Why do Infrared LEDs come with different coloured lenses?
I have seen that IR LEDs come with (at least) three distinctly different coloured lenses, namely "Crystal Clear", "Blue" and "Black" ...Using Google, I can find no information about the difference made by the colour of the lens.
So my question is: Why do Infrared LEDs come with different coloured lenses?
Hi,
maybe just a taste...
Even visible LEDs come with crystal clear or colored lenses.
--> I′d rely on the technical informations like wavelength, intensitiy, intensity distribution vs angle, operating current, case size...
Or non technical parameters, like availabilitiy, price...
Klaus
IF your eyes only worked in the IR spectrum, those lenses would ALL look like the same color to you: Clear
It would make no sense at all to have a dark and another transparent len, knowing that the darker one in theory would have the effect of a flat attenuation, though normally in the IR wavelenght things work differently (eg. the darker could be effectivelly 'transparent' for IR). Even knowing the lens color could really impact on the transmitted light spectrum, I tend to believe that these colors are more related to some aesthetic aspect, since this LED is the outermost device of the remote control and could harmonize with different styles/colors of mechanical layouts, otherwise the spectrum of each option would be more evident on datasheet. In short, perhaps there is a negligible change on the light bandwidth's shape for the IR spectrum.
LEDs are essentially monochromatic sources and IR LEDs are no exception.
Whatever may be the reason for the color of the lens, they are all transparent at the IR wavelength concerned.
For example, you can get a red LED in transparent or red package; the red package is convenient for manual assembly but the color of the plastic package has little to do with the LED light. If the package is transparent, you cannot figure it out the color of the light produced without trying it out.