A method for fabrication of mechanical elements (microturbines) that receive torque from vortex optical beams is proposed. Experimental results on fabrication of multiple microturbines are presented. Shapes of the microturbines are measured using an optical microscope, ZYGO white-light interferometer, and electron microscope.

We describe a process for fabrication of optical diffraction elements based on localized thermochemical oxidation of a thin chromium film. Once the recording procedure has been completed, the unoxidized chromium is removed, thereby forming a microrelief consisting of transparent chromium oxide. (C) 2016 Optical Society of America.

Laser irradiation of thin molybdenum films with a thickness of less than 100 nm is studied. An experimental hypothesis in accordance with which films of refractory metals can be laser-ablated owing to the formation of an intermediate oxide phase is experimentally proven. A threefold decrease in the thickness of the ablation region under the action of scanning laser radiation is interpreted.

The possibility of forming a microprofile in diffractive optical elements by thermal oxidation of thin molybdenum films is analyzed. It is shown that the gain in the thickness of a starting film in the thermal oxidation process may reach a threefold value, with the optical quality of the surface preserved.

The problems of laser ablation of molybdenum films that are related to the formation of topological patterns of contact masks are discussed. The thermal oxidative degradation of thin molybdenum films under high-intensity laser irradiation is analyzed. The results of theoretical estimations are compared with the Raman data on the chemical composition of molybdenum oxide.

We perform a comparative numerical study of the formation of closely spaced focal spots in the focal plane with diffraction gratings and binary optical elements matched with the Hermite-Gaussian modes. It is shown that low-index modes provide the generation of good-quality focal spots and relative tolerance to chromatic dispersion. Experiments with pulsed and tunable lasers have shown that phase optical elements matched with TEM(1,0) and TEM(1,1) modes show promise for creation of arrays of closely spaced focal spots.

Experimentally investigated a focusing of inhomogeneously polarized laser beams formed by the sector polarizing plates. The analysis of noise distortion beams formed different types of plates is performed. Focusing is implemented by a micro-objective with high numerical aperture and by a diffraction axicon with moderate numerical aperture. It's experimentally shown that beam distortion by noise have a little effect on the intensity distribution in the center of the focus area due to its high frequency nature. It is in agreement with the simulation results.

We report the results of studies on the possibilities of controlling laser ablation by changing the polarisation state and the intensity distribution in the focal plane of the beams of high-power femtosecond radiation by means of beam diaphragming and controllable phase modulation using binary-phase plates. The latter provides the adjustment of correlation between the electric field components in the focus area. Based on the results of numerical modelling of the distribution of the electric field components in the focus area, an explanation of the mechanism of formation of the unusually shaped craters is given.

We investigate the parameters of microstructures obtained by laser thermochemical writing in molybdenum films of thickness 17, 35, and 70 nm deposited on glass and quartz substrates. Graphs of the spatial resolution of the microstructures as a function of the laser power are plotted for different substrate materials. It is shown that a higher spatial resolution of the microstructures can be achieved in the molybdenum films with a 17-nm thickness.

We investigate theoretically and experimentally distribution of electric field components in a focal plane at rotation of a plate with pi-phase jump placed in the focused beams. We analyze the polarizing sensitivity of the various apertured metalized probes on the basis of comparison of theoretical and experimental results. It is shown, that with growth of diameter of the aperture window of a probe an essential change of sensitivity occurs in favor of transverse components of the electric field and growth of signal transfer factor of a probe.

The problem of reducing the thickness of the lines of contact pattern masks used in the formation of micro-relief of diffractive optical elements (DOEs) and produced by laser ablation of thin films of refractory metals. For contact mask of DOEs on molybdenum films with thickness of 40 nm using a laser ablation patterns recorded with elements of the picture width 0.25–0.3 µm. This is approximately 3 times smaller than the characteristic dimensions, obtained by thermochemical recording chromium films of the same thickness in the standard process. Reactive ion etching in an inductively coupled plasma through a mask was formed micro-relief height up to 300 nm in a quartz substrate. We have shown promising applications of thin films of molybdenum as a metallic mask in the formation of microrelief of DOEs.

We investigate theoretically and experimentally distribution of electric field components in a focal plane at rotation of a plate with p-phase jump placed in the focused beams. We analyze the polarizing sensitivity of the various apertured metalized probes on the basis of comparison of theoretical and experimental results. It is shown, that with growth of diameter of the aperture window of a probe an essential change of sensitivity occurs in favor of transverse components of the electric field and growth of signal transfer factor of a probe.

This paper is devoted to the application of a well-known genetic algorithm for optimization of diffractive optical element forming pre-given axial intensity distribution. Computer simulation results and experimental research are presented.

With enhanced performance of computing facilities the iterative design of phase diffractive optical elements (DOEs) has become widely accepted. A great number of up-to-date technologies for DOE fabrication make use of the approximation of the commonly continous DOE phase function by a picewise continuos (quantized) function. This is the reason why constructing iterative procedures for the design of quantized DOEs (DOEs with quiantized phase function) has become topical. Designing quantized DOEs with small number of quantization levels using Fienup-type iterative algorithms (or IFTA-algorithms) is hampered by the necessity to solve the diffractive theory inverse task at every iteration. Besides, using of such algorithms cannot guarantee convergence to global optimum. The use of stochastic procedures does not make it necessary to solve the inverse task. This paper deals with application of the known genetic stochastic procedure to determine the optimum of the function of many variables to designing quantized DOEs forming pre-given intensity distribution along an axial focal zone. Computer simulation results as well as experimental results are presented.

Of a high interest now are the light fields with spatially inhomogeneous polarization state. These fields give new possibilities for many aspects of optical science and engineering. We consider a new effective method for the synthesis of light fields with predetermined polarization structure by means of specific diffractive optical element (DOE).

We discuss a method for generating a diffractive optical microrelief by plasmochemical etching with the use of a masking copper layer.

This work studies the propagation of middle IR laser radiation through an antireflection relief fabricated on the optical surface (made of silver halohenide). A new technology of microrelief fabrication that allows its antireflection properties to be enhanced is proposed.

The first results on the use of the hot stamping technique for fabricating a diffraction grating on the end face of the polycrystalline IR fibers (PIR-fibers) were reported in before. This paper presents a continuation of the research in this direction. In particular, we look into the possibility of using the hot stamping technique for fabricating antireflection subwavelength structures on the end faces of the silver halide PIR-fibers.

We derive what we believe to be new analytical relations to describe the Fraunhofer diffraction of the finite-radius plane wave by a helical axicon (HA) and a spiral phase plate (SPP). The solutions are deduced in the form of a series of the Bessel functions for the HA and a finite sum of the Bessel functions for the SPP. The solution for the HA changes to that for the SPP if the axicon parameter is set equal to zero. We also derive what we believe to be new analytical relations to describe the Fresnel and Fraunhofer diffraction of the Gaussian beam by a HA are derived. The solutions are deduced in the form of a series of the hypergeometric functions. We have fabricated by photolithography a binary diffractive optical element (a HA with number n=10) able to produce in the focal plane of a spherical lens an optical vortex, which was then used to perform rotation of several polystyrene beads of diameter 5 microm.

A technology for fabricating a diffractive microrelief on an end face of a polycrystalline IR fiber (PIR-fiber) is studied. We discuss how fabrication imperfections of a beam-splitter implemented on the fiber’s output end face could affect the specified intensity distribution of diffraction orders. Recommendations for improving the characteristics of the microrelief to manufacture are worked out.