Fiber Optic Light Collimator

I've been playing with DIY spectrophotometers and came up with this as an easy way to improve the fiber optic cable output before passing light through a slit. The cheap lens is far from perfect but works great for it's intended purpose.

Uses a 5mm plastic lens from a cheap $1 laser pointer (650nm, Dollar Tree) to collimate light output from a standard fiber optic audio cable. Paint all interior surfaces black and press the lens (flat side towards fiber optic) into the hole until it sits flush. Test the focus and push the lens deeper into the tube until it forms a sharp circle at any distance. The lens from my laser had a 4mm focal length, but the design can be easily extended as needed.

The female cable connector was taken from GaudiLabs Open Fiber Spectrometer (https://www.gaudi.ch/GaudiLabs/?page_id=825).

Creality

Ender-3 V3 SE

Doesn't Matter

0.3

20