We present an optically pumped vertical external cavity surface emitting laser using the semiconductor gain chip composed of quantum wells. With a semiconductor saturable absorber mirror (SESAM), we obtained a Q-switched-like pulse output. The output power reached more than 3 mW at a center wavelength of 1007nm whose repetition frequency was 100 kHz and time bandwidth was 500ns. We discussed the possible reasons that the output power was lower compared with the CW operation. We also investigated the relationship between the intra-cavity intensity and the output pulse width. By designing the gain chip more carefully and increasing the pump power, it should be possible to obtain entirely mode-locking operation.
In this paper, we report a diode end pumped laser with a Yb<sup>3+</sup>-doped Ca<sub>4</sub>GdO(BO<sub>3</sub>)<sub>3</sub> crystal (Yb:GdCOB). The
dopant concentration of the crystal was 7%. The crystal was pumped longitudinally at 976nm by a fiber-coupled
diode laser. The maximum output power of the laser emitted at 1.055um was 430mW, and the laser slope efficiency
was 75% with respect to the absorbed pump power. We also observed that the output power still increased when the
crystal no longer absorbed more pumped power (the crystal had been saturated). The possible reason may be that the
thermal lens effect changed the distribution of the laser mode. This will be discussed in part 3.
We present an optically pumped vertical external cavity surface emitting lasers using the semiconductor gain chip composed of quantum wells. The dependence of the spectrum of the output on the temperature of the gain chip was measured. The maximum output power reached 40mW at the wavelength of 1015.5nm with the pump power of 1.5W. The optical conversion efficiency reached 2.7%.