Hi John,
Thanks for contacting me about this.
All of the RPLs both green and blue have optical coatings which block IR, they do not have seperate filters. This is much better way to remove any stray IR, but is more expensive than using seperate filter. The reason this is better is that each additional surface that the beam has to go through degrades beam quality (especially with the very cheap filters that are commonly used). This causes more scatter and a larger beam. Also each surface even if multicoated will lose anywhere from 3-6% of the light through absorption, so eliminating stray IR by the use of coating on optical surfaces already present.
I have come across a few of the RPL blue lasers whcih for reason in the mfg. process must not have passed the IR tests and an extra filter was placed in them and they still passed all specs, but their power would have been reduced over what it would have been otherwise.
I do know that the older generic viasho protable lasers (and maybe even those made today, but can't say for sure as I've not had my hands on any of them in a couple of years), did not filter for IR.
I personally test each RPL for any IR leakage and any one which emits 1% more of IR to green never goes to a customer and gets reworked. With the premium pens pointers, this is tested and limited to no more than 4% and is typically 3% or less.
Thanks for telling me about this discussion John, I've gotta go now as I'm extremely busy this past few weeks and have an out of town visitor on top of all the work to get done.
