Ruby Emission in the Range 400–800 nm with Excitation by Continuous-Wave CO2 Laser Pulses

Abstract

Thermal emission spectra of ruby single crystals in the range 400–800 nm were studied experimentally as functions of the intensity at 10.6 μm of exciting pulses (~0.5 s) from a continuous-wave electrical-discharge CO2 laser. Spectra at excitation intensity 1–20 kW/cm2 were superpositions of the thermal emission continuum of the sapphire crystal lattice in the range 600–800 nm and selective emission spectra of Cr3+ that were observed for the first time for ruby and consisted of R-lines at 695 nm; N-lines at 715 nm; 2 T 1, 4 T 2 → 4 A 2 transition bands at ~672 and 643 nm; and 4 T 1, 2 T 2 → 4 A 2 transition bands at ~530 and 490 nm that were not observed in the luminescence spectrum. Time dependences of the shapes of selective emission spectra, quenching and shifts of the R 1 line, and the temperature dependence of ruby luminescence spectra were investigated.