Atomic Gas Lasers: Principles & Applications

Atomic gas lasers
Plasma, P~30-100 Torr
diameter of 0.5-10 mm
Ion fraction one part per
104or 105in Ar ion laser
it is 1%
Acts as an
electron gun ion
accelerated to
exctract electron
by collision with
the electrode.
Rarely, The
amplifying
medium
S. Hooker, C. Webb, Laser physics, Oxford master series in atomic
optical and laser physics, Oxford university press (2014)

Plasma constraints
S. Hooker, C. Webb, Laser physics, Oxford master series in atomic
optical and laser physics, Oxford university press (2014)
E*Id
Electron and ion
densities
Electron
temperature
E= axial electric field
Electron velocity drift
Depends on E/N

Davis, C. C. Lasers and electro-optics: fundamentals and engineering; Cambridge University Press, 2014
He-Ne lasers ~200 000 lasers sold each year
price of production +/- 100 euros

or
Energy transfer by collisions
The same order as kT in a discharge
Long lived states
No change of parity with the
ground state or change of
electronic spin multiplicity

Low pressure to
maintain the
discharge stability
S. Hooker, C. Webb, Laser physics, Oxford master series in atomic
optical and laser physics, Oxford university press (2014)
At higher
pressure the
geometry of the
discharge need
to be changed.