cad@speedy.cs.wisc.edu (Owner of VLSI software) (03/25/88)
Hey, optics gurus! How much current should be put through a laser diode from a compact disc player? 200ma is my guess (a friend used about 1.2A and it slowly got dimmer). Thanks, Chris Schumann chris@leyden.cs.wisc.edu (Mail to this address if possible)
tedk@ihuxv.ATT.COM (Kekatos) (03/26/88)
In article <5451@spool.cs.wisc.edu| cad@speedy.cs.wisc.edu (Owner of VLSI software) writes: |Hey, optics gurus! | |How much current should be put through a laser diode from |a compact disc player? | |200ma is my guess (a friend used about 1.2A and it slowly |got dimmer). | |Thanks, |Chris Schumann chris@leyden.cs.wisc.edu |(Mail to this address if possible) I didn't think that the laser diodes were VISIBLE. Are you sure that it is visible?? I think it is Infra-Red Ted G. Kekatos backbone!ihnp4!ihuxv!tedk (312) 979-0804 AT&T Bell Laboratories, Indian Hill South, IX-1F-460 Naperville & Wheaton Roads - Naperville, Illinois. 60566 USA
wte@ncrcae.Columbia.NCR.COM (Bill Eason) (03/28/88)
In article <2547@ihuxv.ATT.COM> tedk@ihuxv.UUCP (55624-Kekatos,T.G.) writes: >In article <5451@spool.cs.wisc.edu| cad@speedy.cs.wisc.edu (Owner of VLSI software) writes: >|How much current should be put through a laser diode from >|a compact disc player? >| >|200ma is my guess (a friend used about 1.2A and it slowly >|got dimmer). > >I didn't think that the laser diodes were VISIBLE. Are you >sure that it is visible?? I think it is Infra-Red Even infrared light is visible at high power, isn't it? Maybe pumping 1.2A of current into a diode made the IR visible (for a while). As to why it got dimmer? High powered light sources (like the sun, for example) tend to appear dimmer when you stare at them long enough :~) just a thought.... ============================================================================== Bill Eason (803) 791-6917 ...!ucbvax!sdcsvax!ncr-sd!ncrcae!util5!wte NCR Corporation ...!rutgers!mcnc!ece-csc!ncrcae!util5!wte E & M Columbia 3325 Platt Springs Rd. West Columbia, SC 29169 ============================================================================== -- Bill Eason (803) 791-6917 ...!ucbvax!sdcsvax!ncr-sd!ncrcae!util5!wte NCR Corporation ...!rutgers!mcnc!ece-csc!ncrcae!util5!wte E & M Columbia 3325 Platt Springs Rd. West Columbia, SC 29169
cad@speedy.cs.wisc.edu (Owner of VLSI software) (03/29/88)
In article <2547@ihuxv.ATT.COM>, tedk@ihuxv.ATT.COM (Kekatos) writes: > I wrote: ... > |200ma is my guess (a friend used about 1.2A and it slowly > |got dimmer). > > I didn't think that the laser diodes were VISIBLE. Are you > sure that it is visible?? I think it is Infra-Red > Ted G. Kekatos Well it was visible, although I suspect that most of the energy was in the infrared spectrum. (I though lasers were supposed to be monochromatic)? The collumator (sp?) and semi-reflective mirror may have shifted the frequency of the laser to be barely visible it was never bright (never close to an LED), but if we turned out all the lights and waited for our eyes to adjust, we could just make out a little spot of red on a sheet of paper. Chris Schumann chris@leyden.cs.wisc.edu
ssr@cos.com (Dave Kucharczyk) (03/29/88)
>>In article <5451@spool.cs.wisc.edu| cad@speedy.cs.wisc.edu (Owner of VLSI software) writes: >>|How much current should be put through a laser diode from >>|a compact disc player? >>| >>|200ma is my guess (a friend used about 1.2A and it slowly >>|got dimmer). >> More than likely it was getting dimmer because it was burning up, very much like LED's do. I believe that CD players use pulsed diodes, which will be destroyed if you apply DC to them for any appreciable amount of time. dave
jnp@calmasd.GE.COM (John Pantone) (03/30/88)
> Well it was visible, although I suspect that most of the energy > was in the infrared spectrum. (I though lasers were supposed > to be monochromatic)? Not necessarily monochromatic (although many are very nearly so), but coherent (light waves "in step", making the construction of very nearly zero-spreading beams possible (collumnated (sp?))). Most laser diodes are, indeed, principally active in the infra-red, quite a few, however, emit a detectable red light.-- These opinions are solely mine and in no way reflect those of my employer. John M. Pantone @ GE/Calma R&D, 9805 Scranton Rd., San Diego, CA 92121 ...{ucbvax|decvax}!sdcsvax!calmasd!jnp jnp@calmasd.GE.COM GEnie: J.PANTONE
henry@utzoo.uucp (Henry Spencer) (03/31/88)
> Well it was visible, although I suspect that most of the energy > was in the infrared spectrum... > it was never bright (never close to an LED), but if we > turned out all the lights and waited for our eyes to > adjust, we could just make out a little spot of red > on a sheet of paper. Remember that there is no sharp dividing line between visible light and infrared. There is no frequency above which the stuff is visible and below which it is not; the sensitivity of the eye simply gets poorer and poorer as the frequency gets lower. Eventually sensitivity falls to essentially zero, but it's a gradual decline rather than a sharp transition. Near-visible infrared is not completely invisible, especially in favorable conditions (bright source, darkened room). -- "Noalias must go. This is | Henry Spencer @ U of Toronto Zoology non-negotiable." --DMR | {allegra,ihnp4,decvax,utai}!utzoo!henry
joel@mit-amt.MEDIA.MIT.EDU (joel s. kollin) (04/02/88)
Please be careful around invisible lights sources in general, and lasers in particular. In order to see near IR radiation, you'll probably have a LOT of it entering your eye, and if the source is collimated it will come to a focus at the back of your retina. This can cause damage at VERY LOW power levels. I haven't played with laser diodes but I do work with gas lasers, and have heard enough horror stories. Please read up on the safety considerations for IR lasers and buy the proper eauipment. I believe you can purchase a material which converts the IR into visible light, and presumably diffuses it too. I think it's relatively inexpensive. joel
frederit@boulder.Colorado.EDU (FREDERICKS THOMAS M) (10/12/89)
I just ordered some laser diodes from Unicorn Electronics. The add said they are SB1053's. Since they were only 10.00 apiece I thought they would be neat to experiment with. Questions: 1) Does anyone know who makes them? Maybe they also make a driver chip for it. 2) Are these just junk, or has someone out there actually used them? BTW if anyone is interested, the add is in the back of the new BYTE IBM Edition. Thanks, Tom... ------------------------------------------------------------------------------- Enter the point where reality and illusion merge to become one... tomf@boulder.colorado.edu -------------------------------------------------------------------------------
frankb@hpsad.HP.COM (Frank Ball) (10/14/89)
Subject: Laser Diodes I just ordered some laser diodes from Unicorn Electronics. The add said they are SB1053's. Since they were only 10.00 apiece I thought they would be neat to experiment with. tomf@boulder.colorado.edu ------------------------------------------------------------------------------- It sounds like a good price. Are they visable light or infared?? Frank Ball 2LR-O frankb@hpsad.HP.COM Hewlett Packard (707) 794-4168 1212 Valley House Drive fax: (707) 794-4452 Rohnert Park CA 94928-4999 I'm the NRA.