Continuous wave laser operation of Tm and Ho co-doped CaYAlO4 and CaGdAlO4 crystals

• This paper first demonstrates multi-wavelength lasing operation at 2.0 μm for Tm/Ho:CaYAlO4 and Tm/Ho:CaGdAlO4.
• Single- and multi-wavelength operations of Tm/Ho: CaYAlO4 and Tm/Ho: CaGdAlO4 lasers have been investigated in detail, respectively.
• Red-shift of the emission wavelengths was obviously observed with the increasing of the absorbed pump power.

The growth, spectroscopy and lasing performance of Tm/Ho: CaYAlO4 and Tm/Ho: CaGdAlO4 crystals are reported. The crystal exhibited a broad emission band from 1600 nm to 2200 nm. Single- and multi-wavelength operations of Tm/Ho:CaYAlO4 and Tm/Ho:CaGdAlO4 lasers have been investigated in detail, respectively. The maximum output powers of 376 mW for Tm/Ho:CaGdAlO4 crystal and 582 mW for Tm/Ho:CaYAlO4 crystals have been obtained, respectively. Red-shift of the emission wavelengths was obviously observed with the increasing of the absorbed pump power.