Blu-Ray laser diode hack

[aaron_inc]

i have made a blueray pointer but my camera always makes it look brighter than it really is so i took a photo of the laser when it was turned off and edited it to show how bright the dot seems to my eyes in a moderately lit room.
does everyone elses look like that or do i need to turn up the current.

 

[Guliver]

Hi Aaron, No ours look much brighter

Hey guys
Thought I'd let you know of some of my results with these diodes..

My two, purchased from the same seller on ebay netted two
combination Violet/Red/IR diodes.
Both started threshold at about 22 and 27ma both output 22mW at 42ma..
I didnt push them much higher .. I figured these as low powered units and
from Spec and I's previous experience with the low powered units. so,
I didnt go any further as they will NOT live long at this level.
Altho, They would be very comfortable at around 7 to 12mW CW out.
Remember these are pulsed diodes and we are them using CW.
As Pulse wouldnt be brighter anyhow.

So anyhow, Back in November when Spec came down to my place to put
together the first pointer and module, we had pretty much the same result
except with those diodes threshold was a bit higher (about 32ma)
which netted about 25 to 35mW easily from those diodes (they were from burners).
We didnt push these as things were getting expensive and our previous failure
of getting the reader diodes to work without destruction made us weary.
So we stopped there knowing at least we had something worthwhile.

During our experiments we thought we had gotten a bad diode and scrapped
it (placed in the junk diode bin for later use) and another diode
that went bye-bye during our tests was also placed in that bin.
Well, after reading Robins post on alt.laser descibing his results with a diode that was presumably bad
and seemingly coming back to life at a much higher threshold.
So, I decided to pull out one of those diodes that was thought bad.
And after mounting, I ramped the current up past the old threshold of around 33ma
to about 45 and noticed that the diode was getting just a bit brighter , than
after hitting about 70ma it started to lase again..wow, unbelievable.
It was actually working again so I chatted with Spec to tell him the result
afterall it was his diode..so anyway he asked me to ramp it up higher without fear of COD
so I did..at about 115 ma I got 16mw out..
so to continue in the sake of science I ramped it up to 180ma and got a return of 30mW..
while watching the current meter approaching 200ma the diode went out like a light..
I didnt get to see at what mW it died at but still..It was a surprise to say the least..
the diode actually lived again after we had thought for sure it was dead..

So there you go,.If by chance you think your diode is kaput,.
unlike other types of diodes which just draw more current and got hot.
Try it again.

 

[aaron_inc]

Hi Aaron, No ours look much brighter

well it looks like id better crank up the current:rock: it could also be my eyes, is it normal to be able to see the light from a remote controll if its really dark and you have it right in front of your eyes? if not then my peak sensitivity might be a bit further towards red.

 

[liveforphysics]

Aaron- If you read my previous post, the case in your picture is the same case that has a lens which is not suited for passing light of this wavelegnth due to fluorescence.

Aside from that, I think it is the worst case available as a diode host of any wavelegnth for a variety of other reasons, but people still seem to use them most frequently...

The little brass ones with glass optics are cheaper, and focus much nicer, and use a lens with a focal legnth close enough to actually capture all of the wide beam emmited from many diodes.

Best Wishes

 

[SenKat]

Live for physics - Where do you get the brass housings with the glass optics ? Do they come from Aixiz - Meredith ? I requested Glass optics when I purchased all those housings - and received plastic, I guess....(I bought from Aixiz)

 

[liveforphysics]

Senkat- I've got some pics of them in my original Elaser thread. I don't remember what seller I bought them from, but it was somebody on ebay. I belive they were something like $3.50 per unit. The diode is easier to poke out than the Axiz chrome cases as well, and you can actually move diodes from case to case if you are careful.

Definately glass, definately very fine threaded brass focus adjustment, definately a lens with a focal legnth close enough to get all the beam into it rather than wasting it on the sides of the black plastic lens holder on those garbage chrome Axiz modules (which I still have around 10 of laying around that I will never use for anything again).

 

[Conceptcar3]

I am looking for the same thing- glass lense adjustable focus diode modules for cheap. What is the best one? http://thelaserguy.stores.yahoo.net/635nmredladi.html
I ordered that... was that a waste of money or is that one viable?

 

[liveforphysics]

That looks exactly like my favorite little brass modules. I have no idea if it uses the same glass lens, but the appearence of the case is spot-on.

Best Wishes

 

[aaron_inc]

Aaron- If you read my previous post, the case in your picture is the same case that has a lens which is not suited for passing light of this wavelegnth due to fluorescence.

i dont think it is the lens, i have run the diode outside the housing and i see no real difference in brightness. i'm using the Axiz housing with the glass lens.
i have tried running it from 30ma to 80ma and the output is pretty much the same.

 

[Conceptcar3]

how are you driving it? are you giving it at least 5 volts?

 

[dr_lava]

Remember these are pulsed diodes and we are them using CW.
As Pulse wouldnt be brighter anyhow.

Aren't read lasers CW? 10-12mW seems right with all the optics in the path, but what would be the purpose of pulsing a read laser?

 

[aaron_inc]

i found the problem!!!! it was the variable resistor i was using! i got rid of the 100 ohm resistor because it was set at 0 ohms and now it is running at 6v and 100 ma!!!the resistor was causing a 2-3v drop so the laser was only getting 3-4v.
i blew one of my diodes though i was making a quick little board for it and i accidentally shorted the laser straight to the battery there was a bright flash of violet light then it was dead. it dosent even give a dim glow. that was the weaker diode though, i have the stronger one running now and in sure its one of the write diodes, theres no way 10-15mw of 405nm light is this bright it has to be 30-40mw i can see the beam if it is dark .

 

[ajohnson]

How long did it take you guys to get your ps3 units / diodes? I ordered mine not long after the initial post and still dont have it

 

[aaron_inc]

i did the express post so i got it in 3 working days but with the normal post it takes a long time, nearly all of his feedback said it took ages in the mail so it might take a while.

 

[ScarabDrowner]

I just got my ps3 sled in today, and upon disassembly it occurred to me, is it not possible to use the electronics that are intended to power the laser in a different host? I see people trying to figure out circuits and such to power the diode, but why not use the one that came with it?

 

[liveforphysics]

I belive it is because the factory circut has no need to run the laser harder than a few mW. Running it harder could actually damage the disks. Remember, its a player on not a burner, it just appears that the diode they used has nice overhead for harder driving.

 

[ScarabDrowner]

good point... ah, it's moot anyway, since my diode broke off of the circuit while I was trying to remove the heatsink. I have an interesting idea for a way to use the diode to it's full potential, but I need to draw up a schematic first.

 

[SenKat]

Draw...then share ?

 

[ScarabDrowner]

Ok, here's my idea.

The laser diode from the PS3 sled apparently can produce both red and violet light, depending on how it's wired up. Unfortunately, each wavelength seems to need a different focus, i.e. with the lens focused for violet collimation, it won't work for red, and vice versa.

My idea is to use two different lenses, one focused properly for violet, the other for red, and to be able to switch between the two as desired:

With the switch in the red position, the red lens is moved in front of the diode, and the circuit powering the red laser is completed. Same with the violet side. Off position would be in the middle, which could also be used to provide a kind of dust cover for the aperture. Also, if different boost circuits are needed for each wavelength, this would still work with that as well.

Granted, it might not work in a cylindrical body, but it might be worth a try to get two lasers out of one ^_^.

 

[SenKat]

Now, THAT is a unique Idea ! I think the red part of the diode is relatively low powered - 5-10mw if I am not mistaken ? It should still be a challenging and rewarding project, though !