DIY optical fiber night light

Make a cool DIY night light

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion.


  • emp­ty chip con­tain­er;
  • push­pin;
  • op­ti­cal-fiber ca­ble;
  • bat­tery pack;
  • wire con­nec­tor;
  • LED.

Step-by-step in­struc­tions

Care­ful­ly re­move the in­su­la­tion from an op­ti­cal fiber and cut the fiber into small pieces (~ 10 cm / 4 inch­es). Use a push­pin to poke some holes in the lid of a chip con­tain­er and in­sert a piece of the fiber into each hole. Con­nect a bat­tery pack to an LED and place them in the con­tain­er un­der the lid. Your night light is ready!

Process de­scrip­tion

Un­like con­ven­tion­al ca­bles, which em­ploy elec­tri­cal im­puls­es, op­ti­cal ca­bles use light to trans­mit sig­nals. Since light does not re­act to ex­ter­nal elec­tro­mag­net­ic fields, the sig­nal is not dis­tort­ed and data trans­mis­sion is vir­tu­al­ly un­com­pro­mised. In ad­di­tion, op­ti­cal fibers al­low us to di­rect light along a con­ve­nient route. They op­er­ate based on the phe­nom­e­non of to­tal in­ter­nal re­flec­tion – when light moves from an op­ti­cal­ly denser medi­um to a less dense one, at more than a cer­tain an­gle, it re­flects en­tire­ly off their bor­der. To­tal in­ter­nal re­flec­tion min­i­mizes loss­es as the sig­nal is passed along.

More cool ex­per­i­ments are wait­ing for you in the MEL Physics sub­scrip­tion!!