1.2 Spatial Coherence of Rhodamine 6G Laser Radiation …
19
Fig. 1.8 Study of spatial coherence function homogeneity. Reprinted from [54] with permission
where I(r 0 , r j ) is the intensity of the image in the point r 0 during the reconstruction
of a hologram along the point r j ; I(r j , r 0 ) is the intensity of the image in the point r j
during the reconstruction of a hologram along the point r 0 ; I(r j , r j ) is the intensity of
the image in the point r j during the reconstruction of a hologram along the point r j ;
index 0 is the laser end point index, as relative to which spatial coherence function
was determined, j = 1, 2, 3 is the running index of the laser end point.
As it can be seen from Fig. 1.8, laser spatial coherence function considerably
depends on the distance between laser edge points and practically does not depend
on the position of supporting point r j .
Thus, spatial coherence function is almost homogeneous function. It proved the
possibility to measure in this case SCF by interference method.
The measuring scheme of spatial coherence function of 6G Rhodamine laser by
integral method differs from the previous scheme only on the reconstruction step.
Figure 1.6b shows the scheme of wave front reconstruction and intensities
registration.
The image of the diffusive screen has been reconstructed by a small part of a
hologram, the size of which was determined by the beam diameter of He–Ne laser
(equal to 1 mm).
The whole reconstructed image was gathered by the lens photomultiplier tube
PMT-12. By moving the beam of He–Ne laser along the hologram in two mutually
perpendicular directions, integral intensity was measured of the whole reconstructed
image of the diffusive screen. The measurements were carried out on the same holograms where γ was determined by pure holographic method and by holographic one
with microphotometry of initial intensity distribution on the laser end (see Fig. 1.7). It
has given the opportunity to predetermine about the correlation of the results, which
were obtained using different methods.
In Fig. 1.9, line contours of equal intensity (integral along the whole image) are
plotted for one of the generation pulses (E = 0.03 J). Initial intensity distribution
was determined by photographic photometry method. To simplify the calculation,
19
Fig. 1.8 Study of spatial coherence function homogeneity. Reprinted from [54] with permission
where I(r 0 , r j ) is the intensity of the image in the point r 0 during the reconstruction
of a hologram along the point r j ; I(r j , r 0 ) is the intensity of the image in the point r j
during the reconstruction of a hologram along the point r 0 ; I(r j , r j ) is the intensity of
the image in the point r j during the reconstruction of a hologram along the point r j ;
index 0 is the laser end point index, as relative to which spatial coherence function
was determined, j = 1, 2, 3 is the running index of the laser end point.
As it can be seen from Fig. 1.8, laser spatial coherence function considerably
depends on the distance between laser edge points and practically does not depend
on the position of supporting point r j .
Thus, spatial coherence function is almost homogeneous function. It proved the
possibility to measure in this case SCF by interference method.
The measuring scheme of spatial coherence function of 6G Rhodamine laser by
integral method differs from the previous scheme only on the reconstruction step.
Figure 1.6b shows the scheme of wave front reconstruction and intensities
registration.
The image of the diffusive screen has been reconstructed by a small part of a
hologram, the size of which was determined by the beam diameter of He–Ne laser
(equal to 1 mm).
The whole reconstructed image was gathered by the lens photomultiplier tube
PMT-12. By moving the beam of He–Ne laser along the hologram in two mutually
perpendicular directions, integral intensity was measured of the whole reconstructed
image of the diffusive screen. The measurements were carried out on the same holograms where γ was determined by pure holographic method and by holographic one
with microphotometry of initial intensity distribution on the laser end (see Fig. 1.7). It
has given the opportunity to predetermine about the correlation of the results, which
were obtained using different methods.
In Fig. 1.9, line contours of equal intensity (integral along the whole image) are
plotted for one of the generation pulses (E = 0.03 J). Initial intensity distribution
was determined by photographic photometry method. To simplify the calculation,