No, this is not a fuzzy image of the screen of The Rocky Horror Picture Show or Mick Jagger’s (or anyone’s) lip-print, for that matter. It’s a profile of a laser beam. A not particularly friendly laser beam. A nice beam would be round, and its profile would be a zeroeth order Gaussian, but semiconductor lasers don’t always play nice when it comes to beam profiles. The plan was to send this into a single-mode fiber, and single-mode fibers want that nice round beam, and higher-order modes don’t couple very well.

And it was doing it on purpose, just to make my life difficult.