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 > Science & Lasers



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



Reply
 
LinkBack Thread Tools Display Modes
Old 06-03-2008, 05:00 PM #1
Class 2M Laser
 
Join Date: Sep 2007
Posts: 526
Rep Power: 12
disma is on a distinguished road
disma disma is offline
Class 2M Laser
 
Join Date: Sep 2007
Posts: 526
Rep Power: 12
disma is on a distinguished road
Default interferometry

Has anyone played with building an interferometer with thier laser? :-?

Max


disma is offline   Reply With Quote







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







Old 06-04-2008, 01:16 AM #2
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: interferometry

never even heard what an interferometer is (i can imagine what it is but never seen one)
nikokapo is offline   Reply With Quote
Old 06-04-2008, 02:10 AM #3
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
climbak climbak is offline
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
Default Re: interferometry

i work with interferometers quite a bit with lasers. I have built several Michelsons, a Fabry-Perot, I've used a shear plate interf. and know how to set up a Lloyd's mirror and Mach-Zenders. An intereferometer is an instrument that uses intereference from light that has been split into two seperate paths and rejoined later on to study something. That something can be a lot of things. Currently I'm using Michelsons to determine the coherence length and visibility of the blu-rays to see if they are usable to write the holograms the company I work for uses. I'm headed out the door, but if you want to know anything else let me know and I'll do my best to answer any questions.
climbak is offline   Reply With Quote
Old 06-04-2008, 03:50 AM #4
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: interferometry

ok, i didnt understand the first sentence.

but it does sound very interesting, i'd like to know more about this.


are you saying in reality all beams split somewhere and then join again?
Attached Thumbnails
interferometry-dibujo_001.jpg  
nikokapo is offline   Reply With Quote
Old 06-04-2008, 05:41 AM #5
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
climbak climbak is offline
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
Default Re: interferometry

wow, yeah I just read that first sentence. It's pretty much terrible haha. Beams do not split like that. An interferometer is what splits the beams apart. When the beams are split up they take different paths. If the paths lengths are different the light may no longer be in phase. This can cause interference. If the path length differenceis an integer multiples of the wavelength then the two beams will interfere constructively and the intensity will be high. If the path length difference is a half integer multiple then there will be destructive interference and the intensity will be low. For path length differences in between these values the intensity will be somewhere in between. We can use this fact to study various things. I use it to determine coherence length which is related to the spread in wavelength the laser emits. My professor uses interferometers to study the wave nature of atoms in order to discover tings about the atoms. There are a lot of uses for interferometers, most of which I am clueless about. Here is a picture of a Michelson interferometer just as an example. This particular set up has a gas cell in the path of one beam so that the index of refraction can be determined for that gas.

EDIT: by the way, that observer picture is not actually meant to be an eye. that would not be a good idea. its usually a screen or detector of some sort.
Attached Thumbnails
interferometry-mminterf.jpg  
climbak is offline   Reply With Quote
Old 06-04-2008, 05:02 PM #6
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: interferometry

cool, thx for the explanation.


is the observer/dectector who determines the integer's value? or do you have to calculate it somehow with what you get inside the gas cell?
nikokapo is offline   Reply With Quote
Old 06-04-2008, 06:26 PM #7
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
climbak climbak is offline
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
Default Re: interferometry

For that particular experiment you change the pressure within the cell and count how many fringes go by. There is a formula that can be derived from a few other principles that basically relates the change in pressure and the change in the fringes that go by to the index of refraction. The fringes are the light and dark regions in the interference pattern.
climbak is offline   Reply With Quote
Old 06-04-2008, 07:49 PM #8
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: interferometry

Thank you so much!!, i'll read on wikipedia later, i have to go to english classes.
nikokapo is offline   Reply With Quote
Old 06-04-2008, 08:48 PM #9
Class 2M Laser
 
Join Date: Sep 2007
Posts: 526
Rep Power: 12
disma is on a distinguished road
disma disma is offline
Class 2M Laser
 
Join Date: Sep 2007
Posts: 526
Rep Power: 12
disma is on a distinguished road
Default Re: interferometry

Thanks for the awesome explanation! I have wanted to try to make an interferometer for a while now. I just need a suitable beam splitter. Maybe one of these cd drives will have one I can use.

Max
disma is offline   Reply With Quote
Old 06-04-2008, 10:08 PM #10
Switch's Avatar
Class 3B Laser
 
Join Date: Dec 2007
Posts: 3,327
Rep Power: 166
Switch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond repute
Switch Switch is offline
Class 3B Laser
Switch's Avatar
 
Join Date: Dec 2007
Posts: 3,327
Rep Power: 166
Switch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond reputeSwitch has a reputation beyond repute
Default Re: interferometry

The brewster window I used as a dichro for combining works pretty well for green lasers at 45 degrees. :-/
Switch is offline   Reply With Quote
Old 06-05-2008, 03:14 AM #11
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
climbak climbak is offline
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
Default Re: interferometry

microscope slides work great. i use them almost exclusively.
climbak is offline   Reply With Quote
Old 06-05-2008, 03:23 AM #12
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: interferometry

Quote:
Originally Posted by climbak
microscope slides work great. i use them almost exclusively.
WHAT?

you use microscope slides as dichros?? or to split the beams?
nikokapo is offline   Reply With Quote
Old 06-05-2008, 04:07 AM #13
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
climbak climbak is offline
Class 2 Laser
 
Join Date: Apr 2008
Location: Tucson, AZ
Posts: 373
Rep Power: 14
climbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the roughclimbak is a jewel in the rough
Default Re: interferometry

beam spiltters
climbak is offline   Reply With Quote
Old 06-05-2008, 06:24 PM #14
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: interferometry

Quote:
Originally Posted by climbak
beam spiltters

Oh, ok. I'll try that sometime
nikokapo is offline   Reply With Quote
Old 06-07-2008, 06:17 AM #15
pullbangdead's Avatar
Class 3R Laser
 
Join Date: Aug 2007
Posts: 2,045
Rep Power: 238
pullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond repute
pullbangdead pullbangdead is offline
Class 3R Laser
pullbangdead's Avatar
 
Join Date: Aug 2007
Posts: 2,045
Rep Power: 238
pullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond reputepullbangdead has a reputation beyond repute
Default Re: interferometry

Also, interferometry can be used to measure the thickness of thin films, without even doing anything else with the light. Doesn't even have to be coherent. Light hits the surface at a non-perpendicular angle: some is reflected at the air-film interface, and some goes through. Then, some light is reflected at the film-substrate interface. Light from both paths then hits the detector, but since the paths were different lengths, the light from the different paths will be out of phase, causing interference. With some more complication and a little math, you can calculate the difference in path lengths, and therefore the film thickness.

This is also exactly what you do with x-ray diffraction, kind of. Except it's x-rays, and the x-rays reflect off of different planes of atoms in the material, giving you the interatomic (or "d&quot spacing in a material. Bragg's law is basically derived straight from the picture I described above.
pullbangdead is offline   Reply With Quote
Old 06-07-2008, 06:22 PM #16
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
nikokapo nikokapo is offline
Cereal Eater
 
Join Date: Dec 2007
Location: Argentina
Posts: 6,333
Rep Power: 331
nikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond reputenikokapo has a reputation beyond repute
Send a message via MSN to nikokapo
Default Re: interferometry

Quote:
Originally Posted by pullbangdead
Also, interferometry can be used to measure the thickness of thin films, without even doing anything else with the light. *Doesn't even have to be coherent. *Light hits the surface at a non-perpendicular angle: some is reflected at the air-film interface, and some goes through. *Then, some light is reflected at the film-substrate interface. *Light from both paths then hits the detector, but since the paths were different lengths, the light from the different paths will be out of phase, causing interference. *With some more complication and a little math, you can calculate the difference in path lengths, and therefore the film thickness.

This is also exactly what you do with x-ray diffraction, kind of. *Except it's x-rays, and the x-rays reflect off of different planes of atoms in the material, giving you the interatomic (or "d&quot spacing in a material. *Bragg's law is basically derived straight from the picture I described above.
So they use x-rays to determine the difference/distance from something to something else?
nikokapo 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 02:20 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