405nm Lens Myths? Or Facts?

[meatballofall]

I've been reading this forum for awhile now, and I'm new to this forum as a member. I'm working on a 110ma PHR-803t Dorcy Jr. Build. But when it's come to lenses, posts on this website keep saying opposite things, so I thought I would go ahead and just get these facts straightened up here in the 405nm forum since it seems most of the confusion is around this wavelength.

I've heard these and they're opposites... lets debunk them as either myths, or facts.

-Glass lenses reflect the 405nm wavelenth back towards the diode, slowly damaging it.

-Glass Lenses are AR (?) coated, which results in an optical power loss.

-Glass Lenses can give a Laser a +/- 10% power difference.


What are the factors that lead people to say these things? Which of these things are true? And which are irrelevant to a 405nm build? Post sources/charts/tables/graph if you can. Anything else I should know about the differences between acrylic lenses and glass ones? Feel free to share!

 

[daguin]

It depends on which "glass lens" you are talking about. The stock AixiZ glass lens is bad for the violet laser because of the first two things you have listed. However, the Merideth glass lens and the two custom glass lenses being sold right now in this forum are up to 28% better for the violet laser

Peace,
dave

 

[pseudolobster]

AR coating = Anti-Reflective coating, which is designed to minimize reflections for a certain wavelength of light. It happens that the AR coating on aixiz glass lenses is made for red lasers, and actually increases reflections for violet lasers.
The new custom glass lenses that people are making are AR coated for violet, making them better than uncoated lenses, and much better than lenses AR coated for red.

 

[jayrob]

I've been reading this forum for awhile now, and I'm new to this forum as a member. I'm working on a 110ma PHR-803t Dorcy Jr. Build. But when it's come to lenses, posts on this website keep saying opposite things, so I thought I would go ahead and just get these facts straightened up here in the 405nm forum since it seems most of the confusion is around this wavelength.

I've heard these and they're opposites... lets debunk them as either myths, or facts.

-Glass lenses reflect the 405nm wavelenth back towards the diode, slowly damaging it.

-Glass Lenses are AR (?) coated, which results in an optical power loss.

-Glass Lenses can give a Laser a +/- 10% power difference.


What are the factors that lead people to say these things? Which of these things are true? And which are irrelevant to a 405nm build? Post sources/charts/tables/graph if you can. Anything else I should know about the differences between acrylic lenses and glass ones? Feel free to share!

Yes, some of the things you heard were true before we had these 405-G-1 glass lenses made specifically for blu-ray!

See here for detailed pictures, measurements, and beam shots:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1237515270
Jay

 

[Krutz]

yes, everything everyone said.
besides: acrylic or glass by itself (with no coating, or the same one) are not that far from each other. for reds they are basically equal. for bluray, acrylics may age faster, while glass shouldnt age at all. acrylics start to absorb violet at a distinct point, which is *near* 405nm, but depends on the acrylic. at 400nm, it should be a huge factor already. the bluray-diodes do vary a bit in wavelength, up to +-5nm.
much more details on this on the huge thread from igor:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1212842385
wait, to sum it up, it is a difference between acrylic and glass for bluray!
the right/wrong ar coating is an even larger factor.
after reading the first few pages from igor's thread you should know mostly anything about lenses for bluray

manuel

 

[meatballofall]

hey thank you much! This is all great information! I really appreciate it!

TT