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1. The energy of a photon depends on its frequency. Higher-frequency photons (toward ultraviolet) have more energy than lower-frequency photons (toward the infrared range).
2. Stimulated emission is the basis of laser phenomena. Stimulated emission creates a chain reaction leading to the creation of many photons of the same energy.
3. The biomedical application of laser light involves its ability to focus intense energy in a small area. Focus is determined by monochromicity, collimation, and phase synchrony, all of which are superior in laser light than in ordinary light.
4. CO₂ lasers pose a high risk of remote fires. CO₂ laser light is invisible infrared and usually transmitted to the surgical site in a beam through free air.
5. KTP-type lasers are not usually transmitted through air. These lasers are conducted by fiberoptics to a direct contact tip that creates heat from light, coagulating adjacent tissue.
6. Infrared laser light at 10.6 µm is strongly absorbed by water molecules. This frequency of laser light, generated by CO₂ laser, explosively converts water to steam.
7. Different laser sources require different eye protection. Any glass or plastic lens can block CO₂ laser light, but other lasers require type-specific protection.
8. All nonmetal endotracheal tubes have the potential to burn in the airway.
9. Nitrous oxide should not be used to dilute the FIO₂ during airway surgery. Nitrous oxide supports combustion just like oxygen.
10. If possible the FIO₂ should be held below 40% during airway surgery.