LASER
,LASER is an acronym for light amplification by
stimulated emission of radiation.
It is device to produce a strong ,
monochromatic, collimated and coherent
beam of light and emits light (
electromagnetic radiation) through a process
called stimulated emission , first predicted by
EINSTEIN in 1916.
The first working laser was demonstrated on
16 May 1960 by Theodore Maiman at
Hughes Research Laboratories using Ruby as
active medium
,Explain the terms absorption, spontaneous
emission and stimulated emission of
radiations. Also obtain the relation between the
transition probabilities of spontaneous emission
and stimulated emission
( Einstein’s Coefficients)
, ABSORPTION OF RADIATION
In a material, atoms are in ground state with
energy E1. When a photon of energy E2 − E1 = hν
is incident on the material, the atoms in the
ground state absorb energy and jumps over to
excited state E2. This process is called induced
absorption as shown in fig.
ATOM + PHOTON → ATOM* (EXCITED)
,LASER is an acronym for light amplification by
stimulated emission of radiation.
It is device to produce a strong ,
monochromatic, collimated and coherent
beam of light and emits light (
electromagnetic radiation) through a process
called stimulated emission , first predicted by
EINSTEIN in 1916.
The first working laser was demonstrated on
16 May 1960 by Theodore Maiman at
Hughes Research Laboratories using Ruby as
active medium
,Explain the terms absorption, spontaneous
emission and stimulated emission of
radiations. Also obtain the relation between the
transition probabilities of spontaneous emission
and stimulated emission
( Einstein’s Coefficients)
, ABSORPTION OF RADIATION
In a material, atoms are in ground state with
energy E1. When a photon of energy E2 − E1 = hν
is incident on the material, the atoms in the
ground state absorb energy and jumps over to
excited state E2. This process is called induced
absorption as shown in fig.
ATOM + PHOTON → ATOM* (EXCITED)
