EU-STCU #4884 Project

Executive summary

Up to date there are no efficient acousto-optic сells in the industrial fabrication and indeed at their designing there is no methodology which could improve their efficiency, especially in the case of powerful laser radiation control. For these purposes acousto-optic materials with high radiation stability and small attenuation of high frequency acoustic waves are needed. This slows down substantially the development of those branches of industry, experimental technologies or scientific equipment, which require powerful light sources or where an advantage of acoustooptic applications is evident.Thus, modern development of information technology puts new research problems related to the industrial implementation of highly efficient acoustoptic cells suitable for the control by powerful laser radiation at frequencies up to 1 GHz.

Working elements of acouctooptic cells are usually made from low-symmetry crystalline materials, in particular, when these cells are based on the effects, characterized by the third or higher rank tensors. Such materials however exhibit essential anisotropy of the acoustooptic effect. Hence, it is necessary to find extreme values of the effect and the respective geometry of acoustooptic interaction in order to increase the efficiency of their application.

Final aim of project is the development of the methodology of the creation and optimization of acoustic-optic cells of crystalline materials for the most efficient high-frequency control of the powerful laser radiation.

During the reporting period the following approaches and methods were used:

1. The method of manufacture of necessary crystal cuts preparation and techniques for the measurement of their optical parameters, including basing on X-ray structure analysis based orientation, abrasive free polishing, mechanical polishing, chemical-mechanical polishing.
2. The method for crystal quality control by means of the visual observation of interference conoscopy figures in polarized light.
3. The dynamic echo-pulse method for the determination of longitudinal and transverse acoustical wave velocities in crystals.
4. Eectron speckle interferometry technique for the determination of elastic coefficients.
5. The interferometric method of two-fold measurements for determination of the all tensor components of piezooptical and electrooptical effects in crystal materials of different symmetry.
6. The polarization-optical method for the measurement of piezooptical coefficients using the birefringence.
7. The method for the calculation of all the components of elastic-optic effect tensor (including the absolute value and the sign) in crystalline materials of different symmetry classes for different thermodynamics conditions.
8. Method of research of basic technical parameters: central frequency of managing signal and diffraction efficiency of modulation for the acousto-optical modulator of light.

The project was divided in three parts: 1) upgrade of the experimental equipment and measurements on selected crystal materials; 2) 3D analysis of the spatial anisotropy of induced effects in selected crystals; 3) the development of the methodology of the most efficient AO cell design and the fabrication of AO-cell prototype for the high-frequency control of the powerful laser radiation.

Main technical achievements

Technological equipment and experimental set-ups have been upgraded. Experimental techniques have been improved. The patent describing the method of piezo-optic coefficients measurements has been declared. In particular:

• the equipment for the measurement of acoustical wave velocity in different class symmetry anisotropic crystals by the dynamic echo-pulse method was modernized;
• the modernization of the equipment for pressure measurements on the base of Mach-Zender interferometer has been completed. The equipment is used for more precise determination of all tensor components for piezo-optical effect in low symmetry crystals. Possible errors during the measurements of absolute piezo-optical coefficients were eliminated.

The search for prospective acoustic-optic crystals has been performed. The objects for further studies have been selected.

The X-ray structure analysis, crystal cutting, orientation, grinding and polishing of samples of LiNbO3 and LiNbO3:MgO, galliumphosphide (GaP) single crystals as well as calcium tungstate and calcium molibdate crystals were performed.

• The necessary acoustic, electric-optic and piezo-optic coefficients on crystalswere performed. The results of these measurements have been analyzed.
• Piezo-optical path difference coefficients and their temperature dependence for GaP, calcium tungstate crystals were measured using the polarization-optical set-up.

Induced piezo- changes of the optical path in calcium tungstate were measured exploiting an interferometric Mach-Zender and Fizeau set-up.

On the basis of the developed methodology of the 3D spatial analysis of induced effects methodology and the search for the maximum value of the acoustooptic figure of merit in crystals of different symmetry were developed:

• optimization of the geometry of the piezo-optical interaction for langasite, pure and MgO doped lithium niobate, calcium tungstate and gallium phosphitehas been performed;
• indicative surfaces were constructed and the extreme values of acousto-optical quality parameter were obtained for pure and MgO doped lithium niobate, barium beta-borate and gallium phosphide.

Activities related to the development and testing of high-efficiency acousto-optical modulator:

• crystalline samples of lithium niobate with the extreme values of acousto-optical figure of merit were made for the cases of isotropic and anisotropic diffraction of light;
• using the experimental Dixon method and created acousto-optical set-up the value of acousto-optical figure of merit of fabricated crystalline samples was measured for the case of isotropic diffraction of light at for longitudinal acoustic wave;
• the operating model of high-efficiency acousto-optical light modulator was designed the estimation of its efficiency was performed.

Marketing studies of companies dealing with crystal growth, crystalline materials studies and acoustic-optic devices fabrication have been completed.

Cooperation with foreign collaborators

Foreign collaborators are aware of the current project progress; regular discussions with collaborators were organized via e-mail. The results of the investigations were published in joint papers co-authored by foreign partners (“Optics & LagerTechnology”and“OpticalMaterials” journals). During the visit of the project manager, Anatoliy Andrushchak, to Universite D’Angers, France the plan of the further joint experimental studies was agreed with the collaborator of the project, prof. B.Sahraoui.

The following conference oralreportswere presented:

• Optimization of the effective crystal cutoff searching technique for acousto-optic light modulators // V International Optical Congress “Optics–XXI century” (Topical Meeting on Optoinformatics), 15–18 September, 2008, Saint-Petersburg, Russia;
• Design of optimization technique for electro- and acousto-optical interactions of light in crystalline materials // IX International Conference on Laser and Fiber-Optical Networks Modeling, 2-4 October, 2008, Alushta, Crimea, Ukraine;
• Efficiency increasing of the light modulators on the base of spatial anisotropy analysis of electrooptic effect // XII open scientific and technical conference of the teaching staff for the Institute of Telecomunication, RadioelectronicsandElectronicDevices, Lviv Polytechnic National University, 5-7 April 2009, Lviv, Ukraine;
• Photoelasticity of CaWO4 crystals // Abstract of the International Scientific Workshop «Oxide Materials for Electronic Engineering – fabrication, properties and application». – Lviv(Ukraine). –June22-26, 2009. – P.185.
• Calcium Tungstate is a Perspective Acousto-Optic Material. Photoelastic Properties. // Modern problems of radio engineering, telecommunications and computer science - Proceeding of the 10th International Conference TCSET’2010, 23-27 February 2010, Lviv-Slavske, Ukraine;
• Research of frequency dependences of capacities of inter digital transformers for excitation of byvolumeacoustic waves // XIІІ Opened scientific and technical conference of profesor-lecturer composition of Institute of telecommunications, radioelectronics and electronic technique (ITRE) of Lviv Polytechnic Nationa lUniversity from problems of electronics : Thesis of report. – Lviv (Ukraine), 2010;
• Static fotoelasticity of calcium tungstate crystals by length path // XIІІ Opened scientific and technical conference of profesor-lecturer composition of Institute of telecommunications, radioelectronics and electronic technique (ITRE) of Lviv Polytechnic National University from problems of electronics : Thesis of report. – Lviv (Ukraine), 2010;
• Angular stability maximums of the indicative surfaces of induced effects // XIІІ Opened scientific and technical conference of profesor-lecturer composition of Institute of telecommunications, radioelectronics and electronic technique (ITRE) of Lviv Polytechnic National University from problems of electronics : Thesis of report. – Lviv (Ukraine), 2010;
• A New Method for Refractive Index Measurement of Isotropic and Anisotropic Materials in Millimeter and Submillimeter Wave Range. // Proceeding of the 18th International Conference on Microwave, Radar and Wireless Communications MIKON-2010, Vilnius (Lithuania);
• Relaxation static photoelasticity in ferroelectrics // ХХІІ International conference, «Relaxational phenomena in solids», Rps-22. Thesesofreports. 14–17 September 2010. – Voronezh. P. 127-128.

Publications

During the report period the following papers were published:

1. Andrushchak A.S. Spatial anisotropy of electro-, piezo- and acousto-optic effects in crystalline materials of solid electronics. Approbation on example of LiNbO₃ and LiNbO₃:MgO crystals. Part I. Complex method design for anisotropy 3d-analysis of induced optical effects in crystals // Herald Nation. Univ. “Lvivs’ka Politechnika” (Electronics) .- 2008.-No.619.-P.165-171.
2. Laba H.P., Yurkevych O.V., Karbovnyk I.D., Kaidan M.V., Dumych S.S., Solskii I.M., Andrushchak A.S., Spatial anisotropy of electro-, piezo- and acousto-optic effects in crystalline materials of solid electronics. Approbation on example of LiNbO₃ and LiNbO₃:MgO. Part II. Completing of elastic and piezoelectric coefficients matrix for LiNbO³ and LiNbO³:MgO crystals // HeraldNation. Univ. “Lvivs’ka Politechnika” (Electronics). - 2008.-No.619.-P.172-180.
3. Demyanyshyn N.M., Mytsyk B.G., Andrushchak A.S., Kost’ Ya.P. Optimization of the effective crystal cutoff searching technique for acousto-optic light modulators // Proceedings of V International Optical Congress “Optics–XXI century” (Topical Meeting on Optoinformatics). – 15–18 September 2008. – Saint-Petersburg, Russia. – P. 335–338.
4. Andrushchak A.S., Mytsyk B.G., Demyanyshyn N.M., Kaidan M.V., Yurkevych O.V. Design of optimizationtechnique for electro- and acousto-optical interactions of light in crystalline materials // Proceeding of 9-th International Conference on Laser and Fiber-Optical Networks Modeling (LFNM 2008). – Alushta, Krimea (Ukraine). – October 2-4, 2008 - P. 66-68.
5. Andrushchak A.S., Kaidan M.V., Yurkevych O.V., Mytsyk B.G., Solskii I.M. // Simulation and information technologies. Collection of scientific works of Institute of simulation problems for NAS of Ukraine. – 2008. – N.49. – P.194-201.
6. Mytsyk B.G., Andrushchak A.S., Kost’ Ya.P., Solskii I.M. Piezooptical effect in LiNbO₃:MgO crystals // J. Phys. Invest. – 2008. – V.12, No.3. – P.3702(1-5).
7. Mytsyk B.G., Andrushchak A.S., Demyanyshyn N.M., Kost’ Y.P., Kityk A.V., Mandracci P., Schranz W. Piezo-optic coefficients of MgO doped LiNbO³:MgO crystals // AppliedOptics - 2009. - V.48, No.10. - P.1904-1911.
8. Andrushchak A. S., Yurkevych O.V., Mytsyk B.G., Sahraoui B., Kity A.V. Elastic and photoelastic constants of pure and MgO doped lithium niobate crystals // J. Applied Physics. – 2009. – V.106. – P.073510(1-6).
9. Andrushchak N.A., Bobitskii Ya.V., Maksymyuk T.A., Syrotynsky O.I., Andrushchak A.S., Karbovnyk I.D.. A New Method for Refractive Index Measurement of Isotropic and Anisotropic Materials in Millimeter and Submillimeter Wave Range. // Proceeding of the 18th International Conference on Microwave, Radar and Wireless Communications MIKON-2010, Vilnius (Lithuania). P.273-275.
10. Andrushchak A. S., Kaidan M. V., Chernyhivskiy Je. M., Yurkevych O. V., Maksymyuk T. A. , Mytsyk B. G. , Kityk A. V. Application efficiency increasing of LiNbO₃:MgO and GaP crystals for acoustooptical high frequency control of powerfull laser irradiation // Proceeding of 10-th International Conference on Laser and Fiber-Optical Networks Modeling (LFNM 2010). – Sevastopol, Сrimea (Ukraine). – September 10-14, 2010.-P.172-174.
11. Mytsyk B.G., Demyanyshyn N.M., Andrushchak A.S., Kost’ Ya.P., Parasyuk O.V. and Kityk A.V. Piezooptical coefficients of f La₃Ga₅SiO₁₄ and CaWO₄ crystals: A combined optical interferometry and polarization-optical study // Optical Material. – 2010. – V.33, No.1. – P.26–30.
12. Kushnir O.S., Yurkevych O.V., Andrushchak A.S. Angular stability of maxima of the indicative surfaces of physical effects induced with externa lfields // Herald Nation. Univ. “Lvivs’ka Politechnika” (Electronics) .- 2010.-No.681.-P.197-204
13. Kost Ya.P., Andrushchak A.S., Mytsyk B.G. Static photoelasticity of retardation of tetragonal crystals // Herald Nation. Univ. “Lvivs’ka Politechnika” (Electronics) .- 2010.-No.681.-P.118-126
14. Andrushchak A.S., Chernyhivsky E.M., Gotra Z.Yu., Kaidan M.V., Kityk A.V., Andrushchak N.A., Maksymyuk T.A., Mytsyk B.G., Schranz W. Spatial Anisotropy of the Acoustooptical Efficiency in Lithium Niobate Crystals // J. AppliedPhysics. – 2010. – V.108. – P.103118(1-5).

The list of received patents:

1. Andrushchak A.S., Tybinka B.V., Andrushchak N.A., Dumych S.S. Interferometric-rotating method for refractive index determination o foptical materials. Paten tUkraine No. 39155 from 10.02.2009, Bul. No.3;
2. Mytsyk B.G., Andrushchak A.S., Kost’ Ya.P., Yurkevych O.V. Polarization-optical device for determination of induced optical path in materials. Patent Ukraine No. 39218 from 10.02.2009, Bul. No.3.

Prospects of further developments

The final project result – design procedure of the interaction efficiency optimization between the light and applied electric field, mechanical stress or acoustic wave in anisotropic materials of all the symmetry classes is a high technology and scientifically capacious product. That is why it will be competitive and good advertisement company with a corresponding marketing supply will provide a large demand. One expects also, that small companies are not interested in buying of the final product, but will have a possibility to use our service for measuring all tensor components of elastic, piezoelectric, electro-, piezo- and elasto-optical effects in crystals on our own base. Therefore it is necessary to provide the conditions for production and sales as well as the financial support of service for all potential consumers. To provide this the following steps are expected to be done:

1. Market research of potential consumers interesting by our product or service in Ukraine and abroad.

This task was almost completed during the project.

2. Business relations with potential consumers and marketing support of the product and service:
• the business relations will be set according to the list of potential product consumers having been created during the project;
• we will study the companies concerning a specific of their needs, such as required special investigation conditions or technical characteristics of the anisotropy crystalline materials and devices created on their base in order to prepare a contract or a business-plan which could solve their problems;
• the further steps will be undertaken in the intellectual rights protection, including the analysis of a possibility of licensing the developed innovations and prepare foreign patents on the designed procedure;
• the advertisement of the final product and service and the further approbation of the project results will be continued during international scientific practical conferences and seminars and in publications (national and international journals).
3. The program of the product introduction and market implementation of the corresponding service
• Switching to the program of the product introduction and the realization of the technical support will depend on the stock of orders. Most probably we expect to get the orders on a rather limited amount of the product. Therefore if such order occurs the following steps will be undertaken:
• a number of actions will be carried out in the cooperation with the metrology service to develop a metrology support of the developed procedure;
• we will analyze possibilities of buying the necessary materials and parts for a serial production of highly efficient crystalline materials for acousto-opitcal cells design;
• we will carry out the negotiations with potential producers, for example NVO “Karat” (Lviv) about small serial productions of the product;
• after signing the financial contract with a potential consumerthecorresponding production process will be organized.

1. Simultaneously, we will try to get an additional financial support for a further modernization and improvement of proposed procedure via grants application in EU, USA, Japan and other countries.

2. We will continue actions in the direction of advertisement of the final product and search for other potential consumers of the product and service by means of:

• participating in international scientific practical conferences and seminars;
• publication of results in national and international journals;
• modernization and expansion of the project website.

The results of this design and construction project may be interesting to the companies which deal with the production of devices containing functional elements made of anisotropic materials, namely:“Central construction bureau “Arsenal”, Kyiv, Open Action Association “Tochprylad”, Kharkiv, “Astroprylad”, Kyiv; American IntraAction Corp., Quanta Tech. Inc, Electro-Optical Products Corp., AOTF Technology Inc., Aurora Photonics Inc., Photonic System Inc. (PSI), SOCC Optoelectronics (USA), Inc., Boulder Nonlinear Systems, Inc., IMRA America, Inc.; Germany Landwehr Electronic GmbH, APE GmbH, IPAG - Innovative Processing AG,GTU LaserTechnic Gmbh; Chinese Dayoptics, Inc.,Castech-Phoenix Inc.(CASIX); French FASTLITE, A.A. Opto-Electronique, English AG Electo-Optics, Gooch and Housego PLC, Leysop, Ltd., Lambda Photometrics, Gooch & Housego PLC; Russian Open Action Association “Concern Russian defense technologies, Moscow, Holo Great, St. Petersburg and others. Potentially interested companies are also the producers of optical crystal materials, i. e. companies that require the express analysis of optical parameters of crystalline materials, for example: Ukrainian NT Concern “Institute of monocrystals” Kharkiv, Production-research union “KARAT”, Lviv; ELENT A, Dnipropetrovsk; Russian Laboratory of crystal growth in the Institute of mineralogy and petrography, Novosibirsk, ELAN+, St. Petersburg; Swede Hamamatsu Photonics Norden AB; American Isomet Corp., NEOS Technologies Inc., Crystal Technology Inc. and others.

© Center of Excellence for Innovative Technologies and NanoEngineering

Address: Ukraine, Lviv, 5 Kn. Romana str., Office 620

Tel/Fax: +38(032)258-30-82, email: anatolii.s.andrushchak@lpnu.ua