A compact design of a balanced 1×4 optical power splitter based on silicon on insulator slot waveguides

In this paper, a compact design of a balanced 1×4 optical power splitter based on coupled mode theory (CMT) is presented. The design consists of seven vertically slotted waveguides based on the silicon-on-insulator platform. The 1×4 OPS is modelled using commercial finite element method (FEM) simulation tool COMSOL Multiphysics 5.1. The optimized OPS is capable of working across the whole C-band with maximum ~39 % of power decay in the wavelength range 1530 – 1565 nm.This work was partially financially supported by Ministry of Education and Science of Russian Federation, Russian Foundation for Basic Research (RFBR) (16-47-630677, 16-29-11744) and by the Federal Agency for Scientific Organizations (agreement No. 007-G7/C3363/26)

Asymmetric apodization for the comma aberrated point spread function

This paper deals with the study of light flux distributions in the point spread function formed by an optical system with a one-dimensional aperture under the influence of the coma aberration. The traditional design of an asymmetric optical filter improves the resolution of a diffraction-limited optical imaging system. In this approach we explore the control of monochromatic aberrations through pupil engineering with asymmetric apodization. This technique employs the amplitude and phase apodization for the mitigation of the effects of third-order aberrations on the diffracted image. On introducing the coma wave aberration effect, the central peak intensity in the field of diffraction is a function of the edge strips width and the amplitude apodization parameter of a one-dimensional pupil filter, whereas the magnitude of the reduction of optical side-lobes is a function of the degree of phase apodization at the periphery of the aperture. The analytically computed results are illustrated graphically in terms of point spread function curves under various considerations of the coma aberrations and a different degree of amplitude and phase apodization. Hence, for the optimum values of apodization, the axial resolution has been analyzed using well-defined quality criteria.This work was partially financially supported by Ministry of Education and Science of Russian Federation and Russian Foundation for Basic Research (RFBR) (16-29-11698, 16-29-11744)

Design and simulation of a SOI based mems differential accelerometer

In this paper, the design and analysis of a differential MEMS capacitive accelerometer is presented. The device is designed to be compatible for SOI based fabrication process. The outstanding mechanical and electrical properties of silicon on insulator (SOI) wafers make it popular for high-performance MEMS sensors such as accelerometers. The operating range of the designed device is 0-10g with its sense axis in the in-plane direction. The movable comb fingers attached to the proof mass form capacitors with the fixed electrode fingers. The movable and fixed fingers are spaced with unequal gaps to form the differential capacitive sensing configuration. The base capacitance of this configuration is about 0.77pF and the sensitivity in response to acceleration input is about 0.776 fF/g. The resonance frequency of the structure in the sensing mode is found to be 7.138 kHz.The work was partially funded by the Russian Federation Ministry of Education and Science

Focusing of light beams by the phase apodization pupil

We investigated reduction of the size of the illuminated beam in the focal region produced by the optical systems of NA = 0.99 has been. The intensity distributions of polarized light field in the focal volume for the phase apodization pupil have been discussed. The circular pupil in different phase apodization situations can be employed to control the field components in the resultant intensity distribution. We show that both axial and transverse resolution improvement in the focal distribution is possible by applying proper phase engineering in the annulus of the pupil function.This work was financially supported by the Russian Foundation for Basic Research (grants 16-07-00825, 16-29-11698) in part of vector computer calculations and by the Ministry of Science and Higher Education within the State assignment FSRC “Crystallography and Photonics” RAS No 007-GZ/Ch3363/26 in part of scalar computer calculations