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 > Optics



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



Reply
 
LinkBack Thread Tools Display Modes
Old 01-07-2011, 07:56 PM #1
Junior Member
 
Join Date: Dec 2010
Posts: 5
Rep Power: 0
Gobc is on a distinguished road
Gobc Gobc is offline
Junior Member
 
Join Date: Dec 2010
Posts: 5
Rep Power: 0
Gobc is on a distinguished road
Default Typical Beam Divergence Rates

Hi Guys,

This is my first laser project and I'm going to be building a mid power blue laser. I'm looking to output 100-200mw. I've already aquired my laser diode and have tested it using a my own little test rig. I was a little surprised that lasers require focusing optics (first time remember). After poking around the internet a bit, It seems like 1.2-1.5mrad is a typical value for beam divergence. Is this true, or are the stats I found from really cheap low quality laser optics?

I calculated that 1.2mrad = 12cm/100yard. This seams extremely large. I know people have been driving leds past 1W, however even at that power output, I can't see imagine the beam being visible past a few hundred meters.


Is it possible to achieve better? Feel free to recommend projects.


Gobc is offline   Reply With Quote







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







Old 01-07-2011, 08:16 PM #2
RA_pierce's Avatar
Class 3B Laser
 
Join Date: Sep 2007
Location: Southern California
Posts: 3,260
Rep Power: 4354
RA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond repute
RA_pierce RA_pierce is online now
Class 3B Laser
RA_pierce's Avatar
 
Join Date: Sep 2007
Location: Southern California
Posts: 3,260
Rep Power: 4354
RA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond repute
Default Re: Typical Beam Divergence Rates

Typical for greens is 1.2-1.5mRad. A good green will be less than 1.2mRad.

Typical for single-mode diodes (405nm and 655nm) with Aixiz focusable lens is 0.5mRad.

Typical for multi-mode diodes (445nm and 808nm) with Aixiz focusable lens is 0.5mRad x 1.6mRad.

Remember that the 445nm diodes have a large emitter that outputs a "stripe" rather than a dot, so each axis has a different divergence angle.

To calculate the beam size over a distance, you need to know:
  • Beam diameter at aperture
  • Beam divergence
  • The distance you are measuring
There is a handy calculator that will do it for you, too:
pseudonomen137's JScript Laser Calculators
RA_pierce is online now   Reply With Quote
Old 01-07-2011, 09:52 PM #3
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,146
Rep Power: 9765
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Cyparagon Cyparagon is online now
Class 4 Laser
Cyparagon's Avatar
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,146
Rep Power: 9765
Cyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond reputeCyparagon has a reputation beyond repute
Default Re: Typical Beam Divergence Rates

Quote:
Originally Posted by Gobc View Post
I calculated that 1.2mrad = 12cm/100yard.
Meters, not yards.
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 01-08-2011, 05:08 PM #4
Class 3R Laser
 
Join Date: Jun 2007
Posts: 1,636
Rep Power: 14605
steve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond repute
steve001 steve001 is offline
Class 3R Laser
 
Join Date: Jun 2007
Posts: 1,636
Rep Power: 14605
steve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond reputesteve001 has a reputation beyond repute
Default Re: Typical Beam Divergence Rates

Quote:
Originally Posted by Gobc View Post
Hi Guys,

This is my first laser project and I'm going to be building a mid power blue laser. I'm looking to output 100-200mw. I've already aquired my laser diode and have tested it using a my own little test rig. I was a little surprised that lasers require focusing optics (first time remember). After poking around the internet a bit, It seems like 1.2-1.5mrad is a typical value for beam divergence. Is this true, or are the stats I found from really cheap low quality laser optics?

I calculated that 1.2mrad = 12cm/100yard. This seams extremely large. I know people have been driving leds past 1W, however even at that power output, I can't see imagine the beam being visible past a few hundred meters.


Is it possible to achieve better? Feel free to recommend projects.
Divergence rate has nothing to do with cheapness. It's just a number. Yes, it is possible to achieve lower divergence. The important question too ask would be is it practical while not spend much $ on beam correction optics. Optics that will circularize the beam plus optics for producing a lower divergence.

100-200mw of blue light from your laser will be significantly brighter then 1W from a blue LED because the laser is collimated and even if the LED is collimated.

To calculate using pseudonomen137's JScript Laser Calculators you'll have to run the numbers twice. Once for the fast axis and once for the slow axis. But before you use the app you'll need to measure at 10 meters what the beam diameter and length are then calcualte the angle of degrees if you want to be precise. Measuring Angles in the Sky
Or you can forget all of that and just experiment with inexpensive optics at first.
steve001 is offline   Reply With Quote
Old 01-08-2011, 05:22 PM #5
Junior Member
 
Join Date: Dec 2010
Posts: 5
Rep Power: 0
Gobc is on a distinguished road
Gobc Gobc is offline
Junior Member
 
Join Date: Dec 2010
Posts: 5
Rep Power: 0
Gobc is on a distinguished road
Default Re: Typical Beam Divergence Rates

Thanks guys. I just wanted to know what a typical laser pointer is capable achieves in terms of divergence. I wouldn't mind a a tighter beam however. Can anybody recommend some optics?
Gobc is offline   Reply With Quote
Old 01-08-2011, 05:46 PM #6
RA_pierce's Avatar
Class 3B Laser
 
Join Date: Sep 2007
Location: Southern California
Posts: 3,260
Rep Power: 4354
RA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond repute
RA_pierce RA_pierce is online now
Class 3B Laser
RA_pierce's Avatar
 
Join Date: Sep 2007
Location: Southern California
Posts: 3,260
Rep Power: 4354
RA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond repute
Default Re: Typical Beam Divergence Rates

Quote:
Originally Posted by steve001 View Post

100-200mw of blue light from your laser will be significantly brighter then 1W from a blue LED because the laser is collimated and even if the LED is collimated.
That is not true. For one, LEDs do not emit monochromatic light, so there is one difference, but assuming the wavelength(s) were the same for the blue laser and the LED, 200mW of laser light is going to be less bright than 1000mW of LED light.

The LED will be less intense since nothing can compete with lasers when it comes to squeezing lots of power in a small area, but if the wavelengths and power is the same, the brightness will be the same.

Quote:
Originally Posted by Gobc View Post
Thanks guys. I just wanted to know what a typical laser pointer is capable achieves in terms of divergence. I wouldn't mind a a tighter beam however. Can anybody recommend some optics?
There aren't many optics sets designed specifically for this (correction and collimation) that are within the average hobbyist's price range, but a beam expander might be close to what you are looking for.

If you want a lens you can simply slap in front of a laser diode and have a great beam, you're going to have a tough time searching. These blue diodes have terrible beam characteristics (although not as bad as some) and are not so easy to tame.

There was a group buy going some time ago for cylindrical correction optics. Your other choice is to collimate the beam with an aspheric lens and use anamorphic prisms to re-shape the output.
RA_pierce is online now   Reply With Quote
Old 01-08-2011, 06:07 PM #7
Junior Member
 
Join Date: Dec 2010
Posts: 5
Rep Power: 0
Gobc is on a distinguished road
Gobc Gobc is offline
Junior Member
 
Join Date: Dec 2010
Posts: 5
Rep Power: 0
Gobc is on a distinguished road
Default Re: Typical Beam Divergence Rates

Quote:
Originally Posted by RA_pierce View Post

There aren't many optics sets designed specifically for this (correction and collimation) that are within the average hobbyist's price range, but a beam expander might be close to what you are looking for.

If you want a lens you can simply slap in front of a laser diode and have a great beam, you're going to have a tough time searching. These blue diodes have terrible beam characteristics (although not as bad as some) and are not so easy to tame.

There was a group buy going some time ago for cylindrical correction optics. Your other choice is to collimate the beam with an aspheric lens and use anamorphic prisms to re-shape the output.

Correct me if I'm wrong, but the collimating lens will make the beam straight, and the asperhic lens will change the shape (from rectangle to circular)?
Gobc is offline   Reply With Quote
Old 01-09-2011, 07:02 AM #8
RA_pierce's Avatar
Class 3B Laser
 
Join Date: Sep 2007
Location: Southern California
Posts: 3,260
Rep Power: 4354
RA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond repute
RA_pierce RA_pierce is online now
Class 3B Laser
RA_pierce's Avatar
 
Join Date: Sep 2007
Location: Southern California
Posts: 3,260
Rep Power: 4354
RA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond reputeRA_pierce has a reputation beyond repute
Default Re: Typical Beam Divergence Rates

Quote:
Originally Posted by Gobc View Post
Correct me if I'm wrong, but the collimating lens will make the beam straight, and the asperhic lens will change the shape (from rectangle to circular)?
No, the aspheric lens would be the "collimating" lens which would reduce the diode's "raw" divergence off the emitter to make the characteristic laser beam.
To change the beam shape to a circle (more or less), either a cylindrical lens or anamorphic prism pair could be used. Another option would be to use fiber optics.
RA_pierce is online now   Reply With Quote
Old 05-23-2012, 01:54 AM #9
Banned
 
Join Date: May 2012
Posts: 107
Rep Power: 0
deathstarlaser can only hope to improve
deathstarlaser deathstarlaser is offline
Banned
 
Join Date: May 2012
Posts: 107
Rep Power: 0
deathstarlaser can only hope to improve
Default Re: Typical Beam Divergence Rates

dang my $5 ebay laser is .8mrad !
deathstarlaser 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


LinkBacks (?)
LinkBack to this Thread: http://laserpointerforums.com/f49/typical-beam-divergence-rates-59627.html
Posted By For Type Date
probe - Long range laser communication beam divergence angle values? - Space Exploration Stack Exchange This thread Refback 10-04-2013 04:24 PM
Jon Rodriguez's answer to Would it be possible to build a residential fiber network in Silicon Valley that would attract enough customers to sustain itself? - Quora This thread Refback 07-17-2012 08:22 PM










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 05:08 AM.


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