3 Holographic Interferometry for Studying …
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of the holographic cardiograph. At the same time to implement the experimental
sample of this device, there was just one step left.
Later L.V. Tanin, the author, managed to realize another idea in an experimental
sample of the laser specklometer, which is successfully used today as a device for
diagnostics in neurological practice (it is described more detailed in Chap. 5).
3.1 The Holographic Method of Contouring of Static
and Time-Changing Surfaces Using Multi-long-Wave
Dye Laser Radiation with Laser Pump and Resonance,
Absorbing and Optically Active Media
3.1.1 The Holographic Method of Surface Relief Contouring
Two- and Four-Long-Wave Dye Laser Generation
Mode with Laser Pump and Regulated Spectral Interval
Between Them
Let us consider the possibility of using rhodamine 6G laser with laser pump reconstructed over the radiation spectrum in the study of surface relief with the help of
colliding beam holography [90, 91].
The surface hologram obtained in the two-long-wave radiation regime from
two independent lasers through wave front reconstruction makes surface relief
contour [69]. The same hologram obtained in multi-long-wave radiation regime gives
narrower bands as it is shown in the work [71] as they appear due to multi-beam
light interference. But this method has a disadvantage: Dispersion of the hologram
obtained with an inclined reference beam leads to transverse shift of the reconstructed
images corresponding to different wavelengths. This leads not only to contour distortion but also to band localization at a significant distance from the surface [92]. To
eliminate hologram dispersion and these undesired effects, the scheme of hologram
recording in colliding beams was used [22, 28–31]. Thus, the colliding beam holography method using the one- and multi-long-wave radiation generation regime of
dye lasers makes it possible to manage the spatial resolution and sensitivity of the
holographic method of contouring of static and time-changing surfaces depending
on the step between the spectrum components and the number of these spectral
components.
Increasing sensitivity of holographic contouring methods occurs at the decrease
of the depth interval between the bands that is best provided while using a laser
with gradually changing wavelength with regulated spectral interval. But with the
growth of this interval between two wavelengths the shift between corresponding
points on the object increases as well that leads to decorrelation and worsening of
band luminous efficiency. The accuracy of calculation of interference fringe center
can be enhanced through the half-width decrease.
189
of the holographic cardiograph. At the same time to implement the experimental
sample of this device, there was just one step left.
Later L.V. Tanin, the author, managed to realize another idea in an experimental
sample of the laser specklometer, which is successfully used today as a device for
diagnostics in neurological practice (it is described more detailed in Chap. 5).
3.1 The Holographic Method of Contouring of Static
and Time-Changing Surfaces Using Multi-long-Wave
Dye Laser Radiation with Laser Pump and Resonance,
Absorbing and Optically Active Media
3.1.1 The Holographic Method of Surface Relief Contouring
Two- and Four-Long-Wave Dye Laser Generation
Mode with Laser Pump and Regulated Spectral Interval
Between Them
Let us consider the possibility of using rhodamine 6G laser with laser pump reconstructed over the radiation spectrum in the study of surface relief with the help of
colliding beam holography [90, 91].
The surface hologram obtained in the two-long-wave radiation regime from
two independent lasers through wave front reconstruction makes surface relief
contour [69]. The same hologram obtained in multi-long-wave radiation regime gives
narrower bands as it is shown in the work [71] as they appear due to multi-beam
light interference. But this method has a disadvantage: Dispersion of the hologram
obtained with an inclined reference beam leads to transverse shift of the reconstructed
images corresponding to different wavelengths. This leads not only to contour distortion but also to band localization at a significant distance from the surface [92]. To
eliminate hologram dispersion and these undesired effects, the scheme of hologram
recording in colliding beams was used [22, 28–31]. Thus, the colliding beam holography method using the one- and multi-long-wave radiation generation regime of
dye lasers makes it possible to manage the spatial resolution and sensitivity of the
holographic method of contouring of static and time-changing surfaces depending
on the step between the spectrum components and the number of these spectral
components.
Increasing sensitivity of holographic contouring methods occurs at the decrease
of the depth interval between the bands that is best provided while using a laser
with gradually changing wavelength with regulated spectral interval. But with the
growth of this interval between two wavelengths the shift between corresponding
points on the object increases as well that leads to decorrelation and worsening of
band luminous efficiency. The accuracy of calculation of interference fringe center
can be enhanced through the half-width decrease.