Well, yes you are right. We have many models or approximations of the physical worlds behaviour that are applicable in many situations and break down in others. In optics thinking of those rays of light travelling in straight lines is fine much of the time.
I do totally agree with you all about the wide arc in space produced by waving a laser.
1.A puzzling, often paradoxical statement, anecdote, question, or verbal exchange, used in Zen Buddhism as an aid to meditation and a means of gaining spiritual awakening.
Now it's you guys' turn to show off a few lasers in a project. Otherwise, you're just hoarding.
I tried aligning a couple of lasers to make a horizontal line. They projected all over the wall (high and low, uneven spacing). Not a lot of consistency here but what can you expect for 22 cents...
I guess you experienced that trying to make your square.
I used a drill press for seven lasers in a row. They fit tightly into the holes, but you can see they don't exactly line up!
I guess you experienced that trying to make your square.
I used a drill press for seven lasers in a row. They fit tightly into the holes, but you can see they don't exactly line up!
Yes, I also found that the beam was not parallel with the cylindrical laser diode to varying degrees over the four units I used. Maybe that's why they are discounted so heavily. Didn't slow me down though, I expected that. The photo shows my unit after assembly with all lasers on whilst being glued into alignment.
My app was to project laser dots on the seabed for calibration of a subsurface camera image. Perhaps I was not so crazy to order the more expensive ($2) lasers after all!
... aligning a couple of lasers.. they don't exactly line up!
1) drill holes in you mounting material
2) make a pencil rubbing of the holes
3) stick the mounted lasers on the wall on one side of the room
4) stick the paper on the wall on the other side of the room.
5) adjust the lasers (i used shims and little drywall screws) so each dot is centered on the corresponding hole image on the paper.
Once the beam are pretty parallel, your done. eventually they willdiverge, but they will be farther away than you can see. I never found a far enough target to use a telescope, I live in the plains. Maybe somebody by mountains cn do better.
I used a thin plate, press fit holes and CA to affix lasers after alignment as shown a few posts back. Keep CA & kicker far from laser lens, the fumes can fog the lens.
My $2.11 purchase led to another, far more expensive purchase. When I looked at the 21-cent variety, I realized that they do not have focussing lenses. So I also sprung for ten of these:
Mine arrived. I'm not sure when, I don't receipt my eBay items when they arrive but it was probably at least a week or more since I got them. I have been into Ebay to update feedback on them and I know it's been more than a week since I did feedback.
Quick someone point two lasers at each other fiber optic optional, using power transistors if necessary, but also include a tap off the laser diodes to the prop to detect discharge for use as button.
A quick way to do it is run RCTIME function on proper leg of detector diode, with other leg held H or L during desired detection window, watch rctime output as number in debug to determine if any deviation when lasing the cavity of a identical laser.
Have emitter laser pulse at known interval. Watch for interval. Reciever may need to pulse also to cause bidirectional photonic phase lock.
IF you get a bidirectional photonic phase lock in your laser cavities, vary the period and monitor the opposite diode anode/cathode for response.
I fried 7 (out of the 20 I ordered) lasers (wired in parallel) by accidentally reversing the voltage :sick:.
So I ordered another 20, which I got this week.
I just ordered some Vishay TEPT5600 ambient light phototransistors. Their peak wave length sensitivity is 570nm and the infrared spectrum is suppressed.
I'm hoping they will make good sensors for the lasers' 650nm.
30 kW, eh? Assuming these laser diodes are 5 mW each (?) then we'd need what, 6 million of them to make 30 kW? That's $1.26 million plus a bit of wiring and alignment labor.
Comments
Who is "Rich"?
Well, yes you are right. We have many models or approximations of the physical worlds behaviour that are applicable in many situations and break down in others. In optics thinking of those rays of light travelling in straight lines is fine much of the time.
I do totally agree with you all about the wide arc in space produced by waving a laser.
-Phil
koan
Houghton Mifflin
n.noun
1.A puzzling, often paradoxical statement, anecdote, question, or verbal exchange, used in Zen Buddhism as an aid to meditation and a means of gaining spiritual awakening.
It really is my call sign, and no, we don't look too similar.
http://forums.parallax.com/showthread.php/157586-Laser-Tracker-Pan-amp-Tilt?p=1295399#post1295399
You deserve a few for that demo.
I tried aligning a couple of lasers to make a horizontal line. They projected all over the wall (high and low, uneven spacing). Not a lot of consistency here but what can you expect for 22 cents...
I guess you experienced that trying to make your square.
I used a drill press for seven lasers in a row. They fit tightly into the holes, but you can see they don't exactly line up!
Yes, I also found that the beam was not parallel with the cylindrical laser diode to varying degrees over the four units I used. Maybe that's why they are discounted so heavily. Didn't slow me down though, I expected that. The photo shows my unit after assembly with all lasers on whilst being glued into alignment.
-Phil
1) drill holes in you mounting material
2) make a pencil rubbing of the holes
3) stick the mounted lasers on the wall on one side of the room
4) stick the paper on the wall on the other side of the room.
5) adjust the lasers (i used shims and little drywall screws) so each dot is centered on the corresponding hole image on the paper.
Once the beam are pretty parallel, your done. eventually they willdiverge, but they will be farther away than you can see. I never found a far enough target to use a telescope, I live in the plains. Maybe somebody by mountains cn do better.
Anybody else got this item?. I' still waiting.
Jim
http://www.ebay.com/itm/NEW-Adjustable-650nm-5mW-Red-Laser-Module-Focus-Laser-Head-Focalize-Punctiform-/291165255844?ssPageName=ADME:L:OC:US:3160
-Phil
Re: your last post. Same laser, same seller.
If a laser can talk to a laser at fairly useful speeds.... at these prices...
Ive never tried to apply the" https://en.wikipedia.org/wiki/Forrest_Mims#Using_LEDs_as_narrow_band_light_sensors " method to laser diodes.
DOO EEEIT.
A quick way to do it is run RCTIME function on proper leg of detector diode, with other leg held H or L during desired detection window, watch rctime output as number in debug to determine if any deviation when lasing the cavity of a identical laser.
Have emitter laser pulse at known interval. Watch for interval. Reciever may need to pulse also to cause bidirectional photonic phase lock.
IF you get a bidirectional photonic phase lock in your laser cavities, vary the period and monitor the opposite diode anode/cathode for response.
So I ordered another 20, which I got this week.
I just ordered some Vishay TEPT5600 ambient light phototransistors. Their peak wave length sensitivity is 570nm and the infrared spectrum is suppressed.
I'm hoping they will make good sensors for the lasers' 650nm.
Do not point a IR laser diode at it just after adding any one of these compounds,,,
Boy, they are big un's.
30 kW, eh? Assuming these laser diodes are 5 mW each (?) then we'd need what, 6 million of them to make 30 kW? That's $1.26 million plus a bit of wiring and alignment labor.