- May 28, 2017
No laser diode is better in terms of beam specs, such as Gaussian beam profile or better divergence. This is because the diodes all have an emitter that even in single mode like the LPC-836, which has a pretty good divergence spec, gives a collimated square or rectangular profile when focused to infinity. To get a TEM00 profile you need a gas laser or a DPSS laser like the 473nm or the 532nm.
BTW, you might want to rethink the use of any laser by your very young sisters. No laser over 5 mW is safe to use by children. The problem with the 405nm laser is they are very close to UV and therefore aren't as visible as a 532nm of the same power. In fact, a 80 mW 405nm laser is hardly visible at all.
Okay, so while diode lasers can have some great performance...the DPSS and gas lasers are on an entirely different level in terms of the beams they produce? I still have so much to learn about lasers and will have to go do some reading to understand the difference between single mode, multi-mode, and the impact of optics on them; but out of curiosity-if I understand it right, DPSS lasers have an 808nm diode at it's heart that projects through crystals which is what produces an output in a visible wavelength. So even though it's a diode, do the crystals do something to shape the beam as well and that's why it will have TEM00 performance even though it's still a diode at heart?
I understand, and I have given that some thought which is why I purchased the kids-goggles for them as I could never forgive myself if something happened to their vision. I didn't plan on letting them handle the J/L as those are too powerful for them to handle responsibly... many 18 y/o's and handle those responsibly! Every so often while flying or listening to ATC you can hear pilots reporting being lased and calling out the position to ATC who reports it to law enforcement on the ground. People don't recognize how dangerous that is to a pilot and how critical a pilot's well-adapted night vision itself is to landing a plane safely at night with the already present challenges but that's a whole new can of worms and fortunately it's never happened to me. I like to introduce them to a world outside of the textbooks they read in school and inspire them to want to learn more about the world around them. With your experience, what is a good age you think it's appropriate to begin getting them introduced to using pointers? By that, do you think its safer that they start with something like a 532nm when they do start as they can clearly see where the beam is being pointed and that's part of the problem with the 405nm? I didn't consider that and it makes sense especially if they were to catch something reflective with it unknowingly. I hoped they could be present while doing things with those and would be able to handle the "<5mW" lasers I ordered off eBay to experiment with the glow in the dark stuff (not by themselves though) but I do understand from reading on here that those ebay lasers are almost always over-spec and I am concerned about that. They're 11 and 14 and we've been teaching them firearm safety with .22's for a couple years and thought it may be a safe step to take into lasers under supervision, but if it's recommended to wait till they get older than that's what I'll do. I accept that I'm new to this hobby and there is much in terms of experience and knowledge that I do not know. I appreciate your feedback and pointing that concern and perspective out.