Need information about lens

G1 and G2 lenses are nearly identical its just G2 lenses tend to be a little easier to get and very slightly cheaper. G1 lenses are nearly unnoticeably better than G2s. Both G lenses are far superior output to 3-Element lenses but the beams they produce have less divergence so the beam spreads quicker making the dot larger at the same distance. G lenses are superior burners by a long shot unless you want to burn at long distance.

M140s tend to range from 4.5-5.5V depending on the current you give them. M140s burn very well because of their super high output. Your LM317 has a max current of 1.5A right? M140s typically run at 1.2-1.8A with 1.8A pushing the diode pretty hard. 1.4A would preserve the diode and give you a much better run life while still allowing outputs of maybe 1.2-1.5W depending on diode efficiency. If you had it run at that current behind a G lens you would have an amazing burner that can light cigarettes NP.

For thermal performance You would need to run the M140 in a copper module and I would suggest using a copper heatsink as well. Don't forget to heatsink your driver at that current because linears like to make some heat

Thanks a lot for your help

You are right for the LM317 and of course with a heathsink ^^

Is the aixiz's module suffisant to use as an heathsink ?

So if understand we use for long distance glass lens and for short distance Gx lens.
What is for you a short distance and a long distance ?

Maybe do you have a M140 diode ? Do you think I have a chance in the sell section ?

What is the nominal current for this diode ? because you are not really sure, it's approximaticly...

thanks for all

No, the aixiz module isn't near sufficient for a heatsink. You will need to mount the module inside a rather large chunk of aluminum or copper for sufficient heatsinking. Here are a few threads for people selling heatsinks designed for specific hosts, the third one is DTR's page that has additional links:
http://laserpointerforums.com/f64/fs-custom-machned-aluminum-heatsinks-45973.html#post618627
http://laserpointerforums.com/f64/eudaimoniums-machine-shop-73749.html#post1064691
https://sites.google.com/site/dtrshostheatsinkkitpage/

You are correct about the lenses. 3-element lenses are good for pointing to infinity while a G lens will make a dot that's about 2x larger than a 3-element at about 50 or so feet.

Here is the best place in my opinion to get an M140 diode:
https://sites.google.com/site/dtrlpf/home/diodes/445-m140-didoes

The current you would want to run an M140 really depends on your heatsinking and how long you want your diode to live. I run most of my M140 diodes at 1.8A because I am very careful not to run them too long so that they overheat(called duty cycle) and I like having the power I get from that high current. A very stable yet still powerful current range is 1.2-1.4A and it is the current range I would suggest for maximum efficiency and diode life. The closer you push to 1.8A the hotter it gets and the shorter your diode's life will be.

You could use this graph to compare the output of the different lenses.

http://laserpointerforums.com/f52/lens-comparison-445nm-h1600-diode-75324.html

I don't know the beam specs right off a H1600 diode or how they compare to a M140. Assuming M140s are the same or close then that graph should be fine.

If the beam shape is any different it could effect each lens differently due to varying distances that the lenses sit from the diode and how much of the light bar hits the lens or not.

The H1600 and the M140 diodes are the same. The names are from the projectors from which the diodes come from.

Interesting they used the same diode.

Something to note about burn power of G lenses vs 3-Element lenses is while the G lens allows more light it only has better burn power while at a closer range due to the fact that it has inferior divergence and makes a larger dot at more than a few feet. I use G lenses for burning close things and 3-Element lenses for burning at further distances.

Thanks that's help me a lot.

WTF ? we can see on the graphe that an aixiz acrylic lens is as performed as a glass lens ?
But we can't use it for high power, is that correct ?
WTF(2)?we can see on the grphic that the wavelenght for glass lenses have no impact on the ouput, and a 650nm is more powerful than a 450nm, can you explain that ?

OK so I must make or buy an heathsink for the diode too...
Have you got the coefficient of temperature dissipation I mean something like
heat energy=Power*deltaTime*dissipation of the diode
yeah I like math =)
or maybe do you have a datasheet that will be fine

Thanks

Acrylic is a plastic but it isn't much inferior than a glass. We use glass lens because the barrel is made from metal and it won't melt under high power of the 445nm diode. The acrylic lens will do fine but the black plastic barrel will melt.

The total surfaces has much bigger impact on the performance. Each time light pass the surface a part will be reflected. The standard Aixiz lens has two surfaces, front and back of the lens. The 3-element glass lens has already 6 surfaces. That makes a big impact on the output.

The 650nm lens is also a single element lens. It gives the lens the advantage despite the "wrong" ar coating.

Exactly what Blord said.

I vaguely remember someone actually having an acrylic lens itself fail when being pushed by a 2W 445nm though. I think it had something to do with the AR coating not handling it.

If you want to compare the "650nm AR 1-element glass" to a "405/445nm AR 3-element" lens it is an unfair comparison. The comparison should be between another single element glass lens such as the "405/445 G-1" which would be a landslide win. About the Acrylic lenses, it would suck big time if your lens barrel melted in the middle of using your laser. The "standard Aixiz acrylic" lens may have an advantage over the 3 element lens in raw output simply because it is only a single lens but again you cant compare a single element to a multi-element. A G lens would be yet another landslide win in you wanted a single element. Another thing is with 3-element lenses, while they have decreased outputs, they have superior divergence and are often worth the loss in favor of improving your dot size at a distance. IMO the graphs should have had the single elements grouped together and the multi-elements grouped.

It goes down to this
Single Element Winner: 405/445 G-1/2
Multi-Element Winner: 405/445nm AR 3-Element

About heatsinks, I do not have any numbers but with diodes a good rule is the smaller the heatsink the less you can push your diode unless you don't mind having a low duty cycle. Also, copper is superior to aluminum for heatsinks in a pointer in every aspect thermally.

The question now is, what are you planning on putting your laser in?

Thanks (again) for your answers I understand better now...

And for finish with lenses is there a big if we use a different wavelenght lens compared to a lens with the adequate wavelenght for a diode(with of course the same number of element) ?

I see somewhere that the M140 diode are sell for some seller with an output of 1W and other for 2W however in reality they have an output of 1W so I must use approximaticly a current of 1A, am I wrong ?


Thanks for all

The finish on a lens is called an AR(anti-reflective) coating. Its intended to aid in the light passing through the lens and not getting reflected back off it. If you use a lens with the wrong coating you will have great loss due to more of the light being reflected back. In some cases the reflection can be so great you may even reduce the diode's life because of the feedback, or so I have heard. You are best off using an AR coating designed for your diode's wavelength.

M140 diodes are all capable of being driven to 2W or near 2W. Anyone selling two grades has likely tested them out individually and separated them out based on the individual efficiency. Some diodes are more capable of going higher than others. Diodes with less efficiency are usually candidates for being less driven and just keeping them down at 1W. for 1W you will usually need a current of about 1.2A but there are some super rare diodes capable of as much as 1W at .7A. If you want a 1W drive the diode at 1.2A, if you want a 2W drive it at 1.8A. While I cant guarantee you will hit 2W at 1.8A you will almost always get very close and sometimes pass it to as much as 2.5W.

TIP: Avoid ebay for diodes at all costs as you may even be sent an A140 and those are inferior. You are best off with DTR for a random(possibility of an extreme efficient or standard) M140 or Flaminpyro for a handpicked(more expensive) high efficiency M140.

Overall 1.2A is much safer for long life and less heat but 1.8A will give much more power and a better burn. Its personal choice.

Again, what host are you planning because that will limit your capabilities?

Thanks a lot for your reply,

I understand now how is it important to have the correct wavelenght lens for a diode.

I wasn't thinking that there is huge difference between these diode (simple to double...).
So what is its nominal output ? 1W ?

I think I will make my custom hostmade with copper for base I will use the aixiz module.
The heathsink for the diode will be a piece of copper which surrounding the module. Do you think it will be suffisant ?

Thanks

By aixiz module I hope you don't mean the one from aixiz.com because those are inferior material. You are much better off getting a copper one from DTR because so far his are hands down the best I have used.

I guess the nominal output for a M140 would be 1W but even that is over driving the diode above spec. Maximum spec current for an M140 is 700mA but every(nearly) one can handle up to 1.8A and some even more than that. If you want to do a homemade host/heatsink I suggest you keep the current down to 1.2A.

I cannot say if it would be sufficient because just knowing the material doesn't tell me how much of it you will be using. The more the better. In my mind a "a piece of copper which surrounding the module" denotes a very small amount of material and would be FAR too little to cool it. A good heatsink would consist of around 1oz of copper or more IMO. You also need to make sure than you have extremely solid contact with the module or you will not get good enough heat transfer and will burn out the diode very quickly.

Here are a couple reliable websites to get ready-to-go hosts from that include heatsinks made for aixiz modules and the second link has links to more sites:
Host Assemblies
https://sites.google.com/site/dtrshostheatsinkkitpage/

Or you could always grab a heatsink and modify it as needed to put in a host or make a host around the heatsink:
Heat Sinks
http://laserpointerforums.com/f64/eudaimoniums-machine-shop-73749.html

Thanks for your reply

Yeah I know I didn't tell you more detail about the heathsink....

But I don't know what to do because yobresal is selling a great deal. You tell me that you have one of his kit are you satisfied with it ? does the heathsink for the diode suffisant ? isn't in copper right ? is it really a M140 ? or a A140 ? Is there an heathsink for the driver ? what is the materiel of the host ? aluminium or plastick ?
(this question is stupid but does it burns things ? like cigarettes ?)

Thanks

Yobresal is selling a completed laser and a kit. His lasers are true M140s and the heatsinks used are sufficient. His base model laser might be using an aluminum heatsink but I am not sure. He heatsinks the drivers he has that run at higher power other than the 1.2A version since the drivers don't need it at that current. The Blue Ice host is an aluminum host and it is one of the only materials other than maybe steel and silver(lol) that I would suggest to use as a host. His lasers burn just like any other M140 at that output would so, yes they burn well. If you are planning on buying a kit please note that they are not designed for a diode module and you have to press the diode directly into the heatsink. Its more difficult to do but it is thermally superior. His complete lasers are ready to go and work great and I have one of the premium 2W lasers.