Nn = No e-∆E/kT Harry Kroto 2004

Pumped into population inversion condition by source of IR radiation Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

Harry Kroto 2004

The maser may switch of after say 3 days so the dimension of the cloud can be estimated from the time for the light wave to pass through the cloud as about 1/100th of a ly and leave the molecules in their lower states. It will take several days to pump up to population inversion again and switch on again Harry Kroto 2004

So what we need is population inversion Nn > Nm So what we need is population inversion Harry Kroto 2004

http://www. scienceclarified http://www.scienceclarified.com/scitech/Lasers/The-Development-of-Lasers.html

– + – + The voltage will follow a hyperbolic function – but we need to know the field E(q) = dV/dq

y X V = Vo + a x y

y X V = Vo + a x y dV/dx = a y dV/dy = a x

y X V = Vo + a x y dV/dx = a y dV/dy = a x dV/dr = a(x2 + y2)½

V = Vo + a x y dV/dx = a y dV/dy = a x dV/dr = a(x2 + y2)½ |E| = |a| r

So the field E is increases radially as r X V = Vo + a x y dV/dx = a y dV/dy = a x dV/dr = a(x2 + y2)½ E = a r So the field E is increases radially as r

Focussed n H = – E. μ m Defocussed r →

Defocussed m n Focussed m

y X n Population Inversion m