Преобразование мод в гибридных волноводных структурах на основе ниобата лития для согласования со стандартным одномодовым оптическим волокном

Topology of a hybrid waveguide device, which performs an effective transformation of a standard gradient titanium in-diffused waveguide mode to a hybrid waveguide mode, is considered. With its help a rather large optical mode with size optimal for coupling with standard single-mode fibers can be converted to a mode with a smaller size. Two the most perspective materials for hybrid waveguide fabrication were considered: silicon and titanium dioxide. The theoretical analysis has shown that transformation efficiency of more than 99% is achievable for waveguide devices based on titanium dioxide with contact lithography resolution.

Comparative Analysis of Compact Satellite Polarizers Based on a Guide with Diaphragms

In this article we carry out the comparative analysis of new compact satellite polarisers based on a square guide with diaphragms. The main electromagnetic parameters of the developed microwave guide devices with various amount of diaphragms were obtained within the satellite frequency interval from 10.7 GHz to 12.75 GHz. Waveguide polarization converters with different amount of diaphragms from 2 to 5 have been designed and optimized. The main parameters of the presented polarizer were calculated applying the numerical method of finite integration in the frequency domain. Optimization of the electromagnetic parameters of the developed waveguide devices was carried out using the software CST Microwave Studio. As a result, sizes of the device designs have been optimized for the provision of improved polarization and phase parameters. The performed analysis showed that a waveguide polarizer with five diaphragms has the best electromagnetic parameters. The developed compact polarizer with five diaphragms based on a square guide provides a minimum deviation of the output phase difference from 90 degrees and high level of isolation between linear polarization over the entire operating frequency range. Presented in the article compact waveguide polarization converters can be applied in satellite systems, which require efficient polarization separation of signals.

From Classical to Quantum Nonlinear Photonic Mixers on Silicon Microchips (Project Report 1201308-Y4)

The main goal of this NSF-funded project [1201308 - Year 4] is to develop an integrated photonics devices based on silicon photonics which can be used for compact and efficient nonlinear classical and quantum photonics. We demonstrated tunable photon-pair generation at room temperature from a high-Q Si microring resonator and coupled-resonator optical waveguide devices.

Breaking reciprocity and preserving-frequency using linear acoustic metamaterials

In this paper, we introduce a linear waveguide implemented by cascading acoustic black holes (ABHs). The asymmetric wave propagation, up to 46 dB, is observed and verified in simulation and experiment. It is shown that, in comparison with the previous nonlinear acoustic diodes, our waveguide can rectify the sound without shifting the impinging sound frequency. The device is simple and easy-to-fabricate without using complex nonlinear materials and space–time modulation. This feature could open a new route for designing acoustic waveguide devices that preserve the key information.