We present novel results on thermocavitation using a CW medium-power near infrared laser (λ=975 nm) focused into a saturated copper nitrate saline solution. Due to the large absorption coefficient at the laser wavelength, the solution can be heated to its superheat limit (T_sh~270-300°C). Superheated water undergoes explosive phase transition around T_sh producing approximately half-hemispheric bubbles (γ~0.5) in close contact with the substrate. We report the temporal dynamic of the cavitation bubble, which is much shorter than previously reported under similar conditions. It was found that the bubble radius and pressure wave amplitude emitted on bubble collapse decreases exponentially with the power laser. Thermocavitation can be a useful tool for the generation of ultrasonic waves and controlled ablation for use in high-resolution lithography.