50 mW laser with d&s laser system

On: Tue, Nov 27, 01 11:10:28 PM

Dustin Dooley wrote:

I've just recieved a 50mW panasonic laser from optima optics, and tried it with Mr. DeFreitas laser system and it seems to be working wonderfuly. I havn't tested it for a long period of time yet but the initial tests have been successful. The diode was purchased from the same company that Mr. DeFreitas links to on his D&S laser web page.


Colin Kaminski - Wed, Nov 28, 01 02:17:39 AM

Are you able to measure the output? I have asked Frank what would be involved to change diodes but I have not heard back yet. Let us know how it works out.

Dustin Dooley - Wed, Nov 28, 01 02:19:47 PM

I do not have anything to measure the output, but it seems to be brighter to the eye compared to the 30 mW. The specs match up to the mitsubishi diode very well accept for a few tiny differences wich include, diode reverse voltage 2 max. for the 30mW and 1.5 max. for the 50mW, threshold current 70 mA max. for the 30mW and 50 mA max. for the 50mW, operating current of 120 mA for the 30mW and 115 mA for the 50mW, and the monitor current of .3 mA for the 30mW compared to .1 mA for the 50mW. I'm not an electronics guru but this seems to be tolerable differences. If not please correct me. My d&s system is operating at 2.4 volts to the diode. The 50mW diode typicaly runs in the 2.5 range at 660 nm. Running at 2.4 it should be right at 657 nm. I did nothing to change the circut board and it seems to be working wonderfuly. I just wish I had the numbers off of the laser driver chip Mr. DeFreitas sent so that I could make another circuit he is a smart buisness man and sanded off the info. Sorry Mr. DeFreitas I can't afford another $140 dollar kit no offence, and I hope none is taken.

Colin - Wed, Nov 28, 01 09:39:10 PM

Here is the link to the diode for those interested. http://www.optima-optics.com/LNCQ05PS.htm

Tom B. - Thu, Nov 29, 01 03:49:29 AM

So how does this diode look in an interferometer setup? Fringe contrast and stability, coherence length ... Is it any good for holography?

Joe Farina - Thu, Nov 29, 01 09:50:49 AM

Dustin, The chip in my D&S system is: Sharp IR3C07. This is a chip manufactured by Sharp to drive laser diodes. After a friend of mine chipped off the heatsink which was covering the chip of my D&S system (he's much better with electronics than I am), I was able to read some of the numbers (which were partially concealed through a thin layer of adhesive). It then took a considerable amount of detective work to determine what this chip really was. The full number appears to be IR3C07/N, but, as I recall, the /N part was not on the chip itself. The only other information I have concerning this chip is that it has a maximum driving current of 150mA and a supply voltage of +5. Also, it's "For CD player (Built-in analog APC function)" If you do some serious searching on one of the Sharp websites, you may be able to find a schematic which is a close "match" to the IR3C07/N. That's what I did, and, as I recall, I was satisfied that I found the correct schematic, but it wasn't explicitly stated that it was the IR3C07/N. Sorry, but I don't have a link to the pages where I found this information, but it was on a Sharp website.

Dustin Dooley - Thu, Nov 29, 01 11:55:15 AM

I havn't tested the diode in any sort of way I just received it. I probably won't be able to test it until after christmas when I do I will get back to you. If anyone else purchases the diode and does some testing please post it. I want to thank Joe for his diligent detective work. I do not want to take buisness away from Mr. DeFreitas but just simply want to make another for myself. Thank you very much!

David Asp - Wed, Jan 16, 02 01:40:50 PM

Have you been able to do any more testing with the 50mW diode? I also purchased this diode but have not recieved my D&S Driver kit yet. Also have you been able to put together another D&S system for yourself. Thanks!

Justin Hays - Tue, Feb 26, 02 05:17:38 PM

Hi everyone, On January the 1st of this year, I ordered a Panasonic LNCQ05PS laser diode from Optima Precision. I designed and made some circuit boards around that laser specifically, and finally got to installing the laser itself and doing a "smoke test" ; ) Well, I fired it up last night, everything went beautifully. Except, that, at 2.5V on the diode, the beam (after collimation) looked like something I purchased from the local gas station for $12.00 or so. After collimation, the beam looks identical to your typical red laser pointer when I shot them on the wall next to each other. 5mW in other words. I called Optima about an hour ago, their secretary was extremely rude and as soon as I mentioned the problem, she immediately said "...you must have overpowered it..." I gaurantee you she didn't have a data sheet in front of her. I mean, she could have easily handed me off to someone more qualified but she didn't. She also stated "...there is no way we sent you the wrong laser...". Since when were there 100% perfect people in this world? Anyhow the diode fried at 2.7V which is still below Vmax by the data sheet on the LNCQ05PS. The failure mode was typical, a very low power beam that you can barely see. I emailed Optima just now.........I really hope they do something about this, because I want the 50mW that I payed for. I was really excited last night when I got it working, as it would have been the highest-power that I have worked with up to date. I'm really dissapointed....I wanted to be blinded with 50mW of deep red speckle all over the place. THE SAME THING HAPPENED TO MY FRIEND. He lives about an hour away from me in N. Houston, he tried the laser about a month ago and reports the same thing, about 5mW. Sorry to bother you guys, I accidentally found this list and thought that you would all like to know. I will keep everyone posted if that is okay? Take care, Justin Hays KC5PNP Email: justin@hvguy.com Website: www.hvguy.com (lots of good laser pics all kinds!!)

Dooley - Wed, Feb 27, 02 01:35:38 AM

I have to say that the laser that I received LNCQ05PS using the D&S driver was very bright to say the least. Could it be the driver that you are using is the problem. I had the same problem when I first built a circut i hooked it up and there was little laser power. The problem was that I had forgoten a simple ground wire from the diode. Not saying that this is the problem but simply stating my experience.

Justin Hays - Mon, Aug 26, 02 02:33:35 AM

I am back now after about 6 months! Dooley: I am positive (no pun intended) I had everything hooked up right. My voltages and currents were measured directly across and in line with the diode, respectively. I have years of experience with electronics, and know that my measurements were real. After bugging Optima Precision numerous times to send me the correct diode, they told me to send the diode back for "inspection" to see if it was indeed, fried. And so I did. Me and an engineer there went around with many things. Vmax. Imax. Optical output power (he told me that I absolutely had to use an OPTICAL POWER METER --> the hell if a normal person can't tell how 50mW compares to 5mW! And I AM taking the deeper red wavelength of the LNCQ05PS into account! I knew he'd mention that one, saying "the dot wasn't bright" is kindof asking for it ; ) We also argued about ESD and other crap. Anyhow: so after much effort, the end result was I got screwed out of 50 bucks. Damn them. My best bud got screwed too. He had access to an optical power meter - guess what it read? 5.4mW. That is NOT what we payed for. Justin Hays KC5PNP Email: justin@hvguy.com Website: www.hvguy.com

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