Small LED's cannot provide enough light for general Fiber optic lighting

by Michael Groves
Many people ask if they can use a regular LED to light fiber optics.  The answer is yes if you only want a pin point of light at the end of a fiber.  However, this will not enable the lighting of buildings or street lights.  
 
  
 
Why is this? 
A typical 20mA LED puts out about 10 lumens beamed out over 135 degrees from the lens. The LED light itself is typically about 5mm from the surface of the lens.  At this small distance, the beam covers an area of 460 sq.mm.
 
 A 1.5mm fiber has a surface area of 1.8 sq.mm .  Hence, a 1.5mm fiber can only pick up 0.4% of the light (1.8 divided by 460).  In terms of light collection from a 10 lumen light source, this amounts to 0.04 lumens.
The Lamplighter™ Box puts out 200+ lumens which is collimated through internal optics into a 6mm diameter beam, which has a corresponding surface area of 32 sq.mm.  Again, taking the 1.5 fiber, the light collection would be 5.5% (1.8 divided by 32).  Again, in terms of light collection from the Lamplighter box,  this amounts to 10 lumens of light collection.
 
This is 250 times brighter than one can get from a 20mA LED going into a single fiber!
On top of this, a single  single fiber provides as much light as a single 20mA LED, but without any wiring.  Now that's just one of the benefits of the Dwarvin system.
 
You can see from this calculation why I quickly abandoned using 20mA LED for this product.

Leave a comment

Please note, comments must be approved before they are published

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.