Optical Zeeman effect in the R1 and R2 lines of Mn4+ in Al2O3

Hans Riesen, Thomas Monks-Corrigan, Neil B. Manson

S.P. Feofilov, A.B. Kulinkin, A. B. Kutsenko +1 more

S. Nakayama, George William Series, Wojciech Gawlik

L. M. Kanskaya, Alexander I. Ryskin, Alexandra M. Tkachuk

Roman L. Kolesov

Sharp resonances in optical excitation of ruby by laser pulses are observed as Zeeman sublevels anticross in an external magnetic field. For the ${R}_{1}$ optical line of ruby $(694.3\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$ excitation drops when the external magnetic field strength approaches $4.14\phantom{\rule{0.3em}{0ex}}\mathrm{kG}$ while for the ${R}_{2}$ line $(692.9\phantom{\rule{0.3em}{0ex}}\mathrm{nm})$ it increases in $4.14$ and $2.07\phantom{\rule{0.3em}{0ex}}\mathrm{kG}$ fields. A simple theoretical description of the observed effects on the basis of level mixing explains both situations.

F. J. McClung, S. E. Schwarz, F. J. Meyers

Optical maser action at the R2 line in ruby has been observed. Because of a fast thermal relaxation between the two 2E levels, it is not usually possible to satisfy the maser conditions at the R2 line when stimulated emission is occurring at the R1 line. However, if maser action can be suppressed at the R1 line, even at high inversion, it can be made to occur at the R2 line by the appropriate selection of operating conditions. This has been accomplished by using, for end reflectors, multilayer dielectric interference filters which have high transmission at the R1 line and low transmission at the R2 line. The selection of the operating conditions requires a correction of the absorption coefficients for the R1 and R2 lines based on the Boltzmann distribution between the two excited states. When the Boltzmann correction is made, the calculations show reasonable requirements on pumping threshold and reflectivities.