aixiz module lens in metal housing

[milantheone]

hello guys

i wonder, is this lens any better than classic plastic one?

seems like it limits some light to be passed through ???? dont know how to describe it.. like plastic ones have not so narrow hole of lens housing on the back side wchich goes to the diode..

https://imgur.com/RZD5PDf

 

[RedCowboy]

G8 will almost certainly be a better lens for most laser diodes, that said why not go with a copper module as well ?

What laser diode will you be using ?

Look at that big opening, oh yea, that's a real mans opening.

 

[milantheone]

G8 will almost certainly be a better lens for most laser diodes, that said why not go with a copper module as well ?

What laser diode will you be using ?

Look at that big opening, oh yea, that's a real mans opening.

thank you for answearing.

i do have some G8 on the way, i am just curious how usable are those metal vs.classic plastic ones. if the smaller opening reduce output too much in aplications where i dont really need g8 and i just need some stock lens.. hence the question if it is better or worse to choose that metal or just plastic..

 

[RedCowboy]

Plastic/acrylic lenses are only useful for low power diodes and you lose a lot more of the power in acrylic as well, there really not much use unless you're selling 5mw lasers and want a cheap lens to keep your costs down.

I don't know what lens is in your metal lens barrel, but I have some that look like it and they have a single element AR coated for red laser diodes, some of them also need a spring to keep the lens from falling out, I usually go by the appearance of the laser beam at night and choose the lens that makes the nicest focused beam and as I like a small far field spot I usually choose a G8, but if you want a small dia, beam up close and don't care as much about the spot size at distance, then you want a G2.

So if you have a low power diode or are driving at low power, then try it and see, but chances are you will like another lens better.

 

[milantheone]

thank you again,,

lets say we realy dont want those acrylic lenses, but as you said keeping the cost down as much as possible and not spending 20bucks for G8.


i am asking because you pointed out that i should consider cooper diode module, and seller have option for cooper + acrylic vs. cooper + glass.
so are glass lensses 400-700nm considered to be an upgrade over acrylic?

thank you

 

[RedCowboy]

Yes single element broadband AR coated aspheric lenses are an upgrade over the acrylic lenses and can be used with a much wider selection of available laser diodes and for outputs of many watts, also acrylic lenses scratch very easily if you try to clean them and they get dirty easily, just smoke in the air from something you burn with your laser can stick to the acrylic lenses easily and detract from your beams appearance causing splatter around your termination/spot.

What matters is focal length, so if you want a glass lens comparable to the typical acrylic you could use a 2 element or a 3 element or a single element mid focal length such as a G3

Our common lenses found in M9x0.5 threaded lens barrels are G8, G7, 3ER, 3EG, 3EB, 2EG, 2EB, G3, G2 and focal length ranges from 8mm for the G8 to 2.39mm for the G2........The 3 element red, green, blue are around 4-5mm focal length IINM but in my testing I have seen some slight variations, also the G3 is mid FL 4-5mm IINM but the G3 is broadband AR coated where as the 3 elements are coated for R, G or B although there were some brodband AR coated 3E lenses but they are not common today that I have seen and 3E lenses lose more power due to internal edge clipping except when used with FAC modified laser diodes.

All this and much more information is available by using the search feature in the top right corner.

 

[milantheone]

Thank you, trust me i have done tons of reading and yet still so much questions pops in my head.

Now i wonder why is focal lenght so important. I understand that it is lens distance from diode, but what impact does it have having lens closer or further.

I would say having shorter distance would give us more power as probably all light goes throught lens.
But clearly there is much more output with somethimg like g8 lens which is long focal lenght thus further from the diode, yet giving more output than shorter FL

Can you please bring some light?

Or does it all depends on divergence of laser diode itself?

Thank you

 

[RedCowboy]

A lens works through refraction, it bends light rays as they pass through causing them to change direction.

All laser diodes are not the same, divergence varies, emitter size varies..... So to compare one lens to another you need to use the same part number diode.

Diodes with wider emitters and more aggressive divergence will experience more edge clipping for a given lens diameter and focal length.

So you can't say that one specific lens will always yield exactly X% more or less power.

That said, typically a short FL lens like our G2 will capture most if not all of the output from most laser diodes, this makes the G2 good for laser diode power testing, that said no lens is 100% efficient, but the G2 is usually about 95% efficient or better.

A longer FL lens like our G8 will vary more as per it's efficiency because of emitter size and divergence, so it's not as easy to assign a typical efficiency due to variables in edge clipping, it's also why the opening is as wide as possible.

p.s. An acrylic is not as efficient as a glass lens not based on only edge clipping, but the material itself is not as efficient at passing light so much so that they will melt if used with more powerful laser diodes.

 

[Hemlock_Mike]

A lens works through refraction, it bends light rays as they pass through causing them to change direction.

All laser diodes are not the same, divergence varies, emitter size varies..... So to compare one lens to another you need to use the same part number diode.

Diodes with wider emitters and more aggressive divergence will experience more edge clipping for a given lens diameter and focal length.

So you can't say that one specific lens will always yield exactly X% more or less power.

That said, typically a short FL lens like our G2 will capture most if not all of the output from most laser diodes, this makes the G2 good for laser diode power testing, that said no lens is 100% efficient, but the G2 is usually about 95% efficient or better.

A longer FL lens like our G8 will vary more as per it's efficiency because of emitter size and divergence, so it's not as easy to assign a typical efficiency due to variables in edge clipping, it's also why the opening is as wide as possible.

p.s. An acrylic is not as efficient as a glass lens not based on only edge clipping, but the material itself is not as efficient at passing light so much so that they will melt if used with more powerful laser diodes.

Red --- You are a true asset to the newbes on the forum. Your answers are most helpful to them.
Keep going !!!!!
HM

 

[paul1598419]

A lens works through refraction, it bends light rays as they pass through causing them to change direction.

All laser diodes are not the same, divergence varies, emitter size varies..... So to compare one lens to another you need to use the same part number diode.

Diodes with wider emitters and more aggressive divergence will experience more edge clipping for a given lens diameter and focal length.

So you can't say that one specific lens will always yield exactly X% more or less power.

That said, typically a short FL lens like our G2 will capture most if not all of the output from most laser diodes, this makes the G2 good for laser diode power testing, that said no lens is 100% efficient, but the G2 is usually about 95% efficient or better.

A longer FL lens like our G8 will vary more as per it's efficiency because of emitter size and divergence, so it's not as easy to assign a typical efficiency due to variables in edge clipping, it's also why the opening is as wide as possible.

p.s. An acrylic is not as efficient as a glass lens not based on only edge clipping, but the material itself is not as efficient at passing light so much so that they will melt if used with more powerful laser diodes.

Acrylic lenses have been able to limit or, in some cases, remove the rectangular artifact seen on some of the lower power newer wavelength laser diodes like the 505nm diodes and shorter wavelength diodes.