2. INTRODUCTION
A ruby laser is a solid-state laser.
Ruby laser is the first successful laser
developed by Maiman in 1960.
3. Ruby laser – consists – cylindrical rod-
optically flat and accurately parallel.
One end – fully silvered – other is partially
silvered.
Ruby rod – surrounded by a glass tube.
Glass tube – surrounded by a helical xenon
flash tube – acts – optical pumping system.
4.
5.
6. Ruby rod- aluminium oxide (Al2O3) – doped with
0.05%chromium oxide Cr2O3.
Aluminium atoms in the crystal lattice – replaced
by Cr3+
Cr ions exited from level E1 to E2 - by
absorption of light of wavelength 550nm – from
xenon flash tube.
Excited ions – nonradiative transitions with a
transfer of energy - level E2 – meta stable state
– lifetime – 3×10-3 s.
7. Population of E2 level – greater than level E1.
Population inversion is achived.
Some photons – produced by sponteneous
transition from E2 to E1 - wavelength 694.3nm.
Ruby rod – acts – reflecting mirror.
Photons – not moving parallel to ruby rod – but
reflected back and forth.
These stimulate the emission of similar other
photons.
8. Chain reaction – develops – beam of
photons – moving parallel to rod –
monochromatic and coherent.
All chromium ions – metastable level –
returned – ground state – laser action stop.
Send – one more flash of pumping radiation
– through the rod.
Ruby laser – operates – only in pulses.
