Group buy for 16X dvd burner diodes !

[yuip]

I have just spent an hour reading through the whole thread, at some point I placed an order  ....I am pretty new to laserism and would like to pick some brains here.

I am engineering a tri colour projector using a 10 mw green and, as of this thread, a higher powered red, I am not looking to burn (unless one of the ones I have ordered ends up as a spare  )

My projector has to be portable and my power source will be a 12v car battery (to run the motors/servos/etc.  I have purchased from ebay a couple of 12v to 1.5/3.0/4.5/6 @1500ma regulated supplies) I realise I will need to do a bit of curcuitary but it does not need to be small enough to fit a poiner.

I am a mechanical engineer not too well versed in electronics, though I can follow a circuit diagram and design and solder a vero board. When some of you whizz kids have done some experiments would you please pass on your findings to lesser mortals like me?

An aside, I have probably spent more on parts than it would have cost to buy a laser show on ebay...but where would the fun be in that .

Regards to you all Rog8811

Hey Rog8811,

These diodes should be perfect for mixing with 10mW of green. From what I've read, 650nm red is about 4 times less visible than red, and 660nm (what these diodes lase at) is slightly less visible than 650nm. I think that you would be golden with about 50-60mW of red to 10mW green, so you wouldn't have to overdrive these diodes at all. Then again, I've heard of people mixing 5mW of green with 100mW of red, so I guess it depends on how green/yellow or orange/red you want the color to be.

I can't help you with any electronics knowledge, sorry, but Daedal's guide should be pretty good.

 

[00304]

[quote author=00304 link=1183788027/225#233 date=1185635548]yes i have been but i still have no idea what im looking for i never made one before so i was hoping someone could post a like from radioshacks website of the stuff they are using

I was concerned you might not know how to solder, since you said you would be using liquid solder. If you don't know how to solder it is very easy to learn. You can practice on some printed circuit boards and wires you are not using. Liquid solder is a big no no as far as I am concerned.

A guide on how to solder follows for anyone whom may not know:

http://www.kpsec.freeuk.com/solder.htm

Radio Shack has a variety of soldering irons. I personally use a Radio Shack 25 watt soldering iron.
I also bought a soldering iron stand from Radio Shack, because it makes it so much easier when having to set the iron aside and not worry about burning anything. Part numbers follow.

Catalog #: 64-2070
Catalog #: 64-2078

Any 60/40 formula rosin core solder will work well and Radio Shack has tons of it.[/quote]

thanks ill take a look at those

 

[SenKat]

Okay, all - all the current stock have sold out now - shipping continues next week, and I will post another thread in a few days to start taking advance orders for the next batch if anyone is still interested Thanks again for everyone's patience and support - these diodes KICK A$$ !!!!!

 

[Gazoo]

Okay, all - all the current stock have sold out now - shipping continues next week, and I will post another thread in a few days to start taking advance orders for the next batch if anyone is still interested Thanks again for everyone's patience and support - these diodes KICK A$$ !!!!!

According to the specs I am sure they will kick A$$...lol. I really am looking forward to them. I will probably want to get some more so I will be in for the next GB. Thanks

 

[SenKat]

RAGNAROK - Your 10 diodes are awaiting your M.O., so you are good, man - just didn't want you to think I sold them out from under you, man !

 

[flogged]

Okay, all - all the current stock have sold out now - shipping continues next week, and I will post another thread in a few days to start taking advance orders for the next batch if anyone is still interested Thanks again for everyone's patience and support - these diodes KICK A$$ !!!!!

Dang sold out already?! Fark I knew I should have reserved more than the two I ordered. I was hoping there'd be more excess stock to scavenge.. oh well. I'm definitely down on the next group buy. This is the way to get a diode, ripping apart of DVD drive is a waste.

For those of you that have never built a pointer from 'scratch' be warned that it's addictive. You quickly learn the diode is just a small part of the total package - you need to sort the power supply, housing and optics in addition.

Anyone know what is a safe upper limit on the max current?? The spec sheet says it's ~130mA to get 80mW output. If so I imagine it should be safe to push it to around 200mA which would put the power well into the 100+ mW range. Thing is without a proper laser power meter it's impossible to know the relationship between current to the diode and output power. And it varies between diode to diode, sometime by a factor of two or more.

SenKat I don't know what sort of power supplies you've got, but if you we're to measure the mW output of the diode(s) at 130mA and 200mA (for example, include this info with the diodes) that would be a huge help to those of us without laser power meters. That way we could estimate the slope of the power output and guesstimate a safe upper limit for the current - multimeters are a lot cheaper than laser power meters. I'd be willing to pay extra for this too.

 

[SenKat]

I JUST received a digital power supply (THANKS, COMIDT !!!) So After I get the remaining diodes shipped out today, I will sacrifice a few of mine to see the upper limits - no promises of stability, etc - but by the time they reach everyone, I should be able to have all the info everyone needs - since I may not get around to testing today...dr's appt, and massive hsipping requires most of my attention today !!

 

[yuip]

Thanks a lot, Greg. Better your diodes than mine. J/K ;D

In all seriousness, I plan on feeding mine up to about 700-750mA. Of course they will be cooled down by an ice cold TEC.

If these diodes do 80mW at about 130mA, then I expect about 390mW at 700mA from these babies. That would be including about 10% loss from the glass collimating lens, which I doubt will be that bad. Then again, I'll be happy if I can push it past 300mW.

Oh, and good luck with the doctor's appointment, man.

 

[Comidt]

Cool!!!
Can't wait!

 

[vathink]

Thanks a lot, Greg. Better your diodes than mine. J/K ;D

In all seriousness, I plan on feeding mine up to about 700-750mA. Of course they will be cooled down by an ice cold TEC.

If these diodes do 80mW at about 130mA, then I expect about 390mW at 700mA from these babies. That would be including about 10% loss from the glass collimating lens, which I doubt will be that bad. Then again, I'll be happy if I can push it past 300mW.

Oh, and good luck with the doctor's appointment, man.

Hi yuip,

I suggest that you don't push the LDs past 600mA even with the help of TEC for long term operation. You can push up to 700mA but just be prepared when your LDs only have like 100 or 10 hours lifetime. Based on my personal experience the 18x DVD burner open can red LDs normally died at around 800mA to 1000mA (Yes, I've tried up to 1000mA for a brief period just for personal amusement ;D and I have killed one at 800mA despite the LD cavity was at 12C :-[). Sometimes they died sometimes they don't :. Things aren't created equally in this world. So, if they have a failure threshold at 800mA, pumping 700mA for normal operation is not recommended. I would say 600mA is the sweet spot for power vs lifetime. But then keep in mind, all of these findings only apply to 18x DVD burner open can red LDs. Most likely it will be a different case with this LDs, since it's a different model. Anyway, in the end it's up to every single individual preference on how they would like their LDs to perform. Very powerful but doesn't last very long, powerful and last for quite a while, or not so powerful but last basically forever. Your choice .

PS: The correct working temperature for LDs is usually between 20C ~ 30C. At 24C is when LDs would unleash their maximum power at maximum efficiency, especially in DPSS unit. At <20C or >30C they wouldn't work as efficient. So remember, cooler doesn't always means better .

 

[pseudonomen137]

Thanks for the info about the thresholds! One thing though, in the case of these diodes cooler is better from what I understand. DPSS is not the same because you shift the diodes center wavelength outside of the efficient pump band for the crystals. However with a bare diode, you dont have that problem. You just dont want to get it so that ice condenses on them from the atmosphere, but otherwise cooler will be better. (that's why diodes cooled near absolute zero are quoted in high efficiency experiments)

 

[Gazoo]

You just dont want to get it so that ice condenses on them from the atmosphere

Is there anyway of preventing this? The diode would have to be cooled before it is turned on. I guess I am wondering how long can it be cooled before it starts to condensate, given normal room temperature and humidity.

 

[yuip]

[quote author=yuip link=1183788027/240#247 date=1185807827]Thanks a lot, Greg. Better your diodes than mine. J/K  ;D

In all seriousness, I plan on feeding mine up to about 700-750mA. Of course they will be cooled down by an ice cold TEC.

If these diodes do 80mW at about 130mA, then I expect about 390mW at 700mA from these babies. That would be including about 10% loss from the glass collimating lens, which I doubt will be that bad. Then again, I'll be happy if I can push it past 300mW.

Oh, and good luck with the doctor's appointment, man.

Hi yuip,

I suggest that you don't push the LDs past 600mA even with the help of TEC for long term operation. You can push up to 700mA but just be prepared when your LDs only have like 100 or 10 hours lifetime. Based on my personal experience the 18x DVD burner open can red LDs normally died at around 800mA to 1000mA (Yes, I've tried up to 1000mA for a brief period just for personal amusement  ;D and I have killed one at 800mA despite the LD cavity was at 12C  :-[). Sometimes they died sometimes they don't  :. Things aren't created equally in this world. So, if they have a failure threshold at 800mA, pumping 700mA for normal operation is not recommended. I would say 600mA is the sweet spot for power vs lifetime. But then keep in mind, all of these findings only apply to 18x DVD burner open can red LDs. Most likely it will be a different case with this LDs, since it's a different model. Anyway, in the end it's up to every single individual preference on how they would like their LDs to perform. Very powerful but doesn't last very long, powerful and last for quite a while, or not so powerful but last basically forever. Your choice  .

PS: The correct working temperature for LDs is usually between 20C ~ 30C. At 24C is when LDs would unleash their maximum power at maximum efficiency, especially in DPSS unit. At <20C or >30C they wouldn't work as efficient. So remember, cooler doesn't always means better  .[/quote]

Hey vathink,

Thanks for the info! I love your work with pushing these little diodes to their limits. I will be using Daedal's driver and modify the resistor(s) to drive it no more than 600mA. Thanks man!

 

[Aseras]

[quote author=pseudonomen137 link=1183788027/240#250 date=1185817208] You just dont want to get it so that ice condenses on them from the atmosphere

Is there anyway of preventing this? The diode would have to be cooled before it is turned on. I guess I am wondering how long can it be cooled before it starts to condensate, given normal room temperature and humidity.
[/quote]


you pot the connections and on the high end stuff, you seal everything up tight and put it under a inert gas so there's no water in the air inside. All of my stuff gets bottled in argon when it goes deep. It's often close to freezing, so florida air + freezing in seawater = condesationa all over inside. can't have that.

 

[vathink]

Thanks for the info about the thresholds! One thing though, in the case of these diodes cooler is better from what I understand. DPSS is not the same because you shift the diodes center wavelength outside of the efficient pump band for the crystals. However with a bare diode, you dont have that problem. You just dont want to get it so that ice condenses on them from the atmosphere, but otherwise cooler will be better. (that's why diodes cooled near absolute zero are quoted in high efficiency experiments)

You are right actually on this one. I had my mind on DPSS laser at the moment so that was the first thing came across to my mind when I wrote my post (I'm still playing around with my DPSS laser at the moment ;D). I stand corrected.

yuip: Before you do anything with your LDs when you have received it from SenKat, hear what SenKat got to say about the safe limit / failure threshold of this particular LDs. I heard he's going to try to find out the magic number for us. It might not be able to sustain 600mA at all. Who knows, but time will tell ;D.

Thanks .

 

[yuip]

Yeah, that could very well be the case. It makes sense though that these could very easily do 250mW CW under enough cooling, considering that's what they are speced at pulsed in the data sheet. If I could get that much out of one of 'em, I'll be pretty happy. I don't really expect to match your 400mW, but want to come as close as I can.