Laser Experiments at Home - Helium Neon 1mW

In summary, the conversation covers various experiments that can be conducted at home with a used helium neon 1 mW laser. These experiments include creating a diffraction pattern using a small slit or wire, burning objects with precise alignment, and using a crystal to double the laser's frequency. The topic of holography is also discussed, with suggestions for making holograms at home using a digital camera or white light as a reference beam. Other ideas for experiments include measuring the laser's wavelength with a ruler, studying polarization, and creating white light viewable holograms. The conversation also touches upon the challenges and equipment needed for successful holography experiments.
  • #1
scupydog
101
0
Hi all, I've just got hold of a used helium neon 1 mW laser (spectra physics model 155) and would like to some experiments at home, does anyone know any good examples Thx
 
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  • #2
You could get a diffraction pattern of a small slit or wire ( human hair works). Experiment with double slits, and many more.
You could try to burn something, but you need a good lens and exact alignment.

Its usual operation wavelength is 632.8 nm. Red part of the spectrum. So no chemical reactions that i can think of will occur (except very photosensitive materials).

With a crystal of potassium titanyl phosphate and complicated assembly you could double it's frequency ( 316.4 nm ).
 
  • #3
holograms?
 
  • #4
Lok said:
You could get a diffraction pattern of a small slit or wire ( human hair works). Experiment with double slits, and many more.
You could try to burn something, but you need a good lens and exact alignment.

Its usual operation wavelength is 632.8 nm. Red part of the spectrum. So no chemical reactions that i can think of will occur (except very photosensitive materials).

With a crystal of potassium titanyl phosphate and complicated assembly you could double it's frequency ( 316.4 nm ).
thx lok i'll try these (1st two)

mgb_phys said:
holograms?

hi I've looked at holography, would it be possible to replace the photographic paper with a digital camera??
 
  • #5
scupydog said:
hi I've looked at holography, would it be possible to replace the photographic paper with a digital camera??
Not as such - you have no way of reconstructing the wavefront (ie viewing the hologram)
These guys have done something similair with a digital camera http://www.me.jhu.edu/lefd/shc/LPho...Laser Pointer and Consumer Digital Camera.pdf although strictly it's more speckle interferometry than a hologram
 
  • #6
Look for http://en.wikipedia.org/wiki/Arago_spot" [Broken].
 
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  • #7
You can make a simple Michelson-Morley interferometer and play around with wave interference.
 
  • #8
A couple of quickies:

Use a CD as a diffraction grating. From the diffracted beam angles, determine the spacing of tracks on the CD.

Use a pin to make a small circular hole in a sheet of paper. Look at the diffraction patern.
 
  • #9
All good suggestions above. One of my favorites was measuring the wavelength of the laser with a ruler... Really... Generally need a steel ruler with lines that are etched into it to form your "grating".

Lay the ruler down flat and bring the beam in at an extremely shallow angle and based on the angles present and the space in between the diffraction orders you can calculate the wavelength pretty accurately. Here is a good link for the lab.

http://www.mtholyoke.edu/courses/mpeterso/phys204/labs/Diffraction.htm
 
  • #10
It's been a long time since I did it in school but i do remember doing a holography lab that uses the white light of the room as the reference? beam to complete the hologram so it can be viewed at any time. If not you do need the laser to actually view the hologram as well if it is used for both the object and reference beams.

I'll see if i still have that stuff laying around anywhere and upload it. Note that it also takes a very stable optics table, a power meter so you can calculate the exposure time a decent amount of mirrors/mounts and the ability to develop the holographic plates... but it sure is fun!
 
  • #11
Keep thinking of things:P

If you're interested in polarization it's easy enough to try with a couple of old sunglasses. Try to determine what the polarization of the laser is. Can you get the beam to cancel with one polarizer or does it take two? If you can manage to get a quarter-wave plate what happens when you put it inbetween the two polarizers that do cancel the beam?

Also how does the polarization of a beam chance with reflection... take some data points and plot it out vs output power... :) Very cool stuff. Yay for photons.
 
  • #12
I want a multi line argon... :(
 
  • #13
Lambduh said:
uses the white light of the room as the reference? beam to complete the hologram so it can be viewed at any time. If not you do need the laser to actually view the hologram as well if it is used for both the object and reference beams.

I'll see if i still have that stuff laying around anywhere and upload it. Note that it also takes a very stable optics table, a power meter so you can calculate the exposure time a decent amount of mirrors/mounts and the ability to develop the holographic plates...

You can make white light viewable holograms - they just have a restricted viewing angle.
If you don't have an optical table, mirrors on sticks in a sandbox work well, so does glueing everything to a paving slab and sitting it on a bike inner tube.

You can o hologram with film if you clamp it to a flat plate but it's a bit hit and miss, any fraction of a wavelenght movement ruins it.
 
  • #14
wow thanks for all your replies, the holography looks good especially when you read how it works...thats why i love physics... brilliant and thanks too Lambduh some good ideas there

dave.
 
  • #15
Integral said:
Look for http://en.wikipedia.org/wiki/Arago_spot" [Broken].

hi Integral I've looked for the arago spot but noluck yet, have you any ideas on size of circular object or distance to shadow/object/laser thanks
dave.
 
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What is a Helium Neon laser?

A Helium Neon laser is a type of gas laser that emits a red light with a wavelength of 632.8 nanometers. It consists of a mixture of helium and neon gases enclosed in a glass tube, along with mirrors at each end to reflect and amplify the light.

Can I conduct laser experiments at home?

Yes, you can conduct laser experiments at home as long as you take proper safety precautions and follow instructions carefully. Laser pointers, such as the 1mW Helium Neon laser, are relatively safe to use for home experiments.

What types of experiments can I do with a 1mW Helium Neon laser?

Some possible experiments you can do with a 1mW Helium Neon laser include measuring the speed of light, creating diffraction patterns, and demonstrating the properties of laser light, such as coherence and monochromaticity.

Do I need any special equipment for laser experiments at home?

In addition to the Helium Neon laser, you may also need some basic equipment such as mirrors, diffraction gratings, and lenses. These can be purchased from science supply stores or online.

Are there any safety precautions I should take when conducting laser experiments at home?

Yes, it is important to always wear proper eye protection when working with lasers. Also, be sure to read and follow all safety instructions that come with your laser, and never point the laser at anyone's eyes or reflective surfaces.

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