A high power conical refraction (CR) laser was demonstrated based on Yb:CALGO laser crystal with a separate intracavity CR element. The CR laser delivered the maximum output power of 6.25 W at 25 W of incident pump power which is the highest output power for the CR lasers to date. The separation of the CR element from the laser gain medium reduced the complexity of laser pumping. The generated CR laser beam exhibited excellent quality with well-resolved concentric rings and the Poggendorff dark ring.
A continuous-wave dual-wavelength Yb:CALGO laser has been demonstrated using a 12-mm thick off-surface axis birefringent filter. The obtained wavelength spacing could be tuned from a few nm up to tens of nm. In the experiments ~7.5 W of output power was obtained for 25 W of the incident pump power.
Demonstration of intracavity loss measurement in a diode-pumped continuous-wave Yb:CALGO laser is presented. The characterization method was based on spectroscopic gain measurements and allowed accurate and reliable determination of intracavity losses above the laser threshold. A comparison with traditional Findlay-Clay analysis was also made and highlighted the advantages of the spectroscopic method.
An optimized design of a birefringent filter with an off-plane optical axis is presented to enable multi-wavelength operation of diode-pumped Yb-ion solid-state lasers. The simulation results indicate that such birefringent filters can be used for the development of powerful tunable multi-wavelength Yb-ion laser sources. A comparison with performance of a standard birefringent filter that has its optical axis lying in plane of a plate is also given.