Ruby laser construction and working.

1. Ms. T. Manonmani
Asst. professor of
physics

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.

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.

10.  Monochromaticity
 Directionality
 Spatial Coherence
 Temporal Coherence and Brightness.