Question

1. Find the power of a laser, if the irradiance is 1500w/cm²and all the laser's output power is focused on a circular spot with a 16um (micrometer) diameter

a.		0.0042watts or 4.02mw
b.		0.0062watts or 6.02mw
c.		0.0032watts or 3.02mw
d.		0.0082watts or 8.02mw

2. Consider a pupil opening 5mm (0.5cm) in diameter. What is the maximum HeNe power allowed for a 0.25second exposure? (By exposure, we mean looking directly into the beam-intrabeam viewing or directly viewing a specular reflection of the beam). Use the MPE chart

a.		3.2mW
b.		0.54mW
c.		0.5mW
d.		0.49mW

3. what is the speed of the wave with amplitude a=0.15m, wavelength=0.80m, frequency=0.5Hz

a.		0.2m/s
b.		0.80m/s
c.		0.5m/s
d.		0.4m/s

Answer 1