Old 01-03-2008, 05:12 PM #1
TheMonk's Avatar
Class 2M Laser
 
Join Date: Aug 2007
Location: Virginia, USA
Posts: 750
Rep Power: 2680
TheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond repute
TheMonk TheMonk is offline
Class 2M Laser
TheMonk's Avatar
 
Join Date: Aug 2007
Location: Virginia, USA
Posts: 750
Rep Power: 2680
TheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond repute
Default Pulsar NO Wings "-o-"

I notice from this beam shot the Pulsar does not have Wings "-o-" on each side of the beam.
http://www.laserpointerforums.com/fo...=1198452059/15

All my DIY Red Burners regardless Open or Close Can Diodes have Wings on each side.

Is the Pulsar using a different type of Diode, or a small aperture collimation lens to block the Wings?


TheMonk is offline   Reply With Quote


















Old 01-03-2008, 05:45 PM #2
likewhat
Guest
 
Posts: n/a
likewhat
Guest
 
Posts: n/a
Default Re: Pulsar NO Wings "-o-"

The output of diodes is elliptical kinda like a football instead of being round. You can correct it and make it look round by using something called an anamorphic prism pair. I didnt really understand what you were talking about from the picture you posted but that is what I assume you are talking about. Whatever a pulsar is probably has an anamorphic prism pair in it to correct the football shape and make it round.

Also, here is a link to anamorphic prism pairs from thorlabs

http://www.thorlabs.com/NewGroupPage...TOKEN=98779961
  Reply With Quote
Old 01-03-2008, 06:07 PM #3
Class 3R Laser
 
Join Date: Oct 2006
Posts: 2,032
Rep Power: 32
pseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud of
pseudonomen137 pseudonomen137 is offline
Class 3R Laser
 
Join Date: Oct 2006
Posts: 2,032
Rep Power: 32
pseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud of
Default Re: Pulsar NO Wings "-o-"

Quote:
Originally Posted by likewhat
The output of diodes is elliptical kinda like a football instead of being round. You can correct it and make it look round by using something called an anamorphic prism pair. I didnt really understand what you were talking about from the picture you posted but that is what I assume you are talking about. Whatever a pulsar is probably has an anamorphic prism pair in it to correct the football shape and make it round.

Also, here is a link to anamorphic prism pairs from thorlabs

http://www.thorlabs.com/NewGroupPage...TOKEN=98779961
Haha, pulsar with anamorphic prisms? Naah, they didnt even bother sticking a driverboard in that thing (its a pen-form red unit running direct off 2xAAAs).

I'm not sure what causes it, I've heard it may be from running the diode a little too hard, but its not the elliptical shape of the profile. Its like a dot with a line through it - perfectly through the center. At first it would seem like a scratch on a lens, but its not, and I have NO IDEA what the heck does cause it.
pseudonomen137 is offline   Reply With Quote
Old 01-03-2008, 06:36 PM #4
TheMonk's Avatar
Class 2M Laser
 
Join Date: Aug 2007
Location: Virginia, USA
Posts: 750
Rep Power: 2680
TheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond repute
TheMonk TheMonk is offline
Class 2M Laser
TheMonk's Avatar
 
Join Date: Aug 2007
Location: Virginia, USA
Posts: 750
Rep Power: 2680
TheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond repute
Default Re: Pulsar NO Wings "-o-"

Quote:
Originally Posted by pseudonomen137
[quote author=likewhat link=1199383942/0#1 date=1199385932]The output of diodes is elliptical kinda like a football instead of being round. You can correct it and make it look round by using something called an anamorphic prism pair. I didnt really understand what you were talking about from the picture you posted but that is what I assume you are talking about. Whatever a pulsar is probably has an anamorphic prism pair in it to correct the football shape and make it round.

Also, here is a link to anamorphic prism pairs from thorlabs

http://www.thorlabs.com/NewGroupPage...TOKEN=98779961
Haha, pulsar with anamorphic prisms? Naah, they didnt even bother sticking a driverboard in that thing (its a pen-form red unit running direct off 2xAAAs).

I'm not sure what causes it, I've heard it may be from running the diode a little too hard, but its not the elliptical shape of the profile. Its like a dot with a line through it - perfectly through the center. At first it would seem like a scratch on a lens, but its not, and I have NO IDEA what the heck does cause it.[/quote]

Do you think a very small aperture hole on the collimation lens was used to block out all the artifacts and make the beam nice and round?
TheMonk is offline   Reply With Quote
Old 01-03-2008, 06:50 PM #5
roSSco's Avatar
Class 2M Laser
 
Join Date: Dec 2007
Posts: 649
Rep Power: 182787
roSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond repute
roSSco roSSco is offline
Class 2M Laser
roSSco's Avatar
 
Join Date: Dec 2007
Posts: 649
Rep Power: 182787
roSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond reputeroSSco has a reputation beyond repute
Default Re: Pulsar NO Wings "-o-"

My DIY does the same thing.
roSSco is offline   Reply With Quote
Old 01-03-2008, 06:55 PM #6
knimrod's Avatar
Class 2 Laser
 
Join Date: Nov 2007
Location: Lansing, MI
Posts: 385
Rep Power: 14
knimrod is a jewel in the roughknimrod is a jewel in the roughknimrod is a jewel in the rough
knimrod knimrod is offline
Class 2 Laser
knimrod's Avatar
 
Join Date: Nov 2007
Location: Lansing, MI
Posts: 385
Rep Power: 14
knimrod is a jewel in the roughknimrod is a jewel in the roughknimrod is a jewel in the rough
Default Re: Pulsar NO Wings "-o-"

He's referring to this:


A while back, I started a thread on it here: http://www.laserpointerforums.com/fo...num=1195435478
__________________
I never give them hell. I just tell the truth and they think it's hell. - Harry S. Truman
knimrod is offline   Reply With Quote
Old 01-03-2008, 07:09 PM #7
likewhat
Guest
 
Posts: n/a
likewhat
Guest
 
Posts: n/a
Default Re: Pulsar NO Wings "-o-"

Oh, that is weird. I have never seen a diode do that before, but since everyone who has that type of diode sees the same thing it is probably related to that model/make of diode.

On the mention of putting in a aperture to rounden it up, that would give you a round dot surrounded by a bunch of rings. You cant filter astigmatism out of a beam, you have to correct it.
  Reply With Quote
Old 01-03-2008, 07:35 PM #8
TheMonk's Avatar
Class 2M Laser
 
Join Date: Aug 2007
Location: Virginia, USA
Posts: 750
Rep Power: 2680
TheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond repute
TheMonk TheMonk is offline
Class 2M Laser
TheMonk's Avatar
 
Join Date: Aug 2007
Location: Virginia, USA
Posts: 750
Rep Power: 2680
TheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond reputeTheMonk has a reputation beyond repute
Default Re: Pulsar NO Wings "-o-"

Beam Shot from Pulsar 150.
Attached Thumbnails
Pulsar NO Wings "-o-"-pulsar-beam.jpg  
TheMonk is offline   Reply With Quote
Old 01-03-2008, 11:10 PM #9
flogged's Avatar
Class 2M Laser
 
Join Date: Jul 2007
Posts: 530
Rep Power: 48
flogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond repute
flogged flogged is offline
Class 2M Laser
flogged's Avatar
 
Join Date: Jul 2007
Posts: 530
Rep Power: 48
flogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond reputeflogged has a reputation beyond repute
Default Re: Pulsar NO Wings "-o-"

Quote:
Originally Posted by pseudonomen137

I'm not sure what causes it, I've heard it may be from running the diode a little too hard, but its not the elliptical shape of the profile. Its like a dot with a line through it - perfectly through the center. At first it would seem like a scratch on a lens, but its not, and I have NO IDEA what the heck does cause it.
I think the line is caused by light diffracting around the 'fast axis' of the LD. In a LD the lasing cavity is constrained by the nature of the PN junction (very thin, 'pancake' shaped). If you set the focus to infinity and project the spot onto a wall 20-30 feet away an uncorrected single mode diode (using a no beam correction optics) will project an elliptical spot. The long part of the ellipse projects from the narrow part of the emitter rectangle - the smaller aperture causes more diffraction. See the diagram. The faint line may also have to do with the bragg grating used to enforce a single mode in most of these diodes.

Basically the line is an artifact intrinsic to the construction of these diodes. Most manufacturers offer upscale laser diode modules that have optics that correct the spot to a nice round dot, but then they cost $$$. Anyway it's really a cosmetic thing as over 95% of the energy will be in the central ellipse even for a relatively 'dirty' beam.

Not certain why the pulsar doesn't show it.


flogged is offline   Reply With Quote
Old 01-03-2008, 11:48 PM #10
knimrod's Avatar
Class 2 Laser
 
Join Date: Nov 2007
Location: Lansing, MI
Posts: 385
Rep Power: 14
knimrod is a jewel in the roughknimrod is a jewel in the roughknimrod is a jewel in the rough
knimrod knimrod is offline
Class 2 Laser
knimrod's Avatar
 
Join Date: Nov 2007
Location: Lansing, MI
Posts: 385
Rep Power: 14
knimrod is a jewel in the roughknimrod is a jewel in the roughknimrod is a jewel in the rough
Default Re: Pulsar NO Wings "-o-"

When observing this phenomena with the several diodes that I have, this artifact seems to come and go randomly. Sometimes it's very pronounced, sometimes faintly visible, and sometimes not there at all. At times, you can actually watch it fade in and out.
__________________
I never give them hell. I just tell the truth and they think it's hell. - Harry S. Truman
knimrod is offline   Reply With Quote
Old 01-04-2008, 12:55 AM #11
Class 1 Laser
 
Join Date: Aug 2007
Posts: 62
Rep Power: 12
AndrewAZ is on a distinguished road
AndrewAZ AndrewAZ is offline
Class 1 Laser
 
Join Date: Aug 2007
Posts: 62
Rep Power: 12
AndrewAZ is on a distinguished road
Default Re: Pulsar NO Wings "-o-"

The picture posted has them you just cant see it since the laser dot was taken at such close range (notice the stat of one of -0- on the top left of the dot), my pulsar 75 had it and my new modded pulsar from pseudonomen137 has it.
AndrewAZ is offline   Reply With Quote
Old 01-05-2008, 06:43 PM #12
Class 3R Laser
 
Join Date: Nov 2007
Posts: 1,047
Rep Power: 457
wooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond repute
wooooooolazer wooooooolazer is offline
Class 3R Laser
 
Join Date: Nov 2007
Posts: 1,047
Rep Power: 457
wooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond reputewooooooolazer has a reputation beyond repute
Default Re: Pulsar NO Wings "-o-"

I think i found something important... http://www.laserpointerforums.com/fo...num=1161648423

Skip past the first post and look at the second, he says that once that hole was made bigger that line apeared, so aperantly the pulsar does it to, the hole just blocks the line.

..lazer... ;D ;D ;D
wooooooolazer is offline   Reply With Quote
Old 01-05-2008, 08:13 PM #13
Class 3R Laser
 
Join Date: Oct 2006
Posts: 2,032
Rep Power: 32
pseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud of
pseudonomen137 pseudonomen137 is offline
Class 3R Laser
 
Join Date: Oct 2006
Posts: 2,032
Rep Power: 32
pseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud ofpseudonomen137 has much to be proud of
Default Re: Pulsar NO Wings "-o-"

I think that must have just been a coincidence. I've have ones with the hole englarged that don't do it, as well as ones with the small holes that do do it.
pseudonomen137 is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



























Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 11:05 PM.


Powered by: vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC