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Chapter I Brief Introduction...
Figure: 1.7 Schematic representation of Optical Parametric Oscillator.
This is a three photon process in which one photon with energy h is
absorbed and two photons with energies h1 and h2 are emitted.
Differential-Frequency Generation (DFG)
From the equation (1.7) the difference of frequency term is obtained
which is ω1−ω2=ω3 (or in form of wavelength 1/λ1-1/λ2=1/λ3)
It combines two high energy photons into a low energy photon. This is shown
schematically in figure (1.8).
Figure: 1.8 Schematic representation of difference frequency generation.
Linear Electro-optic Effect or Pockels Effect
The Pockels effect is a linear change in the refractive index (or the
optical susceptibility) of a medium in the presence of an external electric field.
Here a DC field is applied to a medium through which an optical wave
propagates. The change in the polarization due to the presence of these two
interacting field components effectively alters the refractive index of the
medium [15].
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