Absorption and Fluorescence of Ruby Crystal

The unique optical properties of the ruby crystal that make it effective as a lasing medium were measured using a simple optical setup.Ruby's absorption of visible light was shown to be strongest at 420 and 550 nm, corresponding to its physical appearance as transparent pink.While the ruby crystal was illuminated with a 532 nm green laser, the R-line fluorescence peaked at 693.5 1.1 nm.Finally, the fluorescence lifetime of ruby was measured by pulsing the laser with a signal generator and capturing the decaying fluorescence on a digital oscilloscope using a photodiode.An exponential decay time-constant of 3.6 0.1 ms was obtained, corresponding to the fluorescence lifetime.