Efficient continuous wave and broad tunable lasers with the Tm:GdScO3 crystal

Spectroscopy and Kerr-lens mode-locked operation of Yb:GdScO3 crystal

A Kerr-lens mode-locked laser based on a Yb3+-doped disordered gadolinium scandate (Yb:GdScO3) crystal is reported for the first time, to the best of our knowledge. The crystal with the perovskite structure was grown using the Czochralski method, and its room temperature (RT) and low temperature (LT) spectra were also investigated. Due to the crystal's multisite structure (Gd3+/Sc3+ site), Yb:GdScO3 offers broad and intense polarized emission spectra in the near-infrared range (975-1075 nm). The stimulated emission cross section σSE is 0.46 × 10-20 cm2 at 1000 nm with an emission band width of 75.7 nm for E // b polarization. The continuous wave (CW) laser was operated pumped by a 976 nm fiber-coupled LD laser, resulting in a maximum output power of 8.74 W with a slope efficiency of 76.1% was obtained. Additionally, a pulses as short as 74 fs are generated at ∼1061.7 nm via Kerr-lens mode-locking. The average output power amounts to 32 mW at a pulse repetition rate of 101.4 MHz. All results indicate Yb:GdScO3 a promising candidate for 1 µm ultrashort laser.

Tunable and mode-locked Tm,Ho:GdScO3 laser

A novel, to the best of our knowledge, Tm,Ho:GdScO3 crystal grown using the Czochralski method was investigated for its polarized spectroscopic properties and laser performance in both tunable continuous-wave (CW) and mode-locked regimes. The crystal's multisite structure (Gd3+/Sc3+ site) and Tm3+/Ho3+ dopants contributed to spectral broadening, enabling a tunable laser operation from 1914 to 2125 nm (with a broad range of 215 nm). Additionally, a pulse duration of 72 fs was achieved for E || b polarization. These results demonstrate the potential of the Tm,Ho:GdScO3 perovskite crystal as a promising gain material for ultrafast lasers operating around 2 µm.

SESAM mode-locked Yb:GdScO3 laser

We report on the investigation of continuous-wave (CW) and SEmiconductor Saturable Absorber Mirror (SESAM) mode-locked operation of a Yb:GdScO3 laser. Using a single-transverse-mode, fiber-coupled InGaAs laser diode at 976 nm as a pump source, the Yb:GdScO3 laser delivers 343 mW output power at 1062 nm in the CW regime, which corresponds to a slope efficiency of 52%. Continuous tuning is possible across a wavelength range of 84 nm (1027-1111 nm). Using a commercial SESAM to initiate mode-locking and stabilize soliton-type pulse shaping, the Yb:GdScO3 laser produces pulses as short as 42 fs at 1065.9 nm, with an average output power of 40 mW at 66.89 MHz. To the best of our knowledge, this is the first demonstration of passively mode-locking with Yb:GdScO3 crystal.

44-fs pulse generation at 2.05 µm from a SESAM mode-locked Tm:GdScO3 laser

Pulses as short as 44 fs (6 optical cycles) with a spectral width of 120 nm are generated from a mode-locked solid-state laser near 2 µm employing an orthorhombic Tm:GdScO₃ perovskite crystal. The average power amounts to 188 mW at a repetition rate of ∼77.6 MHz. The strong inhomogeneous line broadening in GdScO₃ suggests optimum conditions for few-optical-cycle pulse generation of rare-earth ion doped GdScO₃ bulk lasers.