A laser with horizontal polarization is incident on a half-waveplate followed by a a 2nd horizontal polarizer. If θ describes the angle between the slow axis of the waveplate and horizontal, plot the fractional transmission of the 2 nd polarizer vs. θ from 0 to 2π. [ In the Bethel wavemeter, how far in meters do you have to move the sliding mirror in order for the reference laser (i.e. the helium-neon laser) to exhibit 1 full fringe change (e.g. bright to dark to bright again)? For the other laser (the one of unknown wavelength, on loan from the Air Force, and which you had more difficulty visualizing because it looked faint), will moving it this far produce more than 1 fringe, less than 1 fringe, or exactly 1 fringe?