Nikolai Petrov
Scientific and Technological Center of Unique Instrumentation of Russian Academy of Sciences
Nikolai Petrov, Chief Researcher
He received M.S. degree in theoretical physics from Kazan State University of Russia, PhD degree in physical and quantum electronics from General Physics Institute of Russian Academy of Sciences, and D.Sc. degree from IZMIRAN in 1979, 1986, and 1997, respectively. During 1993-1994, he was awarded a Royal Society Postdoctoral Fellowship at Cardiff University, UK. During 2000-2015, he worked for the R&D Centers of Samsung Electronics, LG Electronics and Huawei in the areas of optical recording, micro- and nano-scale engineering, display and image processing. His research interests: diffraction optics, electrodynamics of inhomogeneous media, plasma physics, acousto-optics, nanophotonics.
Micro-optical elements are widely used in modern optical systems, such as light homogenizers, LEDs, displays, illumination systems, etc. Other application is the 3D image systems. Diffractive elements are the most powerful... [ view full abstract ]
Micro-optical elements are widely used in modern optical systems, such as light homogenizers, LEDs, displays, illumination systems, etc. Other application is the 3D image systems. Diffractive elements are the most powerful method for beam shaping, however, there are issues including the limitation to monochromatic illumination, limited divergence angles, and zero order, typically due to fabrication errors. A new class of beam shapers such as periodic microlens arrays has high transmission efficiency, controlled angular distribution and homogenized light [1].
In this paper, the analysis of the influence of the parameters of radiation source (wavelength, wavefront curvature, coherence, polarization) and micro-lens array (sag, lens size, refractive index, etc.) on the parameters of a diffracted beam is presented. The method combining wave propagation and ray-tracing procedures is proposed for the analysis of partially coherent light beams diffracted by micro-lens structures. The beam field at complicated surfaces is expanded into coherent states [2], representing elementary Gaussian beams with axis displacement and tilt angle.
Optical transmission efficiency depends on the polarization of incident light, and on the lens surface orientation relative to the light source. Influence of the randomization of the parameters of MLA on the intensity distribution is investigated.
In Fig. 1 the intensity distributions and radiation patterns for coherent (a, c) and low-coherent (b, d) sources are presented.
It is shown that it is possible to split the incident beam into a set of identical focused beams located at the same distances from each other (Fig. 2). In Fig. 3 the formation of independent beams during the propagation of light behind the MLA screen is shown. It is followed from the simulations that each of the beams propagate independently. The angular separation of the beams depends on the aspect ratio of MLA. For the considered values of RL = 10 μm and Rsc = 3 μm the angular separation between spots is equal to 16.23 mrad.
Acknowledgement: The financial support by the Russian Science Foundation (project No. 17-19-01461) is highly appreciated.
References
[1] T.R.M. Sales, Opt. Eng. 42, 3084-3085 (2003).
[2] N.I. Petrov, G.N. Petrova, Optics Express 25, No. 19, 22545-22564 (2017).
Optical properties of nanostructures , Advanced imaging for photonic materials
