuning over much more than 10 GHz, the free-running laser is quite immune to environmental perturbations.

For a more complete description and stability investigations, see our RSI paper.


Assembly Photos

We have photographically detailed and discussed the assembly process here.



Altering cavity length and operating wavelength

The right-angle geometry of our design allows a simple elongation of the Littrow cavity, and we made a short and long version of otherwise identical lasers. Extending the cavity length decreases the white noise contribution to the linewidth (by a factor of the square of the ratio of the lengths), but also decreases the free spectral range of the cavity, substantially reducing the mode-hop-free tunability of the laser. We recommend using the long cavity design only when you desire an unusually narrow linewidth (typical atomic transitions are broader than a few hundred kHz anyway, so it's just not worth the extra headache).

We have successfully constructed lasers at several wavelengths (994, 922, 914, 780, and 689 nm), but the geometry supports an assortment of wavelength ranges. For more information on adapting this design to your particular wavelength, we have made this page.


Machine Drawings

Download a complete set of all materials listed below: (All ZIP)
Note that the Diode Can Mount and Optical Isolator Mounts are identical for the long and short lasers. They are included in both machine drawing sets for convenience.

Peripherals

Components common to both cavity types.