Diodes Compilation - All Diodes Data In One Thread!

[cappernicus]

Copper has better thermal conduction than aluminum, but aluminum is usually fine. What matters more than the type of metal is how good the connection is to the heat sink(press-fit, soldered, heat sink grease, etc.).

The numbers that you mention will not yield any useful information as far as we have been able to determine. The best thing to do is to examine/test them yourself. Here are a few guidelines:

-9mm can diodes are only CW in powers up to 2 watts.
-Generally, a bigger chip with more or bigger wires can take more power.
-From what we have discovered high power diodes are USUALLY case positive, red and IR both. If both are isolated from the case, the wire attached to the top of the die is negative.
-A great way to test the polarity is use the diode test function that is available on most multimeters.
-When trying to determine rated power the best thing to go off of is the threshold current at which it begins to lase. If you got them from Heruursciences/Hesc_photonics then they are LIKELY from Boston Laser. If you want I can post the specs from them because their site is gone. If they are from other sources I can't help you.
-Turn up the power of a good diode until it dies. Identical diodes should not be run at more than (very) roughly 2/3 of the power at failure.
-IR usually runs at 2.2v, red usually runs at 3v
-The wavelength can sometimes be determined by the color tint of the front facet of the die. For example, if it is half green and half pink(lengthwise) then it is probably an 808nm diode. If it is purple, then it is probably a red diode.

Hope this helps!

 

[canpower]

Thanks for the info cappernicus.

I really DO have a mixed bag of diodes here, the C-mount ones I know are all IR and 1/2 watt, but the ones in the can are somewhat of a mystery to me, one of them even has a tint little "buldge" type window, less than 2mm in diameter, it looks like a little glass bead lense of sorts or something like that, but most of the other ones in the can seem to be either 2 or 3 lead diodes, most of which I've determined to be IR, but I'm just not sure what "wavelength" they really are.

I know I'm NOT supposed to be looking directly at the diodes output, but if I am holding the diode FAR away, and NOT looking directly into it, kinda looking at it from the side, just peeking around the edge just far enough to see if something glows or not when power is applied,I can see it glow with a tiny red element if the polarity is correct, but oddly, a few of them seem to glow "white", and not red at all. What wavelength would "these" diodes be?

I know all my C-Mount diodes are 808nm, but the can ones are a mystery, how can I tell at all?

I often use my camcorder with night vision mode to view the diode when I power it up, as you can see it lasing, and see a beam emitted from the front of the diode quite strongly on the half watt ones. When i apply 800ma to the 1/2 watt C-Mount diodes, and put my finger in front of it, I can definitely feel my fingertip burning quite a bit, so I know it's putting out alot of IR beam. I have a few 532nm green laser pointers that I've removed the "dead" IR diode from, exposing the crystal, which appears green in colour, I kinda expected that pointing the uncollimated 808nm beam into the diode housing where the old diode was removed from (the new can diodes I have are 6.8mm inner diameter & 9mm outer diamerter round, and far too large to fit into the hole where the old diode was removed from) would result in at least a "little" bit of a green output from the collimation lense of the diode assembly, but there was nothing, why is that? I even tried putting a little collimating lense to focus the IR output beam tighter against the green surface of the laser pointer module crystal input, but not even one green photon could be observed, what am I missing here? The pointers "do" operate on 808nm don't they? I've tried quite a few different green laser pointer crystals I have, but no cigar.

What exactly can one do to "collimate" a C-mount laser diode? I know there are specific housings meant for C-mount, but how would one go about interfacing one without purchasing a particular collimating assembly meant and made for a C-mount laser diode?
Thanks again for your reply!

 

[cappernicus]

I am not sure, but I think the diodes that emit a little bit of white are 980nm. I have observed the same effect with some that I have. A better way to do that though would be to point it at a piece of white paper, keeping your face far enough away that the reflected light will not harm your eyes.

I have never seen one, but I am guessing that the 9mm diode with the bulging window is a diode with Fast Axis Correction. They aren't as common and they should collimate like a normal single mode diode.

808nm is very visible, 980nm is barely visible, and 1400nm+ is completely invisible. Other than that I couldn't tell you because I don't have IR diodes with verified wavelengths other than 780, 808, and 1550.

Collimating multimode diodes requires a normal lens and also a cylindrical lens to correct the fast-axis. You can purchase collimating modules that have both these lenses, but how you mount them depends on the collimating unit, and whether or not you are willing to make or purchase mounting parts. Jayrob is an excellent source for custom machined parts.

As to your problem with the green laser crystals, they require high precision to work. Also, they work most efficiently when the IR beam is focused so that the waist of the beam is inside the vanadate crystal(see here for a diagram). Most of the cheaper lasers just put the crystal as close as they can to the diode without touching the chip. You are basically doing the same thing except that your IR pump is not close enough to the crystal. It has to be very close to work at all.

Niko:

The thread I linked to has a lot of useful info. I don't know if you already looked it over or not, but if you haven't it would probably be a good idea.

 

[canpower]

Thanks for all that VERY useful info!

I know I've got alot to learn (or should I say "re-learn"), but it's kinda hard for me to absorb info after a head injury I suffered some time ago, it really sucks! I "used" to be a very serious researcher before that happened, and actually, back in the early 90's before all this technology was so avaliable, i was even experimenting sucessfully with building nitrogen lasers, some of which punched a good 1cm hole in my lab wall one time, so that gives you an indication of my previous involvement with lasers, but as you know, technology changes, and gone are the days where 3 stacks of plate glass home made capacitors, leyden jars, and stacks of coupled microwave tranformers are needed just to ionize some gas in a trench or in a glass tube! Now things are "much" more "gentle" and specific, it's almost a "graceful" art when you think about it, all that alignment and care to create these tiny setups and configurations comprised of tiny crystals and tiny laser diodes mounted in a case, just so a human finger can "actually" manage holding the diode without special tools! It's kinda crazy when you think of it.

Anyhow, I "was" reflecting the diodes light off of a peice of white paper, but noticed that the ones I thought were DEAD, we actually emitting tat tiny white glow at the diode's junction, that went unnoticed when trying to view the reflection off paper, as nothing reflected, it's "white". That's why I started using my camcorder in night vision mode to detect the beam.

Again, some of the light emitted from the diodes appear "white" in the camcorders display, while others appear to be a faint reddish pink, and yet some are not emitting "anything" that I can detect either with the naked eye or the camcorder, yet the diode test on my multimeter still shows the proper biased voltage drop, so I "assume" it's still a functioning diode, just not at a wavelength that can be observed. Oddly enough, there is no smoke visible when I put the roll of black electrical tape up to the output of the diode as there is when i do that with one with a very visible red IR beam, even the ones that glow white do not burn the roll of tape. I wonder why?? Any ideas?

I've tried "collimating" the beam output from one of the diodes that are 808nm, and can be viewed as quite a strong reddish beam through a "tubular" lense assembly that came out of a green laser pointer, (it has a lense on both ends), and then pointing that pinpoint of a beam output from that lens at the input of the green crystal surface from a green laser diode assembly I've removed a dead diode from, but nothing.

Any ideas "why" I don't get even one photon of green light when I even focus the 808nm beam to a pinpoint right on the surface of the green crystal, "exactly" where the old diode that was removed would have pointed it's beam? Like i say, I've tried about 4 different crystals from different green laser diode modules, and even tried a few other laser diodes that are supposed to be 808nm, but nuttin. Hmmmm....

thanks for the info and for reading all of this ranting!

 

[nikokapo]

@cappernicus: Sorry, I can't read it all right now, I have two tests this night. Though I will tell you that I did base the DT on the thread you linked. The big missing part on the DT right now are power graphs.

 

[cappernicus]

That's ok. I wish I could contribute more but I don't know how accurate my meter is. Are you planning on including the secondary diodes from the common sleds? Any IR diodes?

 

[canpower]

Copper has better thermal conduction than aluminum, but aluminum is usually fine. What matters more than the type of metal is how good the connection is to the heat sink(press-fit, soldered, heat sink grease, etc.).

The numbers that you mention will not yield any useful information as far as we have been able to determine. The best thing to do is to examine/test them yourself. Here are a few guidelines:

-9mm can diodes are only CW in powers up to 2 watts.
-Generally, a bigger chip with more or bigger wires can take more power.
-From what we have discovered high power diodes are USUALLY case positive, red and IR both. If both are isolated from the case, the wire attached to the top of the die is negative.
-A great way to test the polarity is use the diode test function that is available on most multimeters.
-When trying to determine rated power the best thing to go off of is the threshold current at which it begins to lase. If you got them from Heruursciences/Hesc_photonics then they are LIKELY from Boston Laser. If you want I can post the specs from them because their site is gone. If they are from other sources I can't help you.
-Turn up the power of a good diode until it dies. Identical diodes should not be run at more than (very) roughly 2/3 of the power at failure.
-IR usually runs at 2.2v, red usually runs at 3v
-The wavelength can sometimes be determined by the color tint of the front facet of the die. For example, if it is half green and half pink(lengthwise) then it is probably an 808nm diode. If it is purple, then it is probably a red diode.

Hope this helps!

Hi there, actually, the batch I have IS from Hesc_photonics, I'm assuming he is some kind of a big player in the laser business and well known for you to just pick the name out of the air, does he post here as well? Do many people purchase from him? What's his story, is he reliable and a good guy or what?

Please do post the info you have, I would very much appreciate it,
Thanks!

 

[More Power]

BDR-203 can handle 300ma at 400mw- 405-G1 lense
BDR-so3 can handle 160ma at 180mw? correct me if im wrong
6x can handle 200ma at 200mw

 

[Grix]

Add this diode: 405nm Nichia 140mW laser diode£­>405nm blue-violet laser£­>Laser&lighting products£­>www.0-like.com

 

[More Power]

wow, at first i thought that was just a 4x but it looks like a whole new diodes come out. Blu ray diode tech is really taking off

 

[HIMNL9]

Niko, you are still searching diodes data, right ?

I just mangl ..... er, "finished to open" an old dvd burner that i was thinking was a 10X (cheap-looking plastic sled, marked DS10HLF, a copper cover on the optics, cheap-looking optics inside .....), and found a SOC in it ..... so, searched a bit around, and found that this same sled appears to be a Sanyo product, used in Philips / Benq and some other burner, some 16X and some 18X, same sled (and in a forum i found someone saying it's also used in a 20X, but no other data, so i'm not sure about this) ..... i'm not totally sure about what this particular burner was, cause it was already half-dismantled waiting for the end , but for sure was a sata lightscribe (it was written on the tray ), and probably (but only probably) was a philips 16X.

Anyway, just made some quick tests, cause i'm working and cannot do them complete right now, it's a red diode , standard pinout (negative case), with a VF of 2.08V at the threshold current, that is 53mA.

If you don't have already the data for these diodes, let me know and i can try to made some pics and a P-I-V sequence for you (if i just figure how much can be a safe/max current for this one )

 

[nikokapo]

Niko, you are still searching diodes data, right ?

I just mangl ..... er, "finished to open" an old dvd burner that i was thinking was a 10X (cheap-looking plastic sled, marked DS10HLF, a copper cover on the optics, cheap-looking optics inside .....), and found a SOC in it ..... so, searched a bit around, and found that this same sled appears to be a Sanyo product, used in Philips / Benq and some other burner, some 16X and some 18X, same sled (and in a forum i found someone saying it's also used in a 20X, but no other data, so i'm not sure about this) ..... i'm not totally sure about what this particular burner was, cause it was already half-dismantled waiting for the end , but for sure was a sata lightscribe (it was written on the tray ), and probably (but only probably) was a philips 16X.

Anyway, just made some quick tests, cause i'm working and cannot do them complete right now, it's a red diode , standard pinout (negative case), with a VF of 2.08V at the threshold current, that is 53mA.

If you don't have already the data for these diodes, let me know and i can try to made some pics and a P-I-V sequence for you (if i just figure how much can be a safe/max current for this one )

YES! Please, do so if you have the time, I'll really appreciate it

Add this diode: 405nm Nichia 140mW laser diode£*>405nm blue-violet laser£*>Laser&lighting products£*>www.0-like.com

Will do, give me some time please.

 

[HIMNL9]

Ok, i found the time for made a measure set, so here are the results (had no time for plot them, sorry)

The diode have no marks of any type, in no places, and it have two square "polarization notches" on the border, with the two "V" shaped ones (where, usually, diodes have one square and 2 "V" shaped ones)

Placed it in an aixiz and hooked to a labby heatsink for keep it ambient temperature (19C), diode at 20 cm from the reading head, dot large 5 mm on the surface of the head, measure procedure for each current value: current to the value -> zero set on LPM -> open head lid -> wait 15 seconds -> read.

mA ----- mW ----- VF (V)
30 ----- 0 ----- 2.00
35 ----- 0 ----- 2.03
40 ----- 0 ----- 2.06
45 ----- 0 ----- 2.08
50 ----- 1 ----- 2.11 <--- here it just start to lase in coherent mode (threshold)
55 ----- 3 ----- 2.13 <--- from here it lase clearly in coherent mode
60 ----- 9 ----- 2.15
65 ----- 14 ----- 2.17
70 ----- 20 ----- 2.19
75 ----- 26 ----- 2.21
80 ----- 30 ----- 2.23
85 ----- 35 ----- 2.25
90 ----- 41 ----- 2.27
95 ----- 46 ----- 2.29
100 ---- 50 ----- 2.31
105 ---- 55 ----- 2.33
110 ---- 61 ----- 2.35
115 ---- 66 ----- 2.37
120 ---- 72 ----- 2.39
125 ---- 76 ----- 2.41
130 ---- 81 ----- 2.43
135 ---- 87 ----- 2.45
140 ---- 92 ----- 2.47
145 ---- 95 ----- 2.49
150 ---- 100 ----- 2.51
155 ---- 106 ----- 2.53
160 ---- 111 ----- 2.55
165 ---- 116 ----- 2.57
170 ---- 121 ----- 2.59
175 ---- 126 ----- 2.61
180 ---- 130 ----- 2.63
185 ---- 135 ----- 2.65
190 ---- 140 ----- 2.66
195 ---- 146 ----- 2.68
200 ---- 151 ----- 2.70
205 ---- 155 ----- 2.72
210 ---- 159 ----- 2.74
215 ---- 164 ----- 2.76
220 ---- 168 ----- 2.78
225 ---- 173 ----- 2.80
230 ---- 177 ----- 2.81
235 ---- 182 ----- 2.83
240 ---- 186 ----- 2.85
245 ---- 190 ----- 2.87
250 ---- 194 ----- 2.89

Having no data about this specific diode, i stopped at 250mA, for now ..... if you know how much current a diode in SOC and with that type of chip (as in the pic) can handle at max, i can redo the test til that current.

 

[nikokapo]

Dude, that is GREAT information.

THANK YOU for taking the time to do it


I will update the list after I take the Probability & Statistics final this Tuesday

Don't worry, I'll plot the data

Also, as much as I'd like to know how much current they can handle, I don't want to ask you to kill your diode and in consequence I'm gonna keep these results.

 

[HIMNL9]

Oops ..... sorry, i just noticed that i forgot to say that i've used a standard aixiz glass lens, not the acrylic one, if you need to know also this, for the comparison ...... my mistake.

In the next days, when i have a little more time, i can make a second set of readings with both types of lenses ..... i really have no ideas about the maximum safe current for this particular diode, i just noticed that seem that, at the last values, the efficency is like decreasing (little less increase of power for the same increase of current, the diode was still at 19C, but i don't know if this is specific of this particular diode, or if some sort of sign that is approaching the maximum current)

By the way, i know that there are other tpes of SOC, like the ones in the 6X sleds ..... anyone know what is the maximum safe current for them ? ..... if is more than 250mA, i can try to push it a bit more ..... i'm never happy to kill an innocent diode, but if it blow, patience .....

Uhm, anyway, i think i can take some reading for current vs time, for see the eventual variations in time ..... the labby heatsink keep it at 19C also at 250mA, so, probably is not a problem to do this in, like, 10 minutes or so of CW .....



EDIT: ok, i made other 2 sets of measures, a little bit more complete, this time, cause in the previous one i not signed the temperature.

This time i've got some little differences, but this time i started with 17C, where instead the start temperature of the previous one was 19C, maybe this difference was due to the temperature ?

Here are the data, both with the same mechanical setup of the previous one, the first set with the glass aixiz lens, and the second set with an acrylic standard aixiz lens, bottom opened

mA ---- mW ---- VF (V)
30 ---- 0 ---- 2.00 <-- 17.0C
35 ---- 0 ---- 2.03
40 ---- 0 ---- 2.06
45 ---- 0 ---- 2.08
50 ---- 1 ---- 2.11
55 ---- 3 ---- 2.13
60 ---- 9 ---- 2.15 <--- 17.0C
65 ---- 14 ---- 2.17
70 ---- 20 ---- 2.19
75 ---- 26 ---- 2.21
80 ---- 30 ---- 2.23
85 ---- 35 ---- 2.25
90 ---- 41 ---- 2.27 <--- 17.1C
95 ---- 46 ---- 2.29
100 --- 50 ---- 2.31
105 --- 55 ---- 2.33
110 --- 61 ---- 2.35
115 --- 66 ---- 2.37
120 --- 72 ---- 2.39 <--- 17.2C
125 --- 76 ---- 2.41
130 --- 81 ---- 2.43
135 --- 87 ---- 2.45
140 --- 92 ---- 2.47
145 --- 95 ---- 2.49
150 --- 100 ---- 2.51 <--- 17.4C
155 --- 106 ---- 2.53
160 --- 111 ---- 2.55
165 --- 116 ---- 2.57
170 --- 121 ---- 2.59
175 --- 126 ---- 2.61
180 --- 130 ---- 2.63 <--- 17.7C
185 --- 135 ---- 2.65
190 --- 140 ---- 2.66
195 --- 146 ---- 2.68
200 --- 151 ---- 2.70
205 --- 155 ---- 2.72
210 --- 159 ---- 2.74 <---- 18.0C
215 --- 164 ---- 2.76
220 --- 168 ---- 2.78
225 --- 173 ---- 2.80
230 --- 178 ---- 2.82
235 --- 183 ---- 2.84
240 --- 188 ---- 2.86 <---- 18.4
245 --- 192 ---- 2.88
250 --- 197 ---- 2.90
255 --- 200 ---- 2.91
260 --- 204 ---- 2.93
265 --- 207 ---- 2.95
270 --- 212 ---- 2.96 <---- 18.9C




mA ---- mW
30 ---- 0 <---- 17.4C
35 ---- 0
40 ---- 0
45 ---- 0
50 ---- 1
55 ---- 3
60 ---- 7 <---- 17.4C
65 ---- 12
70 ---- 16
75 ---- 20
80 ---- 24
85 ---- 28
90 ---- 32 <---- 17.5C
95 ---- 36
100 --- 40
105 --- 44
110 --- 48
115 --- 52
120 --- 56 <---- 17.5C
125 --- 60
130 --- 64
135 --- 68
140 --- 72
145 --- 76
150 --- 79 <---- 17.6C
155 --- 83
160 --- 87
165 --- 91
170 --- 95
175 --- 99
180 --- 102 <---- 17.8C
185 --- 106
190 --- 109
195 --- 113
200 --- 116
205 --- 119
210 --- 122 <---- 18.1C
215 --- 126
220 --- 129
225 --- 133
230 --- 137
235 --- 141
240 --- 144 <---- 18.6C
245 --- 147
250 --- 150
255 --- 153
260 --- 156
265 --- 159
270 --- 164 <---- 19.6C


I marked the temperature only each 6 readings, cause there was not too much variations, except in the last part ..... the temp of the second set is a bit more high, i left all the assembly cool 10 minutes between the 2 sets, but in the meantime also the ambient temperature was changing ..... and not reported the VF in the second measure just cause it was identical to the first one (only one mV of variation in 5 of the points, but can be due to the tolerance of the voltmeter)

As you can see, i pushed the current a bit more, but at 270mA the power reading rised more than the trend, so i imagined that it can be a limit point and stopped here ..... and, by the way, the image of the dot NOT present any "wing" on the slow axis, it's almost perfectly round ..... only a bit oval when defocused to 5mm, but no "wings" nor when focused nor when defocused (defocused both in and out from the focus point, just for check, still no wings)

 

[LASHA4400]

- HELP -

I have one question about my diods
when i fell into pieces a combo drive, i relased 2 laser diodes
on first diode is not any signs of model or text, nothing
and on second is written 47WDd, exactly only this
both diodes are visualy identical
this is that combo drive speeds

and now I need to know which driver can i use for this diodes ?