Ruby laser

Ruby laser construction and working.

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

2. Ruby Laser INTRODUCTION A ruby laser is a solid-state laser. Ruby laser is the first successful laser developed by Maiman in 1960 .

3. CONSTRUCTION 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. WORKING Ruby rod- aluminium oxide (Al 2 O 3 ) – doped with 0.05%chromium oxide Cr 2 O 3. Aluminium atoms in the crystal lattice – replaced by Cr 3+ Cr ions exited from level E 1 to E 2 - by absorption of light of wavelength 550nm – from xenon flash tube. Excited ions – nonradiative transitions with a transfer of energy - level E 2 – meta stable state – lifetime – 3× 10 -3 s.

5. Population of E 2 level – greater than level E 1. Population inversion is achived . Some photons – produced by sponteneous transition from E 2 to E 1 - 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 .

6. 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.

7. Energy level diagram

8. PROPERTIES OF LASER BEAM Monochromaticity Directionality Spatial Coherence Temporal Coherence and Brightness .

9. THANK YOU