Old 03-10-2015, 10:10 AM #1
gozert's Avatar
Class 3R Laser
 
Join Date: Nov 2014
Location: Netherlands
Posts: 1,092
Rep Power: 277
gozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond repute
gozert gozert is offline
Class 3R Laser
gozert's Avatar
 
Join Date: Nov 2014
Location: Netherlands
Posts: 1,092
Rep Power: 277
gozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond repute
Default Cylindrical and rectangular transverse modes

I've been reading a bit on Wikipedia about the transverse modes on lasers, and have some questions.

So, I've read about there being cylindrical and rectangular transverse modes. I think I know what the difference between the two is, but I don't know which mode applies to a certain kind of laser.

For example, do you get a rectangular transverse mode with a 445nm rectangular beam, or doesn't that have anything to do with it?

Could anyone explain this to me?


__________________
New here? Check this out: All in one thread for beginning hobbyists
gozert is offline   Reply With Quote










Old 03-10-2015, 12:25 PM #2
Robert S's Avatar
Class 1M Laser
 
Join Date: Jan 2015
Location: Germany
Posts: 113
Rep Power: 16
Robert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud of
Robert S Robert S is offline
Class 1M Laser
Robert S's Avatar
 
Join Date: Jan 2015
Location: Germany
Posts: 113
Rep Power: 16
Robert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud ofRobert S has much to be proud of
Default Re: Cylindrical and rectangular transverse modes

Ah, really interesting , i just read through that wiki article, too, didn't understand much of it, though.
Ill keep an eye on this thread.
__________________
405nm china pen not LPM'd
462nm 2.200mW C2 from Bitlasers (2015)
515nm 5mW LP515 from LaserBTB
532nm 350mW Hulk Ultra from Dragonlasers (2009)
532nm 5$ banggood Pen w/o IR filter, not LPM'd
650nm 5mW cheapy Pen
Robert S is offline   Reply With Quote
Old 03-10-2015, 01:31 PM #3
Class 2 Laser
 
Join Date: Jan 2011
Posts: 357
Rep Power: 694
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: 357
Rep Power: 694
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: Cylindrical and rectangular transverse modes

Quote:
Originally Posted by gozert View Post
For example, do you get a rectangular transverse mode with a 445nm rectangular beam, or doesn't that have anything to do with it?
Yup, especially with a low power. The rectangular shape is due to different divergences on perpendicular axes of the beam. With additional optics [like prisms or cylindrical lenses] it can be compensated and the beam become round
The 532-nm laser beams are quite nice round shape, but the mode is rectangular too. Sometimes these lasers have a double beam, that is TEM10.

If you read Transverse mode - Wikipedia, the free encyclopedia you should keep in mind that they take a laser resonator symmetrical and give this formula



A laser diode resonator is not symmetrical in x and y axes. Thus formula for w is dependent on x and y too.
__________________
L is for Lasers, and they are good for me.
lazeristasUVISIR is offline   Reply With Quote
Old 03-10-2015, 02:02 PM #4
gozert's Avatar
Class 3R Laser
 
Join Date: Nov 2014
Location: Netherlands
Posts: 1,092
Rep Power: 277
gozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond repute
gozert gozert is offline
Class 3R Laser
gozert's Avatar
 
Join Date: Nov 2014
Location: Netherlands
Posts: 1,092
Rep Power: 277
gozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond repute
Default Re: Cylindrical and rectangular transverse modes

Quote:
Originally Posted by lazeristasUVISIR View Post
Yup, especially with a low power. The rectangular shape is due to different divergences on perpendicular axes of the beam. With additional optics [like prisms or cylindrical lenses] it can be compensated and the beam become round
The 532-nm laser beams are quite nice round shape, but the mode is rectangular too. Sometimes these lasers have a double beam, that is TEM10.

If you read Transverse mode - Wikipedia, the free encyclopedia you should keep in mind that they take a laser resonator symmetrical and give this formula



A laser diode resonator is not symmetrical in x and y axes. Thus formula for w is dependent on x and y too.
Alright, I think I kind of get it. What I'm wondering though is, there are two images. One of cylindrical and one of rectangular transverse mode. How can I tell when a laser has a cylindrical or rectangular transverse mode? Like you said, a 532nm has a rectangular transverse mode while the dot/beam is about as round as it can get.

Cylindrical:



Rectangular:

__________________
New here? Check this out: All in one thread for beginning hobbyists
gozert is offline   Reply With Quote
Old 03-10-2015, 02:39 PM #5
Class 2 Laser
 
Join Date: Jan 2011
Posts: 357
Rep Power: 694
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: 357
Rep Power: 694
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: Cylindrical and rectangular transverse modes

Quote:
Originally Posted by gozert View Post
How can I tell when a laser has a cylindrical or rectangular transverse mode?
Generally it is a complicated question. In principle, a cylindrical mode can be decomposed into rectangular modes and vice verse.
Look what a math formula is "easiest" to use to define your beam and its propagation.
__________________
L is for Lasers, and they are good for me.
lazeristasUVISIR is offline   Reply With Quote
Old 03-10-2015, 04:08 PM #6
gozert's Avatar
Class 3R Laser
 
Join Date: Nov 2014
Location: Netherlands
Posts: 1,092
Rep Power: 277
gozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond repute
gozert gozert is offline
Class 3R Laser
gozert's Avatar
 
Join Date: Nov 2014
Location: Netherlands
Posts: 1,092
Rep Power: 277
gozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond reputegozert has a reputation beyond repute
Default Re: Cylindrical and rectangular transverse modes

Quote:
Originally Posted by lazeristasUVISIR View Post
Generally it is a complicated question. In principle, a cylindrical mode can be decomposed into rectangular modes and vice verse.
Look what a math formula is "easiest" to use to define your beam and its propagation.
Oh I get it. Not that good with math though, and probably not going to calculate it for every one of my lasers.

Thanks however for the explanation.
__________________
New here? Check this out: All in one thread for beginning hobbyists

Last edited by gozert; 03-10-2015 at 04:09 PM.
gozert 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
Laser Technology Laser Pointer Parts Lasers by Wavelength
Top 10 Laser Pointer Companies Laser Pointer Company Database Visible Beam Laser Pointers






Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 05:29 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