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blu-ray at 118mA working but not burning! why?

alx

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Today, i've finised my first blue laser. I know that at 100mW violet laser can burn white paper, deal with skin, etc Even unfocused, a PHR can be felt. My problem is that at 118mA, i can not lit anything. I can feel on my hand from 1m away, but... i cannot burn anything!!! I think is a focus/colimating lens problem. With my red laser, i was able to lit matches ONLY when I replaced the original plastic lens with AIXIZ glass lens. On blu laser, i tried:
- aixiz plastic (just shining nice)
- aixiz glass (seems to be better collimated, blue dot is smaller, but i cannot lit)
- dx plastic lens (like aixiz plastic)
Now, my blue laser is running with dx plastic lens which comes with original housing module. I cannot burn white paper even if is closer (less then 20cm) and cannot lit matches.

Can somebody tell me what was the distance you tried and worked to lit matches/burn white paper using phr-803t diodes? What lens are you used? As i read/know, for red lasers, glass lens are recommended but for blue, only plastic lens are good to be used. In my case, no one is working. What lens are you susing?

regards,
Alx
 



daguin

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Do you have laser goggles designed for the 405nm range?  It sounds like you are not really getting it focused.  A focused violet laser is a VERY tiny dot.  You may not be able to see the actual dot because of the "blaze" surrounding the dot.

Also, what are you powering your laser with?  If you are using a 9V battery, the battery may be sagging so quickly that you are not putting out anywhere close to 118mW

Finally, how do you "know" that you are putting out 118mW?

Peace,
dave
 

Ieon

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daguin said:
Do you have [highlight]laser goggles designed for the 405nm range[/highlight]?  It sounds like you are not really getting it focused.  A focused violet laser is a VERY tiny dot.  You may not be able to see the actual dot because of the "blaze" surrounding the dot.

Also, what are you powering your laser with?  If you are using a 9V battery, the battery may be sagging so quickly that you are not putting out anywhere close to 118mW

[highlight]Finally, how do you "know" that you are putting out 118mW?[/highlight]

Peace,
dave
He proberly doesn't have laser goggles, neither a meter.

So it is proberly a bad diode or his focusing is bad or maybe the diode isn't "flush"?
 

alx

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daguin said:
Do you have laser goggles designed for the 405nm range? It sounds like you are not really getting it focused. A focused violet laser is a VERY tiny dot. You may not be able to see the actual dot because of the "blaze" surrounding the dot.
Indeed, i forgot to mention that i don't have yet a violet goggles and my assumption regarding focus seems to confirm. My goggles are on the way!

I am powering my laser using a big accu 7.4V/1620mA. Using the same accu, my red laser is working like a charm. Is not a power problem!

daguin said:
If you are using a 9V battery, the battery may be sagging so quickly that you are not putting out anywhere close to 118mW

Finally, how do you "know" that you are putting out 118mW?
dave
I said 118mA, not 118mW. The driver has been set to output a 118mA current! I don't know the output power, i don't own a LPM, but as other people said, estimated output power should be around 100mW.

Which lens are u using at your blue laser?

Regards,
Alx
 

alx

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Ieon said:
He proberly doesn't have laser goggles, neither a meter.

So it is proberly a bad diode or his focusing is bad or maybe the diode isn't "flush"?
Yes, no goggles, no LPM. No dout: blue ray diode is good and flushed ok into aixiz (the output dot is showing me a perfect round spot on the wall, no distorsions, no other strange forms).

Did you use plastic aixiz lens (the original one coming with aixiz module) or glass aixiz lens?

If focused, what is the max distance at you can burn matches, or white paper? less then 1m or ...?

regards,
alx
 

Ieon

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alx said:
[quote author=Ieon link=1235864474/0#2 date=1235869258]

He proberly doesn't have laser goggles, neither a meter.

So it is proberly a bad diode or his focusing is bad or maybe the diode isn't "flush"?
Yes, no goggles, no LPM. No dout: blue ray diode is good and flushed ok into aixiz (the output dot is showing me a perfect round spot on the wall, do distorsions, no other strage forms).

Did you use plastic aixiz lens (the original one comming with aixiz module) or glass aixiz lens?

If focused, what is the max distance at you can burn matches, or white paper? less then 1m or ...?

regards,
alx[/quote]
What brand of matches is it anyways?

Some matches are HARD to light some are EASY to light.

If you light a pack of matches in your room you should be able to the beam and focal point so you can hold a match there and if it doesn't light there your diode is stuffed.


I know your powering it with 7.4V its needs more then that, you should try a regular non-rechargable rectagle 9v.
 

rog8811

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With the setup you have described and a known good power source you should have no problem lighting matches almost instantly.
Have you opened out the back of the acrylic lens nut? If not do so, it will make a difference.

Regards rog8811
 

alx

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rog8811 said:
With the setup you have described and a known good power source you should have no problem lighting matches almost instantly.
Have you opened out the back of the acrylic lens nut?  If not do so, it will make a difference.

Regards rog8811
i am identifying 3 directions:
- goggles (will be here in 2 weeks), so i will wait... I saw that without goggles, is difficult to have a focused laser - under less then 20cm away, the spot is very very brighter and I cannot look inside it with my eye.
- i will try with different matches (i used one - no name)
- finally, lens. in my cases, like many others, aixiz plastic lens should work fine.

Regarding your suggestion: no i have not open the back of acrylic lens nut. I would like to try now. Can you post a picture about how it looks its's back before and after? maybe a link or a mini how-to about how to do that?

regards,
alx
 

charliebruce

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The best way is to use a sharp craft knife to slice the very end of the module off totally. Just be careful and roll the module around (carefully) so as not to bend the plastic. It gives a "dirtier" beam but slightly more power output.
 

alx

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That's it! The back of lens has been opend. Also, i used my red goggles to focus the beam at 30cm away! Now, I am able to lit matches in 2-3 seconds.

I can confirm: without goggles is almost impossible to have a properly focused beam (the spot is very very thin and strog indeed - you can't look at it without goggles)

Unfortunatelly, i cannot lit white paper at all. If other peoples can, I am suspecting that i own a less powerfull blu-ray diode (because the driver is set at 118mA which in most cases is enough to obtain 100mW) or the focal distance should be lowered. At what distance shoud i focus my laser, to be able to burn white paper?

Regards,
Alx
 

rog8811

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I am not sure you will be able to light white paper, I can cut paper with my laser lighter with focus set at 45mm which is the edge of the lighter lid.... which keeps the laser in perfect focus. All I need to do is sit the lid on the paper and move the laser around.

Regards rog8811
 

charliebruce

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Red goggles are going to offer very little help if you're using them to reduce the brightness of the spot. you'd be better off using a pair of dark sunglasses... They would help reduce the brightness but offer little protection from direct hits. The ideal focus point is when the spot becomes absolutely tiny on whatever you're trying to burn. The principle is that all the energy of your laser is focussed onto an area the size of a pinhead, thereby resulting in a very high temperature at that specific point. At that power it will certainly not be able to light paper, but if focussed properly (so the dot is pinhead-sized when viewed through proper protective eyewear) it should singe it quite nicely. Receipts burn much more easily than standard paper, do you have one you could test it on?
 

billg519

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It can be the diode. I have two PHR-893T's that when driven with 120mA read 62mW and 67mW respectively on my Lasercheck. Not very impressive, but they did come from reject sleds. My other PHR's do much better, all being well over 80mW when driven at 120mA. For focusing to burn, try focusing the laser at maybe 3 to 6", using black paper. The black paper will reflect less light back at you, so it will be easier to focus without laser goggles. You should be able to get a tiny burning spot easily this way. Then, just hold the laser at the same distance to test burn other colored items like white paper, etc.
 

alx

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charlie bruce said:
Red goggles are going to offer very little help if you're using them to reduce the brightness of the spot. you'd be better off using a pair of dark sunglasses... They would help reduce the brightness but offer little protection from direct hits. The ideal focus point is when the spot becomes absolutely tiny on whatever you're trying to burn. The principle is that all the energy of your laser is focussed onto an area the size of a pinhead, thereby resulting in a very high temperature at that specific point. At that power it will certainly not be able to light paper, but if focussed properly (so the dot is pinhead-sized when viewed through proper protective eyewear) it should singe it quite nicely. Receipts burn much more easily than standard paper, do you have one you could test it on?
Dependig by goggles... I own a pair which is designed to filter better red spectrum (590-650nm) but also can filter ultraviolet 200-400nm. As time as phr wave length (405nm) is near upper ultraviolet filter, it can be used with good performance! On the way is a dedicated goggles for blue and violet spectrum (which will be optimal in this case). I not need to use dark sunglasses. Aha... good point to use a receipt ;-) I will try using one. Anyway, the final test will be when I'll receive violet goggles.

thanks for your hints,
alx
 




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