BeamBreak LED wavelength?

Greetings! I am trying to find any information about the wavelength of the adafruit beambreak:

Specifically, what wavelength of LED is used in the emitter? I have checked all of the data sheets and I can not find any answer. Thank you!

I have sent a request to the Product Manager

Hi sojf9j,

It wouldn’t surprise me if we do not get a definitive answer on this, due to the lack of information on the datasheet. However, almost all similar products have wavelengths between 850 and 940nm.

Is there a particular reason you need to know the specific wavelength, considering that it comes with matching emitter and detector?

Hi guys! Thanks for the fast responses!

The reason I am asking, is that I have had several emitters burn out on these beambreaks over the course of a few years, and I am hoping I could just swap in a replacement LED of the same wavelength, or purchase a higher quality LED that would not burn out.

I’ve been struggling to find any comparably priced beambreak solution in the ~5v range but any suggestions are welcome.


There are a few things to consider. First, these are inexpensive for a reason. They are not like your typical Panasonic or Omron type devices. If you are powering these with 5V, it may be pushing the limits of what the emitter can handle. Dropping that voltage a bit might yield better results. You might want to check the actual current draw to get an idea what it is drawing.

As far as trying a different emitter, anything that physically fits will probably give reasonable results. Almost all IR phototransistors will detect over a relatively broad range of wavelengths. If they are optimized for a different wavelength, you may lose as much as 30% sensitivity, but it will likely still function at close to the same range. If you get a few in the 880nm and a few in the 940nm range and experiment, you can probably find one that will do as well. Just check that you are not exceeding the manufacturer’s max current specs.

Keep in mind that viewing angle will have a significant effect on performance. Wide angle will be more forgiving for alignment, but will have a shorter range for a given output power. Here’s a starting point if you decide to try replacing the emitter.

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Ditto Dave on the “low cost for a reason” sentiment, adding that the possibility of an ESD or power supply issue could also be a cause of problems.

I’d suggest the SFH 4555. Nice narrow angle, good intensity…

@David_1528 @rick_1976
Thanks so much for your advice guys! I went with a 12V Panasonic option for ~$100. I’m quite sure that it will yield an improvement in reliability over the $6 solution :slight_smile:

I think the extra cost will be more than justified by not having to keep replacing the emitter.