Laser pointer discussion. Read/write reviews of laser pointers and laser pointer companies. Learn about all types of laser pointers and lasers





Welcome to Laser Pointer Forums! If you are looking for a laser pointer or want to compare different laser pointer companies, you may want to check out the LPF Laser Pointer Company Database. The link will open in a new window for your convenience.








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers


One laser store meets all your needs

























Go Back   Laser Pointer Forums - Discuss Laser Pointers > Lasers > Buy, Sell, & Trade



LPF List of Laser Pointer Companies (link opens new window)



Reply
 
LinkBack Thread Tools Display Modes
Old 07-31-2016, 07:19 AM #1
Alaskan's Avatar
Class 4 Laser
 
Join Date: Jan 2014
Location: Currently in Iraq.
Posts: 7,075
Rep Power: 48485
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Class 4 Laser
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Currently in Iraq.
Posts: 7,075
Rep Power: 48485
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default Accidentally posted in the wrong section guys, reposted in Optics section.

Edit: I accidentally posted this in the BST section, I didn't think it would make it through approval to end up here, just now see it did. Sorry guys, I later posted the thread in the Optics section titled as "Question for the optics savvy in regard to beam expansion to reduce divergence", after seeing my mistake. Thank you for your answers and help with this question, but I don't want to add to the thread here further, since it is in the wrong section.

Quote:
I'm finding it difficult to find cheap AR coated lenses of the correct focal length for use with beam expansion. However, I have an idea, when using a PCX lens which is too small for the size of the spot hitting it, at its focal length, wouldn't the lens produce the reduced divergence of the spot size it is collimating, even if part of the beam were cut off due to the lens being too small?

To exaggerate the situation, what if I put a 2 inch diameter lens in front of a 6 inch spot, wouldn't that 2 inch lens produce the same divergence of a 6 inch expanded beam, except most of the light is cut off? I'm thinking this might be a way to produce a low divergence beam using a relatively small lens diameter and if the power is high enough, such as from a multimode diode, the trade-off might be advantageous, if not in terms of power delivered at an extreme distance, in terms of reduced size?

Any one know the answer to this? This isn't something I'm finding talked about anywhere yet. Perhaps because it is a hair brained idea and won't work?


__________________

The forum costs more to run than donations received, if you wish to help click this link: http://laserpointerforums.com/donations.htm

Laser Safety: http://www.laserpointersafety.com/index.html

Sam's Laser FAQ: Sam's Laser FAQ: Welcome Page

RHD's Relative Perceived Brightness Calculator. Compare brightness @nm: http://lsrtools.1apps.com/relativebrightness

To shorten my signature I have moved most of my laser related web links to this forum page, the second post in that thread shows most of my builds... Alaskan's Laser Links: http://laserpointerforums.com/f44/al...ml#post1449395


Sincerely investigate any of these three short quotes as new concepts and you've taken your first step into a larger world:

"I regard consciousness as fundamental. I regard matter as derivative from consciousness..." - Max Planck. "Everything we call real is made of things that cannot be regarded as real" - Neils Bohr. "What we call physical things and events do not exist independently of subjective experience..." - Deepak Chopra.

Each of these three rabbit holes go deep, ending up in the same place.

Useless troll fighting.
.........................
PhotoB****t high jacking you too? Use this link instead:
http://imgbb.com

High resolution of my avatar: https://ibb.co/fWOhXF

Last edited by Alaskan; 08-13-2016 at 03:00 AM.
Alaskan is offline   Reply With Quote







LPF List of Laser Pointer Companies (link opens new window)







Old 08-09-2016, 04:16 PM #2
Class 2 Laser
 
Join Date: Jan 2011
Posts: 358
Rep Power: 1116
lazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond repute
lazeristasUVISIR lazeristasUVISIR is offline
Class 2 Laser
 
Join Date: Jan 2011
Posts: 358
Rep Power: 1116
lazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond repute
Default Re: Question for the optics savvy in regard to beam expansion to reduce divergence.

Quote:
Originally Posted by Alaskan View Post
Any one know the answer to this? This isn't something I'm finding talked about anywhere yet. Perhaps because it is a hair brained idea and won't work?
This is out of my interest as I'm not interested in loosing power/energy. However you can look for "truncated Gaussian beams" - there are a lot of theory about it.
__________________
L is for Lasers, and they are good for me.
lazeristasUVISIR is offline   Reply With Quote
Old 08-09-2016, 07:09 PM #3
Eracoy's Avatar
Class 1 Laser
 
Join Date: Jul 2014
Posts: 99
Rep Power: 5834
Eracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond repute
Eracoy Eracoy is online now
Class 1 Laser
Eracoy's Avatar
 
Join Date: Jul 2014
Posts: 99
Rep Power: 5834
Eracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond repute
Default Re: Question for the optics savvy in regard to beam expansion to reduce divergence.

The question you are asking is very similar to the one I ask here. The basic idea, if I understand what you're asking, is to get the "best" (smallest) dot at a distance by expanding farther than the size of your final collimating lens. Yes, if the focal lengths are the same, a big lens and a small one will produce for you the same divergence, just with some truncated.
__________________
405nm 700mW S06J 12X
405nm 800mW BDR-209 16X
405nm 900mW BDR-209 16X
445nm 800mW M140
462nm 1800mW M462
470nm 4W+ NUBM07E
470nm+ 5A NUBM07E
510nm 100mW
520nm 200mW PLP520-B1
520nm 1400mW NDG7475
532nm 300mW
589nm 30mW Spartan
650nm 200mw
650nm 150mw
X10DR 10x Beam Expander
Eracoy is online now   Reply With Quote
Old 08-09-2016, 07:40 PM #4
Class 2 Laser
 
Join Date: Jan 2011
Posts: 358
Rep Power: 1116
lazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond repute
lazeristasUVISIR lazeristasUVISIR is offline
Class 2 Laser
 
Join Date: Jan 2011
Posts: 358
Rep Power: 1116
lazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond repute
Default Re: Question for the optics savvy in regard to beam expansion to reduce divergence.

Quote:
Originally Posted by Eracoy View Post
Yes, if the focal lengths are the same, a big lens and a small one will produce for you the same divergence, just with some truncated.
It would mean that you would get a smaller spot at a far distance. Make a tiny lens, and you would get a focused beam everywhere

That is not right.
__________________
L is for Lasers, and they are good for me.
lazeristasUVISIR is offline   Reply With Quote
Old 08-09-2016, 07:50 PM #5
Eracoy's Avatar
Class 1 Laser
 
Join Date: Jul 2014
Posts: 99
Rep Power: 5834
Eracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond repute
Eracoy Eracoy is online now
Class 1 Laser
Eracoy's Avatar
 
Join Date: Jul 2014
Posts: 99
Rep Power: 5834
Eracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond reputeEracoy has a reputation beyond repute
Default Re: Question for the optics savvy in regard to beam expansion to reduce divergence.

Quote:
Originally Posted by lazeristasUVISIR View Post
It would mean that you would get a smaller spot at a far distance. Make a tiny lens, and you would get a focused beam everywhere

That is not right.
From what I understand, the size of a laser's dot at distance L from a source with divergence θ and size at aperture of D would be:

D + 2 * L * tan(θ/2)

So as D shrinks, yes the dot would get smaller, but the size of the collimating lens wouldn't affect the divergence, so the spot would still have plenty size at distance.
__________________
405nm 700mW S06J 12X
405nm 800mW BDR-209 16X
405nm 900mW BDR-209 16X
445nm 800mW M140
462nm 1800mW M462
470nm 4W+ NUBM07E
470nm+ 5A NUBM07E
510nm 100mW
520nm 200mW PLP520-B1
520nm 1400mW NDG7475
532nm 300mW
589nm 30mW Spartan
650nm 200mw
650nm 150mw
X10DR 10x Beam Expander

Last edited by Eracoy; 08-09-2016 at 07:55 PM.
Eracoy is online now   Reply With Quote
Old 08-09-2016, 08:43 PM #6
Class 2 Laser
 
Join Date: Jan 2011
Posts: 358
Rep Power: 1116
lazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond repute
lazeristasUVISIR lazeristasUVISIR is offline
Class 2 Laser
 
Join Date: Jan 2011
Posts: 358
Rep Power: 1116
lazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond reputelazeristasUVISIR has a reputation beyond repute
Default Re: Question for the optics savvy in regard to beam expansion to reduce divergence.

Quote:
Originally Posted by Eracoy View Post
From what I understand, the size of a laser's dot at distance L from a source with divergence θ and size at aperture of D would be:

D + 2 * L * tan(θ/2)

So as D shrinks, yes the dot would get smaller, but the size of the collimating lens wouldn't affect the divergence, so the spot would still have plenty size at distance.
When you'll start clipping your beam, you need to account the diffraction. Formulas are not that simple.
__________________
L is for Lasers, and they are good for me.
lazeristasUVISIR 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











Loading








Green Laser Pointers by Category Blue Laser Pointers by Category Red Laser Pointers by Category
Yellow Laser Pointers by Category Violet Laser Pointers by Category Orange Laser Pointers by Category
Top Laser Pointers by Power - 1 Watt+ Top Laser Pointers by Power - 500mW+ Top Laser Pointers by Power - 250mW+
Laser Pointer Database High Power Laser Pointers Laser Pointer Diodes






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 03:09 PM.


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