Nikolay B. Voznesensky

Optical interconnection optimization based on a classical approach

New branch in optoelectronics and photonics -- integrated optical circuits as a part of hybrid optical devices and the problems of coupling efficiency in optical interconnections (OI) -- is discussed. General approach to optical circuits analysis and adjustment based on classical optics is presented. The means to improve OI light efficiency in two regions -- far-field (Fraunhofer diffraction zone) free space and near-field (Fresnel diffraction zone) vicinity of micro-optical devices are proposed. New optical elements for OI -- fiber-end mounted microlenses, their design, computer simulation and fabrication technique are considered.

Laser-based micropipettes : design, technology and applications

Micropipettes mathematical modeling and fabrication are presented. New approaches to treatment of modeling light passing through narrow glass tubes and calculation of intensity distribution in the vicinity of a tube are shown. This method is based on a layer-to-layer Fourier transform procedure which is an alternative to waveguide technique. Laser technique to produce micropipettes and to control the shape of them are described and experimental results are considered. Perspectives of medical and optical applications are discussed.

Peculiarities of laser-assisted drawing-out processing of optical probes for SNOM

The new optical scheme is built up and is used on the set-up for laser-assisted drawing-out processing (LADOP) and the technique of LADOP for optical fibers are investigated. The probes for SNOM with sizes of aperture about 100 nm were obtained and tested by SNOM. The kinetic model of LADOP is represented.

Laser-based technology of scanning near-field optical probes fabrication: study of kinetics and progress of measuring

Basic principles of laser assisted process of fiber etching for scanning near-field optical (SNO) probes formation and control technique are presented. The thermal and temporal regimes are considered in order to provide stable reproducibility and high quality of a tapered end of the optical fiber. Problems of adequate definition of the scanning imaging properties of a SNO probe are discussed. Thus an optical method of far-field registration and processing together with a new autoelectronic emission method are considered for solution of the task of a subwavelength SNO probe aperture measurement and estimation of its apparatus function.

Principles and software for photolithographic optical system alignment and tolerancing

Principles and mathematics for computer aided high precision optical system alignment and tolerancing are discussed as applied to photolithography projection lenses. All aberrations of an optical system including distortion are described by using global polychromatic Zernike polynomial expansion of the wave front aberration, so to optimize the lens quality one has to minimize each coefficient of the expansion. The procedure of aberrations measurement which is based on Hartmann test is discussed and the processing technique which easily offers to define the overfield coma, spherical aberration, distortion and astigmatism is proposed. Least squares method is used to calculate from measured data the aberration coefficients for a real system. After optimum selection of adjustable parameters axial symmetry and decentered aberrations are being compensated separately of each other.

Laser technology of SNOM-tips fabrication: process diagnostics, processing, and testing

Basic principles of laser assisted process of fiber etching for scanning near-field optical (SNO) probes formation and control technique are presented. The thermal and temporal regimes are considered in order to provide stable reproducibility and high quality of a tapered end of the optical fiber. Problems of adequate definition of the scanning imaging properties of a SNO probe are discussed. Thus an optical method of far-field registration and processing together with a new autoelectric emission method are considered for solution of the task of a subwavelength SNO probe aperture measurement and estimation of its apparatus function.

Laser-light delivery microtools based on laser technology: design, fabrication, and applications

A set of new laser-light delivery microtools (LDM) based on laser technology is investigated and discussed. Wide application of LDM in different fields of science, medicine, biology, industry and information processing is considered. Fiber optical networks in medical diagnostics and technical, civil engineering and other technological areas are discussed. The general approach based on electromagnetic field equations-transformation for all range of dimensions (mini-, micro and nanodomain) is given. Laser-assisted technology for drawing-out and for microstructuring optical tools is investigated, high-speed movie has been applied to study the process and compared with theoretical description. Finally a number of fibers and micropipettes-based medical tools and SNOM-tips has been fabricated and tested. Applications of some tools for medical operations (thermocoagulation), protein rasters preparing, SNOM-microscopy investigation have been demonstrated.

Automation of the construction creation process of the optical instrument and creations of designer documentation

The automation of the designers documentation making process gives rise to necessity in search of new possibilities for the even greater facilitation of the instruments designing process. Now in the field of optical instruments designing is felt a deficiency in the area of the software for automation of the designers documentation formation. The development of ZOOM-objectives optics requires complex and laborious work of optics-designer and creation of new forms of realization of the projects for improvement of creative work too. The given report is devoted to development of the mathematical foundation and software for a construction of the mount of the optical system automized design.

Use of vector diffraction theory in theoretical and experimental investigation of SNOM tips

An approach to the optical investigation of probes for scanning near-field optical microscopes (SNOM tips) and recognition of their near-field parameters by far-field measurements is considered. The comparison of approximate calculations of vector light field diffracted by a subwavelength aperture with more rigorous calculations of the light field passing through tapered end of a SNOM tip is presented. A numerical iterative procedure of the SNOM tip aperture reconstruction by the analytical continuation of the emerging light Fourier spectrum is presented. The approach is based on the use of plane waves covering a wide range of spatial frequencies. The results of experimental measurements and far-field data treatment with the definition of a subwavelength aperture are discussed.

Achievements in near-field investigations in Russia (IFMO SPb)

Nowadays near-field optics is one of the most attractive area for research, both for theoretical and experimental. Properly in the problem of near-field optics the most important things now are - the creation of more suitable and simpler approach to the description of near-field than MMP method and the creation of new generation of scanning near- field optical instruments (SNOI) such as microscopes, spectroscopes, light generators for lithography, etc. The key of this SNOI generation is a variety of SNOM tips with the higher resolution and transparency and else one what may be even more important, the creation of method for SNOM tips certification. Both of these problems are being investigated in Russia. Short review of other directions for near-field investigation in Russia is also given, including important applications for quantum dots studying and investigation of optical strength of SNOM tips.