Site: Vavilov State Optical Institute
Birzhevaya liniya, 12
St. Petersburg 199034
Russia
Telephone: (812) 218 48 92
Fax: (812) 350 64 73, 350 99 93

Date Visited: October 25, 1993

Report Author: J.W. Doane

ATTENDEES

WTEC:

J.W. Doane
J. Larimer
E.C. Urban
Z. Yaniv

HOSTS:

Dr. Sergey N.

Dr. Igor A. Malyshev

Dr. Vladimir S. Bedryagin

Dr. Arkadii P. Onokhov

Dr. Irina I. Solovieva

BACKGROUND

The Vavilov State Optical Institute is a basic research institute with a mission to cover the important fields of optical science and technology.

The WTEC team was met by scientists who relate to the display field. Dr. Tomilin, one of the principal scientists working in the display field, could not be present for this visit, but was represented by Dr. Irina Solovieva. A discussion with each of the other attendees of the meeting follows.

RESEARCH AND DEVELOPMENT ACTIVITIES

Image Compression and Image Processing

This activity is headed by Dr. Igor A. Malyshev. In this activity, the scientists worked out a method of image compression. In this effort, they received compression ratios of 16 for 0.5% accuracy and 64 for 1% accuracy. These results were reached on the basis of neural networks, but can also be used for economical image archiving and for high-speed transmission of graphical information from the central processing and storage units to distant peripheral user display terminals or indicators. The image compression and image processing activity has been developed for precise location of space vehicles. Other applications of interest include the use of neural networks to solve problems of image processing and recognition, and to build effective automatic tracing and control systems. In the field of image processing, neural networks are successfully used for image segmentation on the basis of its stereo-disparity, texture features, and colors.

Liquid Crystal Applications to Laser Systems

Under the direction of Dr. Vladimir V. Danilov, the institute's work on liquid crystal applications to laser systems involves a variety of studies. Included are: interaction between laser light and liquid crystals, transient processes in photoinduced systems, nearfield structures, phase conjugation, dynamical holography, lumped feedback, and work on cholesterics. Details of this work can be found in the papers listed in the references section at the end of this report. Dr. Danilov has also studied dynamic holography and bistable cells based on helical structures.

Spatial Light Modulators for High-Resolution Projection TV

This work, conducted under the direction of Dr. Arkadii P. Onokhov, involves the development of light-addressed (laser- addressed) spatial light modulators using ferroelectric liquid crystals. Ferroelectric liquid crystals are used to gain the speed necessary for television applications and also for use as modulators in fiber optic communication and phase correction in telescopes. The FLC device has sample times of 5 žsec making use of electroclinic switching. Dr. Onokhov works in collaboration with Professor Blinov in Moscow and also with Professor Ligorval in Sweden. Photoconductors used in SLM consist of ZnSe, a-Si, and organic photoreceptors; a-Si is deposited by magnetron sputtering where it obtains five orders of magnitude change. The a-Si is deposited at the Ioffe Institute in the laboratory of Academician J. Alfiurov, Vice President of the Academy of Sciences. A dielectric mirror was shown that was made of Si, SiO₂ layers. Details in construction of the mirror were described as proprietary. They also obtained infrared SLMs at 10.6 žm wavelength in the scattering mode. At present there are no plans in Russia for manufacturing this device. More information can be found in the site report on the Ioffe Institute.

Laser Treatment of Services

Work on laser treatment services is also under the direction of Dr. Arkadii Onokhov. Extensive use is made of laser deposition of thin-film materials for deposition of dielectric films and transparent coatings. The Vavilov Institute has a laser process for smoothing the glass surfaces that is better than the usual polishing technique. The laser is a CO₂ 100-W laser. The laser fuses cracks, removes bumps, removes water, and so forth. The smoothing device can handle an area of 7 m x 7 m, and the process takes approximately ten minutes.

Associated Company

Dr. Onokhov is also president of a small company called PeterLab, Ltd. PeterLab is an R&D company and does not yet see itself in a production or manufacturing mode. Activities of PeterLab include: development of ferroelectric liquid crystal materials; construction of spatial light modulators using nematics and FLCs; special glass treatment for variable distribution of the refractive index; and laser ablation of metals, oxides, and semiconductors on treated substrates for very strong adhesion.

Visualization of Surface Defects Using Liquid Crystals

This work is in the department of Dr. Tomilin and the work of Dr. Irina Solovieva. They have developed a method to observe damages in metal mirrors for lasers. By spinning they coat a 1-micron thick film of a nematic liquid crystal on the surface of the metal. The liquid crystal is sensitive to local magnetic fields in the metal and will image those local magnetic fields. The defects in the metal are clearly visible when observed with polarized light. In this group there are also studies of light scattering and calorimetry in liquid crystal materials.

Special Glasses

This is the work of Professor Leonid Glebvov, who was not present at the meeting. The Vavilov Institute is conducting no work on glass substrates for displays.

Holography

The WTEC team visited a showroom that featured a large number of spectacular holograms. They were magnificently presented, and a wide variety of holograms were shown.

SUMMARY

Display-related work at the Vavilov State Optical Institute includes an interesting laser-addressed FLC spatial light modulator that could be used for high-definition television. There would be interest in contacting someone who wants to commercialize this technology. Use of unique techniques for laser treatment of glass is an exciting technology that should be further explored by those interested. A wide breadth of optical technologies are studied at the Vavilov Institute.

REFERENCES

1993. "The Dynamics of Cholesteric Liquid Crystal under the Influence of an IR-Radiation Pulse." Mol. Mat. 2:97- 101.

1990. "Resonant-Thermal Optical Hysteresis in Liquid Crystals." Mol. Cryst. Liq. Cryst. 192:279-283.

"Some Problems of Liquid Crystal System Photodynamics." Prepublication.

"TEA-CO2 Lasers with Intracavity LC Modulators." Prepublication.