Need information about lens

Hello,

I try to make my own red laser, so I bought a 200mw diode laser and make my driver (LM317) powered by 2 li-ion which works great however I forget the lens...

So can I take out one from a cheaper chinese laser ? If yes what is the distance between the diode and the lens ?(How do I calculat it ?) Is this distance can be fixed or it must be adjustable ?(think adjustable because the theory is different that the practice)

Thanks for all

:anyone:

You don't calculate these things. If you find a lens just try it out. If it works then keep it or buy one if it don't work or gives a weird artifacts in the output.

Ah okay, I must adjust the distance between the diode and the lens...
What do you mean by "if it don't work ?", if I take a lens from a cheaper chinese laser, it will work, isn't it ?

Sorry I don't understand (too) "weird artifacts"

Instead of buying one cheaper laser, where can I find a lens for laser ?

Thanks a lot for your reply

A cheap lens off a random laser may give you splashes and lines around the resulting beam/dot so it could mean that it wont look clean that's what Blord means. You can get 635-660nm(red) laser lenses from DTR and from Aixiz. I am not 100% sure but I believe its possible for a 200mW diode to melt an acrylic lens so you may be best off grabbing a glass lens.

EDIT: Just keep in mind that no matter what lens you get if your diode is multimode(i don't know which diode you are using) you will have to be content with a resulting dot looking more like a small line rather than a round dot. The exception to this is if you get some correction optics and create a housing for it but that will be larger than just a lens and expensive.

Thanks for your reply,

My diode is the same as this link :
658nm 200mW High Power Laser Diode TO 18 Package [JG27]
So it's a simple diode

What the difference between acrylic and glass lens ? the price ? Is acrylic made for high powered diode ?
Can you explain to me how a lens is made for a range of light rays ?

So you think the best is to buy a glass lens for red laser ?
What the difference between this 2 lens ?
-635nm-660nm AR Coated Three Element Glass Lens from DTR
-http://www.aixiz.com/store/product_info.php/cPath/46/products_id/154/osCsid/725fb348221c20215b78828ff05ed13f

Thanks (again) for all your help

Up please =)

The main differences between acrylic lenses and glass lenses are just the lens material. Glass lenses are capable of handling much much higher outputs and is just overall better than acrylic and glass is a little more expensive but its nominal. I would suggest glass lenses for all laser due to them being more robust and just all around superior (IMO)

Each lens is coated with material that prevents reflection (AR - Anti-Reflection) and improves the amount of light that passes through the lens. The coating is fine tuned for a specific wavelength(aka color) of light and works best with the light it is specified for but will work with all (exceptions are in the non-visible spectrum) wavelengths of light at reduced efficiencies.

The only difference between the two lenses is the source. DTR is a prominent member of this forum and Aixiz is a large manufacturer and distributor or laser products. Personally, I go with LPF members before any outside company because I like the community here.

Someone correct me if I'm wrong on something here

Thanks, thanks and thanks a lot, I learn a lot with all your explications...

I think I will choose the lens from aixiz because they sell 9mm Cross Hair Lens for 12mm Casing and if I buy this it will be more easy for me to fit the lens in my custom casing...
But I have a few questions on it maybe you can answer (I hope ;p ) even if no matter I will ask to them...
-What do I get exactly ? only the casing ? (want to be sure)
-On the picture I can see that I must buy a lens + a lens holder, so I must remove the lens (that I want to buy) from it socket and put it on a lens holder ? or can I screw the lens (that I want to buy) directly to this casing ?
-What does the angle Line Generator correspond to ?

Thanks for you reply

The cross hair lens from Aixiz has to be used paired with a standard lens like I linked you to above. Both lenses I linked you too are identical and will work with one of Aixiz's shape lenses.

To use a shaped lens like the cross hair lens you need one of these focus lenses(as sold by DTR and Aixiz):

Then you place the tiny shape lens here:

inside the ring it comes with and screw it onto the main lens so it looks like this:

Make sure you attach the ring with the shape lens inside onto the focus lens on the end that looks exactly like the one that's facing the camera in the first picture.

So for the setup you want you need a lens(make sure its for 635-670nm or within that range and glass) and the shape lens. That's it.

I will assume you already possess a diode module(piece that the diode is stuck in), host(outside shell that you hold), and heatsink for the laser, as well as the diode and driver you have.

BTW, as you can see the lenses are all made to be able to screw in and out of the diode module so focusing them on the fly is no problem.

Thanks a lot for your reply,

Yes of course I have a home made module but no heatsink for it because it can delive 1.5A without it and I just take (max) 0.25A.

I don't understand something you said that I have to put the lens in the metal rings however can we remove the lens from its socket ?(difficult to explain; you know lens you sended me are selled with a piece of metal screwed we can see it on the first picure of your last post...)

What does the angle Line Generator correspond to ?

On the cross hair lens casing where do I put my diode ?
Is this casing can be a heatsink for the led ?

So the cross hair lens casing is not sell with a the lens holder ?

Sorry to post many questions...
Have a nice day

For the heatsink I mean the heatsink for the diode not the driver.

The metal ring is the small piece that screws on to one side of the lens to be able to twist it once its installed. It has a duel purpose in this application because it also is used to hold the shape lens in front of the focus lens. You do not alter the focus lens at all. You simply put the three parts together in the order of:
mounting ring(aka a focus ring)>shape lens>focus lens
With the shape lens being held in front of the focus lens by the metal ring so that the shape lens actually sits in the little groves of the ring and is held in place outside the focus lens. The three parts become a unit and it all move together.

For your diode you are going to need to press it into a diode module such as one of these:

This piece is screwed into the focus lens/shape lens/focus ring unit in this order minus the last piece to the left which is used in certain situations to house the driver but is useless in most applications of higher power lasers:

On top of the diode module you will need a heatsink that is designed for your host that will hold the whole diode/lens unit in the center and pull heat away from it during use. This is an example of a heatsink designed for a C6 host which is a wildly popular host to use:

This is a C6 host and heatsink as seen on clif's website Cajunlasers:

Thanks for your reply with all pics

I understand a lot of things however I don't understand (again) how can I take the lens which is in a piece of metal...
Ah maybe there is finally 2 lens ? one shape lens and a focus lens
Is the shape lens obligatory ? is it possible to have one with just a dot ?

What does the angle Line Generator correspond to ?

So if I buy a Aixiz module what do I get ? Can you tell me numbers ?


Thanks for all

Up please.

I priomise that was my last questions ;p

1: Focus Ring
2: Focus Lens
3: Internal Lens Spring
4: Diode Module
5: unneeded for the most part

The shape lens will fit between 1 and 2. All shape lenses including a line generator (which is just another shape lens that makes a big long line out of the dot) are optional in every way. Without a shape lens you get a dot or as close to a dot as your diode and lens will allow.

Your diode will need to be pressed into #4 with a special tool and you will need a 5.6mm version. I just made a small tutorial for just such a thing HERE.

Hi,

Thanks for your reply

I'm not sure you read me correctly; I want to know what I get if I buy a Aixiz module not what number correspond to.

OK thank for your tutorial, I have a pressed so it will easy (I hope).

OK for the line generator I understand so this aixy module doesn't have a line generator ?
AixiZ 9mm Cross Hair Lens for 12mm Casing, AixiZ
And I will get ONLY a dot ?

Thanks for reading me.