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Chemical Laser Spectroscopy

mod101

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I was wondering if anyone here had anything to do with Laser Spectroscopy. As an undergrad taking organic chemistry this year I am being introduced to the principles of laser spectroscopy and research dealing with this type of spectroscopy.

It actually sounds like some pretty interesting stuff. We had a proffesor visit here and share his research on the use of IR and other types of laser spectroscopy to investigate the inter/intramolecular forces that affect molecules.

Not only is it putting together the puzzles of chemistry but i also get to shoot giant lasers at molecules
:lasergun: :evil:

anyone else play with spectroscopy?
 





Arayan

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I use a laser spectroscope and also an equipment for Surface Plasmon Resonance :)
 

DavidN

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HI, Im new to the board, but currently involved with laser spectroscopy as well for hydrocarbons. Nice to see ya on the board.
 
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I've used fiber fed usb interfaces, and diffraction index experiments, but nothing with CCDs.
 

qqqq

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I used to work in an ultrafast lab studying condensed-phase dynamics. We did a lot of work with fs & ps Ti:Sapphire, some YAG-pumped dye lasers. There are a lot of crazy things you can study with the appropriate gear.

Q
 
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X-RF(X-ray fluorescence) for me. A good way to determine composition of some semiconductor materials. :)
 

LSRFAQ

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3 years of Raman/Brillioun with ion lasers, at resolution measured in 10s of gigahertz. The Lasers were frequency locked to a iodine hyperfine transition to stabilize them. I built the locking systems and maintained the lasers.

Typical exposures would be a protein sample swept in temperature and pressure. Typically from liquid nitrogen to boiling during a 72 hour exposure. Proteins change structure with temperature and pressure in extreme ways.

Ruby changes the wavelength of its 694 nm emission with applied pressure, so we'd have a chunk of ruby in the exposure cell with the sample when we pressurized them between two optically polished anvils made of diamond or monazite.

Readouts were liquid nitrogen cooled, photon counting linear ccds hooked to 3 meter spectrographs or Sander-Cook interferometers.

The guys next door had femtosecond lasers tunable from 650 nm to 10 microns. Ended up helping them out too.

Raman, in this case, is wavelength shifts in the scattered light from interacting with electron orbitals at bonds in molecules. Each type of bond has a characteristic shift that shows up.

Brillioun is slight changes in the scattered light's wavelength from variations of the speed of thermally induced "sound" waves that are in every material above absolute zero. Brillioun shifts are very tiny.

Steve
 
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3 years of Raman/Brillioun with ion lasers, at resolution measured in 10s of gigahertz. The Lasers were frequency locked to a iodine hyperfine transition to stabilize them. I built the locking systems and maintained the lasers.

Typical exposures would be a protein sample swept in temperature and pressure. Typically from liquid nitrogen to boiling during a 72 hour exposure. Proteins change structure with temperature and pressure in extreme ways.

Ruby changes the wavelength of its 694 nm emission with applied pressure, so we'd have a chunk of ruby in the exposure cell with the sample when we pressurized them between two optically polished anvils made of diamond or monazite.

Readouts were liquid nitrogen cooled, photon counting linear ccds hooked to 3 meter spectrographs or Sander-Cook interferometers.

The guys next door had femtosecond lasers tunable from 650 nm to 10 microns. Ended up helping them out too.

Raman, in this case, is wavelength shifts in the scattered light from interacting with electron orbitals at bonds in molecules. Each type of bond has a characteristic shift that shows up.

Brillioun is slight changes in the scattered light's wavelength from variations of the speed of thermally induced "sound" waves that are in every material above absolute zero. Brillioun shifts are very tiny.

Steve


Yeah! What is this place you worked at??? I have never heard of lasers being used like this before! It is inspiring hearing about lasers being used many ways. :)
Now I want to hear more about this. How would one get to a career path of this kind of research and work field? :thanks: a lot for sharing everyone!!!!!! :beer:
 

LSRFAQ

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Yeah! What is this place you worked at??? I have never heard of lasers being used like this before! It is inspiring hearing about lasers being used many ways. :)
Now I want to hear more about this. How would one get to a career path of this kind of research and work field? :thanks: a lot for sharing everyone!!!!!! :beer:

I worked in a SIMPLE laser spectroscopy lab that has been disbanded at the University of Akron. Most of that gear is off the shelf, and its what you do with it and how you cross connect it that counts. I did not mention the laser spectroscopy combined with atomic force microscopy. Servo systems tracked the Raman illumination spot onto the AFM tip.

What I describe is not all that complex. This guy does complex:

Theodor W. Hänsch - Wikipedia, the free encyclopedia

Homepage Prof. T.W. Haensch

He does things with tunable lasers that will blow your mind.

You need to start with a Bachelors in Electrical or Chemical Engineering or a undergrad in Physics.
Your then looking at graduate school, either 3 or 5 years. Some government agency usually pays for the graduate school.

If your very lucky, you can just be a technician, but those slots are rare, and you have to be in the right place at the right time to get the slot. I'm a technician. The technicians have to learn what is going on to higher levels then the students do, its not easy to work in a world class lab.
Technicians in these cases have a two or four year degree in electronics and often need machine shop skills as well.

University lab techs are rare, usually only a few per campus and then only on big campuses.

Getting a tech slot working in a general purpose university lab is pretty much a ACT OF GOD. Even then, HE really has to like you. Even HE has to pull some strings to get you the position.
Odds are I will never get to work on something that "complex" and "cool" again.

The real way to get access to laser gear like that is to be a graduate student. That means two more years of classes and a year or three years of research, once you are done with your undergraduate degree. You have to get really good high school and college grades for the scholarships. Your alternative is be employed by the military or a very large company since no one could afford tuition at the Masters/ PhD level in science. Companies like their mid level people to complete a Masters. You have to be competitive.

You could get a EE or ME or Math Degree and then go work at a Laser Company such as Coherent or Spectra Physics, but I think you'll find those slots are very rare, as well.


If you want that, STUDY MATH. Eat, Drink, and LIVE MATH. Calc I, Calc II, Geometry, High order equation solving. The chemistry and physics classes are easy, its the math you need. You also need strong programing skills in the C or C++ languages and in assembly language.

When you get the job, you find out you use less then .5% of all that math you spend years learning.

I should mention, that it might be 2-4 years of college before you even get to do more then tour a lab. That is changing, as more and more labs get funding to have the odd undergrad student help out on projects.

Another alternative if you wish to spend your life playing with cool toys is to teach high school science. Your allowed to have toys, but you must build your own in most cases.

What I worked is now obsolete. I bought some pieces of the gear at the university disposal office.

Steve
 
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