Consider an experiment using a high energy beam from a nd: yag laser, specifically the 3rd harmonic (uv light) output at 355 nm. the pulse energy is 150 mj, the pulse duration is 7 ns, and the repetition rate is 10 hz (meaning the laser "fires" 10 times per second at equal spacings).
a) what is the peak power of the laser? (peak power refers to the power during the time the pulse is on.) b) what is the average power of the laser? (over many pulses, e. g. over 1 second.)
c) the linewidth of a laser refers to the wavelength range that contains the light. (lasers are nearly "pure colors" which would mean a linedwidth of zero, but in fact they have a finite non-zero linewidth.) assume the linewidth of the laser in this problem is 0.02 nm, and that the beam has an area of 0.3 cm2. the spectral intensity refers to the (peak) power per area per wavelength (where wavelength refers to the wavelength range containing the light, so for a laser it is the linewidth.)
-compute the spectral brightness of the laser pulses in (w/cm2/nm).
-convert the spectral brightness to units of (w/m2/mm). compare this value to that for the sun at 532 nm (see handout from introduction lecture). you should find that the laser has much more light per area at the given (small) wavelength region.
d) assume the laser is perfectly linearly polarized and that a polarizer is positioned in the beam path. the polarizer is rotated to reject light going through it. the polarizer has an extinction ratio of 10,000, meaning that it "leaks" 1/10,000 of the light power in its null position. for a single pulse, how much energy is transmitted through the polarizer?