Measurement of the room temperture R(1) line width of forty-two rubies.

Accurate measurement of the room temperature R(1) fluorescent line width of forty-two ruby laser crystals has been made using a pressure-scanned Fabry-Perot etalon. In forty-one of these rubies the chromium content was nearly the same, and the R(1) line width for all was 5.0 +/- 0.3 A, in agreement with present theories.