(1) A laser emits 2.68 x 1016 photons per second in a thin circular beam with diameter 1.0 mm. The wavelength of the photons is 532 nm. (a) What color will the laser beam appear to be to the average person? (answer: greenish) (b) What is the laser output power? (answer: 10 mW) (c) What is the intensity of the beam in W/m2? (answer: 1.3 x 104 W/m²) (b) What is the intensity of the beam on a person's retina if the lens of the eye focuses the beam to a circular spot with a 0.1 mm diameter onto the retina? (answer: 1.3 x 106 W/m²)

(1) A laser emits 2.68 x 1016 photons per second in a thin circular beam with diameter 1.0 mm. The wavelength of the photons is 532 nm. (a) What color will the laser beam appear to be to the average person? (answer: greenish) (b) What is the laser output power? (answer: 10 mW) (c) What is the intensity of the beam in W/m2? (answer: 1.3 x 104 W/m²) (b) What is the intensity of the beam on a person's retina if the lens of the eye focuses the beam to a circular spot with a 0.1 mm diameter onto the retina? (answer: 1.3 x 106 W/m²)