Lasers using the sun as a pump source are highly efficient (compared to electrically pumped lasers) and powerful (easily reaching multi (or mega) watt cw output). They usually use a lens assembly to focus sunlight onto a gain rod like Nd:YAG to create a population inversion. Solar pumped lasers are good for use off the grid (like in space), or when very high power/temperature outputs are needed (like in magnesium energy conversion).
It obviously wouldn't be very practical to break an efficiency or power record in the LTC, so I'm trying to think of what I could/would be able to try with a solar pumped laser.
Ultrashort pulses of light interest me because of my experiences in an ultrafast spectroscopy lab. How can one modelock a basic HeNe laser?
This undergraduate thesis and Ewuin's work in the LTC will be helpful resources.
Many feature films are shot in the anamorphic format. The anamorphic format is a technique in which a widescreen image is shot on standard non-widescreen film by stretching the vertical axis of the frame. This is done using special anamorphic cinema lenses. When projected in the theater, the vertical axis is compressed using another lens such that a widescreen, undistorted image is displayed. Nowadays (in the digital age), the image is digitized from the film, then compressed using software.
Anamorphic films have a few distinct characteristics. The circles of confusion (bokeh) are elliptical rather than circular. Lens flare from point sources creates horizontal lines that span across the entire frame.
A regular rectilinear lens produces circular circles of confusion (bokeh).
An anamorphic lens produces elliptical circles (ellipses?) of confusion.
Anamorphic lens flare.
Shooting in the anamorphic format requires very expensive anamorphic lenses. How can one attain the characteristics of the anamorphic format without using such expensive optics?