Experiments of real time holographic interferometry were performed with circular and linear polarized laser radiation.
An object with a metallic and dielectric part of the surface was studied. It was found that holographic interferometry on
the metallic surface can easily be understood with different combinations of the polarization of the different waves.
However, unexpected results were found for experiments with the dielectric. The experiments can be explained
assuming that the object wave of a diffuse scattering dielectric is different for illumination with right and left circular
polarized radiation. Thus, the interference structure of a hologram originating from these waves is also different, in spite
of the fact that the image of the object seems to be the same. A theoretical analysis can be performed extending the
well-known Jones matrices for radiation depolarized by dielectrics. Theoretical and practical consequences are
discussed that refer to the polarization structure of light and to holographic interferometry.
DESA emulsions represent layer systems based on ultra-fine grained silver halide (AgX) technology. The new
layers have an excellent performance for holographic application. The technology has been presented repeatedly in
recent years, including the emulsion characterization and topics of chemical and spectral sensitization. The paper gives
a survey of actual results referring to panchromatic sensitization and other improvements like the application of silver
halide sensitized gelatine (SHSG) procedure. These results are embedded into intensive collaborations with small and
medium enterprises (SME's) to commercialize DESA layers. Predominant goals are innovative products with
holographic components and layers providing as well as cost effectiveness and high quality.
The DESA material is an ultra-fine grained silver bromide emulsion referring to the name of its four inventors (D)uenkel, (E)ichler, (S)chneeweiss, (A)ckermann of the University of Applied Sciences in Berlin, Germany. The thickness of the dried layer is between 5 and 7.5 μm, and the mean grain size is by about 15 nm, as determined by TEM. During manufacturing, emulsion precipitation and coating are separated strictly from spectral and chemical sensitization. Thus, a high performance could be obtained. Resolution is estimated higher than 8000 lp/mm. Sensitivity amounts to 80 up to 120 μJoules/cm2 for maximum diffraction efficiency by recording Denisyuk white-light reflection holograms at 632,8 nm (HeNe laser). The paper provides an insight into fundamentals of the ultra-fine grained silver halide technology together with new challenges for further developments under theoretical and practical aspects.
Holography is the most fascinating technology for three-dimensional imaging. But despite of many
decades of research, the seek for an ideal recording material has never been given up. From all
ultra-fine materials, silver bromide emulsions with very small grain sizes have the highest
sensitivity. In recent years however, many traditional manufacturers discontinued their production.
Meanwhile, newcomers succeeded in manufacturing emulsions which are very suitable for
holography, concerning extremely high resolution, brigthness and sensitivity1. But two problems
may still linger: First, the deficient market situation for production and application on this field.
Second, the reputation of the system of being extremely complicated for laboratory preparation.
In such a crucial situation, the authors have succeeded in presenting a laboratory procedure for
making do-it-yourself materials available to any expert who is well versed in holography, and who
disposes of normal darkroom equipment2. The methodology is based on precipitation using the
traditional double-jet method according to Thiry and predecessors3. But sensitization is carried out
by a diffusion process according to the procedure as proposed by Blyth et al.4 Thus, precipitation
and coating on one side and sensitization on the other one are separated strictly from one another.
Efficient desaltation is an important process too, warranting the high opto-mechanical quality of the
The material has been sensitzed for HeNe-Laser radiation (632,8 nm) only up to now. The mean
diameter of the silver bromide grains is about 15 nm, as determined by transmission electron
microscopy (TEM). Phillips-Bjelkhagen Ultimate (PBU) or Fe3+ rehalogenation bleach are applied
successfully5-6. In final result, a new generation of holograms with ultra-high resolution, proper
contrast, excellent sharpness and light brightness has been obtained.
Holography belongs to an advancing technology where the search for an ideal recording material is still going on. Of these materials, the ultrafine grain silver bromide emulsions are unsurpassed in sensitivity. But in recent years many traditional manufacturers discontinued their production. In such a critical situation, the authors have succeeded in developing a new technology to make do-it-yourself materials of very high quality. The procedure involves elements of two different methods: The traditional double-jet method by pouring silver nitrate and potassium bromide into a vigorously stirred gelatin solution, and a diffusion process to sensitize the coated layer efficiently. The material has been sensitized for He/Ne-laser radiation by 632.8 nm. Denisyuk holograms of real 3D-objects were obtained in ultrahigh resolution, excellent brightness and clarity with CW-C2 developer and PBU rehalogenation bleach according to Bjelkhagen et al. The material is characterized by TEM, reflexion spectroscopy, and other methods. The new results have been involved in university education already with great success. The fundamental principles of the methodology as well as new results by application in intellectual and hybrid systems were reported.