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 > Laser Measurements



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



Reply
 
LinkBack Thread Tools Display Modes
Old 07-22-2012, 09:52 PM #33
Blord's Avatar
Class 4 Laser
 
Join Date: Dec 2007
Location: Belgium
Posts: 5,368
Rep Power: 770
Blord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond repute
Blord Blord is offline
Class 4 Laser
Blord's Avatar
 
Join Date: Dec 2007
Location: Belgium
Posts: 5,368
Rep Power: 770
Blord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

I have tried the reflection method from Cyparagon to reduce the power of the beam. I have mixed results of this method. My test laser was a mid power 445nm M140 diode.
Measuring directly on my LPM the output was 888mW. When I use a glass in 45 degree angle to the LPM the measurement depends on the axial rotation of the laser !
First I use both reflected dots on the sensor. The second dot came from the other side of the glass. This side creates a second dot.
When the dot are in the vertical position the output is only 16mW. This is the setup in the picture.
But I rotate the laser 90 degree axially the output is suddenly 134mW !!!
The differences make the calculation very hard. A slightly turned laser could yield a different output.

Somehow the coherent nature of laser interfere with glass surface.
I think this method create an unnecessary factor in the LPM measurement.


Don't mind the LPM reading but look at the position of the dot.


__________________
405nm 400mW S06J C6
445nm 3W Big Boy, 2.8W Dominator, 2.4W Steel Laser
450nm 240mW PL450 C6
473nm 100mW PGL-III-C-473
520nm 55mW Skylaser PL520
532nm 821mW Skylaser PL532, 133mW Jetlasers Ti-B
589nm 100mW PGL-III-C-589
635nm 70mW Sanyo SenTorch
638nm 175mW Ehgemus, 1W Rook
660nm 1216mW Skylaser PL660, 263mW LPC826 C6
685nm 33mW Fujitsu FLD6A2TK C6
780nm 150mW Dilda
808nm 640mW C6

I have copper 501B and Dominator lasers for sale !
Blord is offline   Reply With Quote







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







Old 07-22-2012, 10:06 PM #34
ryansoh3's Avatar
Class 3R Laser
 
Join Date: Feb 2012
Location: Pittsburgh
Posts: 1,282
Rep Power: 276
ryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond repute
ryansoh3 ryansoh3 is offline
Class 3R Laser
ryansoh3's Avatar
 
Join Date: Feb 2012
Location: Pittsburgh
Posts: 1,282
Rep Power: 276
ryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

Quote:
Originally Posted by Blord View Post
I have tried the reflection method from Cyparagon to reduce the power of the beam. I have mixed results of this method. My test laser was a mid power 445nm M140 diode.
Measuring directly on my LPM the output was 888mW. When I use a glass in 45 degree angle to the LPM the measurement depends on the axial rotation of the laser !
First I use both reflected dots on the sensor. The second dot came from the other side of the glass. This side creates a second dot.
When the dot are in the vertical position the output is only 16mW. This is the setup in the picture.

But I rotate the laser 90 degree axially the output is suddenly 134mW !!!
The differences make the calculation very hard. A slightly turned laser could yield a different output.

Somehow the coherent nature of laser interfere with glass surface.
I think this method create an unnecessary factor in the LPM measurement.



Don't mind the LPM reading but look at the position of the dot.
Hmm... I'm just a bit confused because you said that in the picture, the dots are vertical.

However, I'm only seeing two horizontal dots on the LPM sensor, side by side.


Now, this doesn't make much sense. What the heck could be causing this effect?

Thanks for experimenting. Cheers!
__________________
Is your laser a BAMF?

With great power comes a great need for safety.

I am SICK of spoon feeding noobs who just don't care to search the forum.

Lasers:
405nm Amazon Set
445nm BAMF Link
445nm 2358mW Peak The Bushwhacker by Dogs Best Friend
445nm Fantasy Link
532nm "200mW" DealExtreme Pointer
532nm Amazon Set
650nm Amazon Set
FastTech is the new DX. (Nope, prices have gone up, nevermind!)


Last edited by ryansoh3; 07-22-2012 at 10:08 PM.
ryansoh3 is offline   Reply With Quote
Old 07-22-2012, 10:18 PM #35
Blord's Avatar
Class 4 Laser
 
Join Date: Dec 2007
Location: Belgium
Posts: 5,368
Rep Power: 770
Blord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond repute
Blord Blord is offline
Class 4 Laser
Blord's Avatar
 
Join Date: Dec 2007
Location: Belgium
Posts: 5,368
Rep Power: 770
Blord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond reputeBlord has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

Just look at the position of one dot. It is vertical.

I made another picture of the dot in horizontal position. I have turned down the exposure because the dot is already very bright. You can see that the output is a lot more.
__________________
405nm 400mW S06J C6
445nm 3W Big Boy, 2.8W Dominator, 2.4W Steel Laser
450nm 240mW PL450 C6
473nm 100mW PGL-III-C-473
520nm 55mW Skylaser PL520
532nm 821mW Skylaser PL532, 133mW Jetlasers Ti-B
589nm 100mW PGL-III-C-589
635nm 70mW Sanyo SenTorch
638nm 175mW Ehgemus, 1W Rook
660nm 1216mW Skylaser PL660, 263mW LPC826 C6
685nm 33mW Fujitsu FLD6A2TK C6
780nm 150mW Dilda
808nm 640mW C6

I have copper 501B and Dominator lasers for sale !
Blord is offline   Reply With Quote
Old 07-22-2012, 10:22 PM #36
ryansoh3's Avatar
Class 3R Laser
 
Join Date: Feb 2012
Location: Pittsburgh
Posts: 1,282
Rep Power: 276
ryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond repute
ryansoh3 ryansoh3 is offline
Class 3R Laser
ryansoh3's Avatar
 
Join Date: Feb 2012
Location: Pittsburgh
Posts: 1,282
Rep Power: 276
ryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

Gotcha. Sorry, I didn't notice that at first glance.

This phenomenon is mind boggling though...

Cheers!
__________________
Is your laser a BAMF?

With great power comes a great need for safety.

I am SICK of spoon feeding noobs who just don't care to search the forum.

Lasers:
405nm Amazon Set
445nm BAMF Link
445nm 2358mW Peak The Bushwhacker by Dogs Best Friend
445nm Fantasy Link
532nm "200mW" DealExtreme Pointer
532nm Amazon Set
650nm Amazon Set
FastTech is the new DX. (Nope, prices have gone up, nevermind!)

ryansoh3 is offline   Reply With Quote
Old 07-22-2012, 10:28 PM #37
ryansoh3's Avatar
Class 3R Laser
 
Join Date: Feb 2012
Location: Pittsburgh
Posts: 1,282
Rep Power: 276
ryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond repute
ryansoh3 ryansoh3 is offline
Class 3R Laser
ryansoh3's Avatar
 
Join Date: Feb 2012
Location: Pittsburgh
Posts: 1,282
Rep Power: 276
ryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond reputeryansoh3 has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

Quote:
When light strikes the surface of a dielectric (non-conducting) material, a portion of the
incident light is reflected and the remainder is transmitted into the material. The fraction
of the incident light that is reflected depends on both the angle of incidence and the
polarization state of the incident light.
The functions that describe the reflection of light
polarized parallel and perpendicular to the plane of incidence are called the Fresnel
Equations. (The plane of incidence is the plane that contains the incident and reflected
rays and the normal to the surface.) Figure 1 shows a graph of the Fresnel equations.
Notice that perpendicular () polarization is almost always reflected more strongly than
the parallel (||) state. The exception occurs at normal incidence and at near 90 o
incidence, where they are both reflected equally. Figure 1 also shows that for one angle
of incidence, called Brewster's Angle, none of the parallel polarization is reflected.
Sorry for the block of text, but I think this is it. I'm guessing that the polarization of the laser beam directly affects the percentage of the light reflected via the glass.

The document is here:

http://uotechnology.edu.iq/dep-laser...9s%20Angle.pdf

Cheers!
__________________
Is your laser a BAMF?

With great power comes a great need for safety.

I am SICK of spoon feeding noobs who just don't care to search the forum.

Lasers:
405nm Amazon Set
445nm BAMF Link
445nm 2358mW Peak The Bushwhacker by Dogs Best Friend
445nm Fantasy Link
532nm "200mW" DealExtreme Pointer
532nm Amazon Set
650nm Amazon Set
FastTech is the new DX. (Nope, prices have gone up, nevermind!)


Last edited by ryansoh3; 07-22-2012 at 10:34 PM.
ryansoh3 is offline   Reply With Quote
Old 07-22-2012, 11:49 PM #38
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,141
Rep Power: 9321
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: 9,141
Rep Power: 9321
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: Extend the LPM range with a filter.

I just tried it and I got the same problem. Not as pronounced (18mW vs 57mW), but definitely making it useless for your standard pointer. I know for a fact many systems use this method, but the glass, beam, and photo-diode never move with respect to each other.

I've personally used the diffraction grating method in the past though. I've just tried it again at various angles and rotations, and it makes about zero difference. Try that one. I like these, if you don't already have one.
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 07-23-2012, 12:26 PM #39
lasersbee's Avatar
Class 4 Laser
 
Join Date: Sep 2008
Location: Quebec, Canada
Posts: 15,692
Rep Power: 38652
lasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond repute
lasersbee lasersbee is online now
Class 4 Laser
lasersbee's Avatar
 
Join Date: Sep 2008
Location: Quebec, Canada
Posts: 15,692
Rep Power: 38652
lasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond reputelasersbee has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

How do they hold up to a 2Watt beam...??
At what power would the plastic diffraction gratings
start to damage ??


Jerry

You can contact us at any time on our Website: J.BAUER Electronics
__________________

J.BAUER Electronics Home Page

LaserBee Laser Power Meter Products meet your needs
at affordable Prices:
See them all here on LPF

LaserBee Power Meter products ALWAYS in Stock
and ready to ship

Also available on eBay:Check availability here..

Subsidary: Pharma Electronic Solutions


This banner is available to and can be copied/used FREE by any LaserBee owner
lasersbee is online now   Reply With Quote
Old 07-23-2012, 02:35 PM #40
Cyparagon's Avatar
Class 4 Laser
 
Join Date: Sep 2007
Location: Wisconsin
Posts: 9,141
Rep Power: 9321
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: 9,141
Rep Power: 9321
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: Extend the LPM range with a filter.

Quote:
Originally Posted by lasersbee View Post
How do they hold up to a 2Watt beam...??


Quote:
Originally Posted by Cyparagon View Post
I've had cheap plastic gratings (dirty, even) in the path of a 4W beam and they're just fine.
__________________
A problem well stated is a problem half solved.
Cyparagon is online now   Reply With Quote
Old 08-14-2012, 01:25 AM #41
Class 2M Laser
 
Join Date: May 2009
Posts: 955
Rep Power: 1542
LSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond repute
LSRFAQ LSRFAQ is offline
Class 2M Laser
 
Join Date: May 2009
Posts: 955
Rep Power: 1542
LSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

Unless you compensate for it, the law of Malus (polarization vs angle) will come back to bite you.

Schott NG-5
Schott BG-5
Schott BG-10

Steve
LSRFAQ is offline   Reply With Quote
Old 08-14-2012, 01:30 AM #42
Class 2M Laser
 
Join Date: May 2009
Posts: 955
Rep Power: 1542
LSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond repute
LSRFAQ LSRFAQ is offline
Class 2M Laser
 
Join Date: May 2009
Posts: 955
Rep Power: 1542
LSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond reputeLSRFAQ has a reputation beyond repute
Default Re: Extend the LPM range with a filter.

Unless you compensate for it, the law of Malus (polarization vs angle) will come back to bite you.

Schott NG-5 is a typical glass used as a flat attenuator.

The Schott data sheet shows the normalized adsorption. You'll have to pick a thickness corresponding to the attenuation you really need.

Its not truely flat on its curve, but close.

This is one of the reasons why the lasercheck has a EEPROM.

Steve
LSRFAQ 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 05:16 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