In this work, a continuous wave semiconductor diode laser (GaAlAs) which emits radiation at 810 nm and maximum power of 2W has been used to ablate carious enamel and dentine from extracted human teeth in conjunction with specialized diode laser absorbing dye "indocyanine green", and to the best of our knowledge, this study is the first theoretical and experimental study done in Iraq including the possibility of using semiconductor laser for ablation of dental caries.200 extracted human premolars with class II caries and 20 healthy extracted human premolars (patients age range 20-25 years) were collected and chosen as they meet the criteria of sample. The path demonstration and propagation of the laser beam are simulated using MATLAB software version 6.1 supported with visualization technique. An optical arrangement is built up that consisted of the diode laser, collimating lens, focusing lens and attenuator for driving the laser beam into the dyecaries combination. Various laser powers, dye concentrations, and exposure times are used to ablate previously extracted human teeth with class II caries to achieve maximum benefit and minimum side effect. The weight of carious material ablated and the temperature rise in the dental pulp were recorded. The maximum ablation of carious enamel and dentine after 180 seconds of exposure time using 4% ICG dye concentration and 1018.59 W/cm2 laser irradiance was 59.1 mg, which is in good agreement with results of other works. Ablation efficiency and pulp temperature were both found to increase with laser irradiance, exposure time and with the ICG dye concentration. The irradiated teeth surfaces were examined using reflected light microscope and polarized light microscope. A special program was used to examine briefly the ablated carious region of the carious teeth surfaces which capturing its color image using the reflected light microscope. No surface cracks or fissures were seen in microscope examination. Finally the dye-assisted diode laser ablation technique offers selective and efficient ablation with minimal risk of thermal damage to dental pulp and surrounding dental tissues because the uptake of the dye and its irradiation by the diode laser together control the ablation.