Old 05-30-2014, 01:26 AM #1
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Davis Davis is offline
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Question Small “dot” next to laser spot

Not sure what the term for this is or even if it’s been mentioned before to search on it but I have one of those green Radio Shack lasers that has developed a small little dot next to the spot where the beam shines. It looks like it could be a blemish or dirt but no amount of compressed air or attempts to clean it with lens cleaner, q-tips, etc. get rid of it. Brand new the beam was perfect and this happened to another red laser I had as well and was unable to clear up.

Is there any way to get rid of this?


Davis is offline   Reply With Quote


















Old 05-31-2014, 12:40 PM #2
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Davis Davis is offline
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Default Re: Small “dot” next to laser spot

I'm guessing that this is normal deterioration of the laser components. When brand new you get a perfect little dot which degrades over time.
Davis is offline   Reply With Quote
Old 05-31-2014, 04:03 PM #3
hwang21's Avatar
Class 3R Laser
 
Join Date: Mar 2013
Location: Illinois, USA
Posts: 2,351
Rep Power: 1615
hwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond repute
hwang21 hwang21 is offline
Class 3R Laser
hwang21's Avatar
 
Join Date: Mar 2013
Location: Illinois, USA
Posts: 2,351
Rep Power: 1615
hwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond reputehwang21 has a reputation beyond repute
Default Re: Small “dot” next to laser spot

It could also be that a small bit of the laser beam is hitting the side of the laser host and reflecting, so you get a mini dot next to the main dot
__________________
~405 | ~445 | ~447 | 457.9 | 465.8 | 472.7 | 473 | 476.5 | 487.986 | 496.5 | 501.7 | 514.5 | 532 | 543.5 | 593.5 | 594.1 | 604.6 | 609.07 | 611.9 | 632.816 | ~635 | ~650 | ~660 | ~780 | ~808

Full List Here: https://docs.google.com/spreadsheets...#gid=929099855


"Official WL Historian of LPF" ~Trevor
hwang21 is offline   Reply With Quote
Old 06-01-2014, 01:18 PM #4
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Davis Davis is offline
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Default Re: Small “dot” next to laser spot

If the beam is hitting the side of the laser host I don't know what would cause this other than just carrying the device around. Looking in the housing I can't see anything obvious like a stray particle or scratch. The other laser this happened to I could get to the lens and even after careful cleaning that stray artifact little dot wouldn't go away.
Davis is offline   Reply With Quote
Old 06-01-2014, 08:19 PM #5
upaa27's Avatar
Class 2M Laser
 
Join Date: Jul 2013
Location: San Francisco
Posts: 624
Rep Power: 192
upaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond repute
upaa27 upaa27 is offline
Class 2M Laser
upaa27's Avatar
 
Join Date: Jul 2013
Location: San Francisco
Posts: 624
Rep Power: 192
upaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond reputeupaa27 has a reputation beyond repute
Default Re: Small “dot” next to laser spot

Quote:
Originally Posted by hwang21 View Post
It could also be that a small bit of the laser beam is hitting the side of the laser host and reflecting, so you get a mini dot next to the main dot
Could be this. Also check your lens for anything and make sure it is in place.
upaa27 is offline   Reply With Quote
Old 06-01-2014, 08:38 PM #6
crazyspaz's Avatar
Class 3B Laser
 
Join Date: Jul 2012
Location: IN, United States
Posts: 2,863
Rep Power: 81934
crazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond repute
crazyspaz crazyspaz is online now
Class 3B Laser
crazyspaz's Avatar
 
Join Date: Jul 2012
Location: IN, United States
Posts: 2,863
Rep Power: 81934
crazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond reputecrazyspaz has a reputation beyond repute
Default Re: Small “dot” next to laser spot

does it look something like this?

If so, it just means your laser has "mode hopped" to TEM01- or "transverse electromagnetic mode 01". Normally, manufacturers try to stabilize the DPSS (diode pumped solid state) lasers so that they run in TEM00, which is a perfect round dot. Your little greenie is probably running in a different transverse mode, due to being poorly put together with cheap materials, as are 99% of the chinese lasers out there (yes, yours was made in china). It is not "deterioration of the laser components" as one person said- you would have had to have a lens or crystal deteriorate, which doesn't happen unless the laser is dropped, damaged, etc. So you either have just a typical poorly made laser, or something shifted inside causing a bit of reflection. Can you take a picture of the output? I have seen a few different lasers of mine in TEM01, ranging from a barely distinguishable double oval, to 2 near completely separated dots.

Last edited by crazyspaz; 06-01-2014 at 08:39 PM.
crazyspaz is online now   Reply With Quote
Old 06-01-2014, 11:23 PM #7
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Davis Davis is offline
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Default Re: Small “dot” next to laser spot

The little extra dot is close to the main beam point, like the one in your picture, but it is very tiny, just big enough to be noticeable. The same size scale ratio example of a man hole cover with a dime next to it, the man hole cover representing the main beam dot. I'll try and get a picture.
Davis is offline   Reply With Quote
Old 06-07-2014, 12:48 AM #8
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Davis Davis is offline
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Default Re: Small “dot” next to laser spot

Here's a picture of the tiny extra dot. Its roughly in the 6 o'clock position really close to the main beam dot.
Attached Thumbnails
Small “dot” next to laser spot-laserdot2.jpg  

Last edited by Davis; 06-07-2014 at 10:37 AM. Reason: added detail, tried to post a larger image but couldn't figure it out
Davis is offline   Reply With Quote
Old 06-08-2014, 09:01 AM #9
ultimatekaiser's Avatar
Class 3B Laser
 
Join Date: Mar 2013
Location: Colorado, USA
Posts: 2,797
Rep Power: 3433735
ultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond repute
Send a message via Skype™ to ultimatekaiser
ultimatekaiser ultimatekaiser is online now
Class 3B Laser
ultimatekaiser's Avatar
 
Join Date: Mar 2013
Location: Colorado, USA
Posts: 2,797
Rep Power: 3433735
ultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond reputeultimatekaiser has a reputation beyond repute
Send a message via Skype™ to ultimatekaiser
Default Re: Small “dot” next to laser spot

Quote:
Originally Posted by Davis View Post
Here's a picture of the tiny extra dot. Its roughly in the 6 o'clock position really close to the main beam dot.
looks like an internal reflection. could be from in the laser host, also possible that it is from one of the internal optical surfaces. Have you dropped or bumped it into anything? its possible one of the surfaces is just ever so slightly out of line.
ultimatekaiser is online now   Reply With Quote
Old 06-14-2014, 03:06 AM #10
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Davis Davis is offline
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Default Re: Small “dot” next to laser spot

I carry it in a pocket and thought it was accumulated dust or something. Maybe banging against something else in the pocket, keys, change, etc.? I chalked it up to poor quality or cheap parts. The same thing happened with a red RS laser I had years ago.
Davis is offline   Reply With Quote
Old 06-17-2014, 08:29 PM #11
Member
 
Join Date: Dec 2011
Location: Vermont, USA
Posts: 46
Rep Power: 0
bostjan is just really nicebostjan is just really nicebostjan is just really nicebostjan is just really nice
bostjan bostjan is offline
Member
 
Join Date: Dec 2011
Location: Vermont, USA
Posts: 46
Rep Power: 0
bostjan is just really nicebostjan is just really nicebostjan is just really nicebostjan is just really nice
Default Re: Small “dot” next to laser spot

All of my Radio Shack lasers have done this. I, too, believe it is due to poorly made optics/poor alignment of components. There isn't really a good way that I know of to fix it. Just stay away from $30 radio Shack lasers, which are, in my opinion, inferior even to the cheapest eBay pens (which typically go for 1/3 or less of the price).
bostjan is offline   Reply With Quote
Old 06-21-2014, 01:02 PM #12
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Davis Davis is offline
Junior Member
 
Join Date: May 2014
Posts: 7
Rep Power: 0
Davis is on a distinguished road
Default Re: Small “dot” next to laser spot

At a distance the extra little dot isn't noticeable but the fact that the extra dot is there is somewhat annoying. I can live with it. My next laser might be a better quality yellow laser but I still need to do some research as to beam viability, range, cost, vendor, etc.
Davis 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 03:56 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