White Light Lasers:

    White light lasers produce one single beam.  This beam then passes through a prism.  Once the light passes through the prism, it is broken into several beams with distinct colors.  KAL uses this type of laser because it is more efficient than many others.  Instead of only emitting a few colors, we provide our viewers with a wide variety of colors.1 

            Yag Lasers

    Yag lasers are solid state lasers.  These lasers use yttrium aluminum garnet as the lasing medium.  The color that is emitted through this laser is a bright green color.  There is normally a flash lamp that is used to help excite the electrons in this laser.1 

 

http://www.technology.niagarac.on.ca/courses/tech238g/Lasers.html

This is an example of the first set of lasers.  It mostly only referred to as a historical laser.  It uses a ruby coil, but the main ideas from this laser is what is now used modern day lasers. The HeNE laser is based off of this laser.  energy is used to excite the electrons to move from the ground state to a higher valance shell. Then the photons are "bounced" off of a mirror that is coated to make sure it reflects the photons instead of absorbing them.  Once the photons are reflected, the excited atoms emit a light wave, which is coherent.  These parallel waves are then projected out of the laser device, and used for the laser show. 

More Types of Lasers2

Name Lasing material Power range

pulsed/cw

 Beam properties, Wavelength Applications
YAG Nd3+-ions in host material YAG

4-level

 cw 0.2mW -10W

Q-switched 1mJ-1J per pulse

 Good beam quality, 1064nm (IR) also SHG (see ch4) 532nm Distance measuring, chemical large-distance analysis, pointer for electronic vision

SHG also pointing for human vision
Erbium

Holmium

 Er3+ and Ho3+-ions in different host materials (YAG, YLF, glass)

3-level systems

 Q-switched 1mJ-100mJ Several more or less eye-safe wavelengths between 1.4µm and 1.9µm Not yet fully established commercially, but will replace YAG in many applications where human eyes can be injured (and this is not the purpose)
Titanium-sapphire Ti-ions with sapphire (Al2O3) as host material Pumped by laser only; you need another laser to pump this one. Possible to set between 650nm and 1050nm (approximately)) All applications needing laser with extremely short pulses (.01ps)
Ruby Cr3+-doped sapphire

3-level system

 Pelsed1mJ to 10J during some ten nanoseconds 694nm, bad profile of beam, unstable. Today mostly historical interest. First laser ever built.

 Gas Lasers2
Name Lasing material Power range

pulsed/cw

 Beam properties, Wavelength Applications
Helium-Neon Gas mixture. Helium Absorbs energy from the current and pass it on to Neon. Only cw 0.2mW-20mW Very good, often more than 99%TEM00

633nm

 All-round where the power isn't the issue. Distance measuring, pointer, angular measurements, building and construction, teaching.
Argon Ionized Argon gas Cw from 10mW to 25W

Pulsed (often mode locked, but unusual). Top power in the kW-range

 Good, often multi-line several (to the eye discernable) wavelengths lasing at the same time.

UV to 514nm

 Measuring greater distances, directional aid (e.g. at airports), holography, entertainment use, measurement of gaseous and liquid flow
Helium-Cadmium As HeNe with Cadmium replacing Ne. 1mW to 10mW

only cw

 Very good. However, the laser costs 5-10 times as much as HeNe. Same as HeNe, but in applications needing shorter wavelength.
Carbon dioxide Gaseous CO2 from 10mW up to 25kW (!!!!) cw

Also pulsed

 Poor. 10.6µm; far out in the IR-part of the spectrum. Need to use special optics (often germanium-based) Due to high efficiency often for industrial purposes.

Destructive at close range?

 

            1*- How lasers work. Available Online.    

               <http://www.technology.niagarac.on.ca/courses/tech238g/Lasers.html >

                    6 April 2005.

            2*- Different Types of Lasers. Available Online.

                <www.optics.kth.se/book/ch3/page3/huvudsid3.htm> 5 April 2005.

    **This page is not that of a real company, but is for a chemistry assignment for general cehmistry 140 at Monmouth College. **

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