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Starting from the rigorous excitation equation, the propagation of waves through a 2D waveguide with the periodically corrugated finite-length insert is examined in detail. The corrugation profile is chosen to obey the property that its…

Mesoscale and Nanoscale Physics · Physics 2013-06-20 V. O. Goryashko , Yu. V. Tarasov , L. D. Shostenko

To optimize the coupling efficiency of grating couplers, we extend an analytical model for the design of apodized grating couplers, taking into account the constraints on the upper and lower bounds of the scattering strength as determined…

Optics · Physics 2020-08-26 Zhexin Zhao , Shanhui Fan

Mode tapering, or the gradual manipulation of the size of some mode, is a requirement for any system that aims to efficiently interface two or more subsystems of different mode sizes. While high efficiency tapers have been demonstrated,…

Silicon photonic wavefront phase-tilt sensors for wavefront monitoring using surface coupling grating arrays are demonstrated. The first design employs the intrinsic angle dependence of the grating coupling efficiency to determine local…

Using 10 monopole antennas reaching into a rectangular multi mode waveguide we shape the incident wave to create specific transport even after scattering events. Each antenna is attached to an IQ-Modulator, which allows the adjustment of…

Optics · Physics 2020-09-16 Julian Böhm , Ulrich Kuhl

Ability to selectively enhance the amplitude and maintain high coherence of the supercontinuum signal with long pulses is gaining significance. In this work an extra degree of freedom afforded by varying the dispersion profile of a…

We report the spectral features of a phase-shifted parity and time ($\mathcal{PT}$)-symmetric fiber Bragg grating (PPTFBG) and demonstrate its functionality as a demultiplexer in the unbroken $\mathcal{PT}$-symmetric regime. The length of…

Optics · Physics 2020-08-05 S. Vignesh Raja , A. Govindarajan , A. Mahalingam , M. Lakshmanan

It is known that an acoustic wave incident on an infinite array of aligned rectangular blocks of a different acoustic material exhibits total transmission if certain conditions are met [1] which relate the unique "intromission" angle of…

Computational Physics · Physics 2017-08-23 Andrew N. Norris , Xiaoshi Su

Modal phase matching (MPM) is a widely used phase matching technique in Al$_x$Ga$_{1-x}$As and other $\chi^{(2)}$ nonlinear waveguides for efficient wavelength conversions. The use of a non-fundamental spatial mode compensates the material…

Optics · Physics 2021-12-30 Dongpeng Kang , Weiqi Zhang , Amr S. Helmy , Siyuan Yu , Liying Tan , Jing Ma

We report that metamaterial-inspired one-dimensional gratings (or metagratings) can be used to control nonpropagating diffraction orders as well as propagating ones. By accurate engineering of the near field, it becomes possible to satisfy…

Applied Physics · Physics 2019-03-06 Vladislav Popov , Fabrice Boust , Shah Nawaz Burokur

We propose the use of interleaved graphene sections on top of a silicon waveguide to implement tunable Bragg gratings. The filter central wavelength and bandwidth can be controlled changing the chemical potential of the graphene sections.…

Optics · Physics 2015-06-18 Jose Capmany , David Domenech , Pascual Munoz

We report a new gateway to enhance the sponatnesous emission rate of single quantum emitters by introducing a cavity in tilted nanofiber Bragg grating (TNFBG). We found that light emitter's coupling efficiency into the tilted grating…

Optics · Physics 2020-12-17 Subrat Sahu , Rajan Jha

Digital filters with variable bandwidth can be used for a variety of applications. Arbitrary change in the bandwidth of a digital Finite Impulse Response (FIR) filter can be acquired using sampling rate converters. In this paper, a sampling…

Signal Processing · Electrical Eng. & Systems 2021-09-27 Sushmitha Sajeevu , V. Sakthivel

Grating magneto-optical traps are an enabling quantum technology for portable metrological devices with ultracold atoms. However, beam diffraction efficiency and angle are affected by wavelength, creating a single-optic design challenge for…

Exploring the use of single-mode fibers (SMFs) in high precision Doppler spectrometers has become increasingly attractive since the advent of diffraction-limited adaptive optics systems on large-aperture telescopes. Spectrometers fed with…

Instrumentation and Methods for Astrophysics · Physics 2015-12-02 Samuel Halverson , Arpita Roy , Suvrath Mahadevan , Christian Schwab

This work presents a theoretical investigation of an active photonic grating of the parity-time (PT) symmetric architecture. The analytical study of the free-space mode propagation from the grating structure indicates the unique bifurcation…

Optics · Physics 2021-12-21 Tahere Hemati , Yi Zou , Binbin Weng

Controlling the modal content coupled into an optical fiber can be desireable in many situations, e.g. for adjusting the sensitivity of the guided field distribution to external perturbations. For this purpose we used a monolithic setup of…

Optical communication systems, operating in C-band, are reaching their theoretically achievable capacity limits. An attractive and economically viable solution to satisfy the future data rate demands is to employ the transmission across the…

Efficient transmission of elastic waves across interfaces is central to several applications, including medical imaging, seismic isolation, and transducer design. Interfaces with abrupt changes in the material properties significantly…

Optics · Physics 2026-02-25 Jagannadh Boddapati , Jihoon Ahn , Alexander C Ogren , Chiara Daraio

In this paper we report phase modulation obtained by inducing a capacitive charge on graphene layers embedded in the core of a waveguide. There is a biasing regime in which graphene absorption is negligible but large index variations can be…

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