Garegin O. Karapetyan

Graded index objective with a spherical end for endoscopy

A number of problems connected with producing the graded-index micro-objective with a spherical end for medical endoscopy, including the optical material and the mathematical modeling of optical and physico-chemical processes, have been considered in view of the technology of producing those objectives.

Vitreous Materials for Electrooptics

A complex approach to the development of electrooptic glasses is proposed. The approach is based on the use of the traditional methods of structural-physical investigations in combination with the Rayleigh and Mandelstam-Brillouin scattering spectroscopic techniques. The structural features of niobate glasses and their properties are considered. It is shown that niobium selectively enters into the fluctuation microinhomogeneities in the alkali borosilicate vitreous matrix. The conditions for the precipitation of sodium niobate microcrystals are determined, and their influence on the increase in the Kerr constant for glass-ceramic materials is analyzed.

GRIN elements in the interference method of glass index measurement

A new interference method for measurement of the refractive index of glass has been developed. The method is based on the Mach-Zehnder interferometry and GRIN elements are used for a scale of refractive index. Cone, pyramid or wedge elements are privileged in this method. Both the object under study and GRIN elements are placed in an oil immersion container, then oil is heated until the specimen becomes invisible. For such a situation the interference fringes produced by the GRIN standard are analyzed. The accuracy of refractive index measurements is equal to +/- 0.00001.

New fabrication technology of micro-objectives for endoscopy

Technological possibilities of making wide-angle micro-objectives for endoscopes out of separate modules with different refractive indexes (RI) have been considered and the corresponding investigation of optical calculations has been done. Aspherical surfaces in modules was achieved without any mechanical treatment.

New technology of endoscopy micro-objectives manufacture

The new approach to the fabrication of wide angle micro objectives made of separate modules has been considered and the corresponding investigation of optical calculations has been done. The modules are made of two glasses with different refractive index (RI) divided by aspherical surface. Aspherical surface in modules was achieved without any mechanical treatment.

Optimization of the graded-index microlens technology

A number of problems connected with producing the graded-index micro-objective with a spherical end for medical endoscopy including the optical material and the mathematical computer programs for optical and technological calculation have been considered in view of the technology of producing those objectives.