Whispering gallery mode resonators: An alternate platform for Ti:sapphire lasers and amplifiers

Titanium doped sapphire (Ti:sapphire) is a ubiquitous gain medium. Due to its broadband gain it has been in use in the solid state laser industry for over three decades while still going strong. We recently demonstrated a Ti:sapphire laser using the whispering gallery mode (WGM) resonator platform. Here, we review some of our previous work, shedding light on the theoretical and experimental lasing threshold of this first high quality Ti:sapphire WGM laser and review amplification with this new platform as well. We also report on new results of multi-mode lasing observed with this system. These results can potentially be utilised in future to train neural networks to control the experimental parameters used to observe lasing.