Square/Rectangular Beam Pattern Optic?

Just as the title says, I'm looking for an optic that can produce a square or rectangular beam pattern. I tried googling, but nothing turned up. My question arises over a few concerns, namely: that all of the high quality LED off road lighting for vehicles seems to be coming from VisionX. I am concerned about this, as well as the high price of these units. So, I am considering making my own LED off road lights, and would prefer a square or rectangular beam output. Thank you in advance for any comments or suggestions.

search for "wide angle" optics

This is a 52mm lens that will fit into a standard maglite head from DX. Basically any lens that looks like this (with ridges along one direction) will be a "line generating" optic, rather than a "point" generating It is an aspheric lens that projects a line, rather than a bright point. However, if you de-focus the optic (eg, position the optic closer to the LED than the actual focal point) you will end up with a broad rectangular pattern, similar to HID projector headlights.

I'm using a neutral-white Cree-MCE behind one of these lenses as my primary bike light. Again, a quad die LED will transform the output from "thin line" to more like square/rectangular beam profile you're looking for.

Ledil make XXX-REC optics which are 22x11 degree type shapes, the xxx refers to the type relative to the Led you choose or as 2XT suggests an aspheric lens will typically project the led die which will be kinda square/oblong

Ledil also has oval series, look at www.ledil.fi
Carlco also hase rectangular and oval series.

I don't understand, how do you google.