Final answer:
The question involves laser safety regarding the calculation of photon numbers and power output of a CO2 surgical laser and photon energy of an excimer laser for vision correction, and it compares that energy with the energy needed to vaporize corneal tissue, akin to water.
Step-by-step explanation:
The question pertains to calculating the number of photons and power output of a surgical carbon dioxide laser, as well as the energy of photons from an excimer laser used in vision correction and the energy needed to vaporize corneal tissue.
For the carbon dioxide laser, one would calculate the number of photons based on the energy required to vaporize flesh, assuming it has the same heat of vaporization as water. This involves using the heat of vaporization formula and the energy of a photon given by the equation E = hc/λ, where h is Planck's constant, c is the speed of light, and λ is the wavelength.
For the excimer laser, the photon energy is calculated using the same E = hc/λ equation and compared with the energy needed per water molecule to vaporize, calculated by dividing the heat of vaporization by the number of molecules in a kilogram of water.
The implications of the photon energy relative to the energy required for the phase change from liquid to gas are then discussed.