Lasers

Ruby laser is a

• solid laser

• liquid laser

• gaseous laser

• molecular laser

Active medium in Argon ion laser

• Helium

• Argon ions

• Chromium ions

• Argon gas

In semiconductor laser population inversion is acheived by

• Electrical discharge

• Direct conversion

• optical pumping

• In elastic collision of atoms

The wavelenth emitted by semiconductor laser is ---- A

• 6943

• 6328

• 8400

• 8000

In He-Ne laser gasses are taken in the ratio

• 1:10

• 10:1

• 1:4:5

• 4:5

Gaseous laser is a

• Three level laser

• two level laser

• Four level laser

• Five level laser

Active center in Nd-Yag laser

• Neodymium ions

• yttrium ion

• chromium ions

• aluminium ions

The Active center in He-Ne laser

• helium

• neon

• helium and Neon

• both

The active center in CO2 laser

• carbo

• helium

• nitrogen

• Cabondioxide

The pumping method used in Ruby laser is

• direct conversion

• Electricel discherge

• optical pumping

• chemical reaction