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Related papers: Low-Loss THz Waveguide Bragg Grating using a Two-W…

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We experimentally demonstrate a broadband, fabrication tolerant, CMOS compatible compact silicon waveguide taper (34.2 um) in silicon-on-insulator wire waveguides. The taper works on multi-mode interference along the length of the taper. A…

Applied Physics · Physics 2020-01-01 Purnima Sethi , Shankar Kumar Selvaraja

In this brief, we present a low-loss mechanically reconfigurable phase shifter implemented in gap-waveguide technology for mm-wave frequencies. The proposed design gives a practical implementation of tuning elements inside the waveguide…

Signal Processing · Electrical Eng. & Systems 2021-01-06 Á. Palomares-Caballero , A. Alex-Amor , P. Escobedo , J. Valenzuela-Valdés , P. Padilla

The 1-10 terahertz (THz) spectral window is emerging as a key region for plenty of applications, requiring not yet available continuous-wave room-temperature THz spectrometers with high spectral purity and ultra-broad tunability. In this…

Novel hollow-core THz waveguides featuring hyperuniform disordered reflectors are proposed, fabricated, and characterized. The reflector comprise aperiodically positioned dielectric cylinders connected with dielectric bridges. The proposed…

In this paper we show how transmission metallic gratings with very narrow and deep enough slits can exhibit transmission resonances for wavelengths larger than the period of the grating. By using a transfer matrix formalism and a…

Materials Science · Physics 2009-10-31 J. A. Porto , F. J. Garcia-Vidal , J. B. Pendry

Traveling wave parametric amplifiers (TWPAs) have recently emerged as essential tools for broadband near quantum-limited amplification. However, their use to generate microwave quantum states still misses an experimental demonstration. In…

We present a method to analyse the coupling of lateral displacements in nanoscale structures, in particular waveguide grating mirrors (WGM), into the phase of a reflected Gaussian beam using a finite-difference time-domain simulation. Such…

Carbon nanomaterials such as carbon nanotubes and graphene have proved to be efficient building blocks for active optoelectronic devices. Especially, the exotic properties of crystalline graphene, such as a linear/gapless energy dispersion,…

The efficient modulation and control of ultrafast signals on-chip is of central importance in terahertz (THz) communications and a promising route toward sub-diffraction limit THz spectroscopy. Two-dimensional (2D) materials may provide a…

We report a highly efficient tunable THz reflector in graphene. By applying a small gate voltage (up to 3 V), the reflectance of graphene is modulated from a minimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures at…

Mesoscale and Nanoscale Physics · Physics 2017-03-08 Yang Wu , Xuepeng Qiu , Hongwei Liu , Jingbo Liu , Yuanfu Chen , Lin Ke , Hyunsoo Yang

In this Letter, we study the transmission response of microwaves through two identical metallic plates machined with ultranarrow slit arrays. The measured and calculated transmission spectra consistently display a striking transmission peak…

Optics · Physics 2015-06-11 Chunyin Qiu , Sucheng Li , Ruirui Chen , Bo Hou , Feng Li , Zhengyou Liu

Acquiring full control over a large number of diffraction orders can be strongly attractive in the case of realizing multifunctional devices such as multichannel reflectors. Recently, the concept of metagrating has been introduced which…

Applied Physics · Physics 2020-03-18 Sahar Behroozinia , Hamid Rajabalipanah , Ali Abdolali

We demonstrated an ultra-broadband, polarization-insensitive and wide-angle metamaterial absorber for terahertz (THz) frequencies using arrays of truncated pyramid unit structure made of metal-dielectric multilayer composite. In our design…

Optics · Physics 2014-06-02 Jianfei Zhu , Zhaofeng Ma , Wujiong Sun , Fei Ding , Qiong He , Lei Zhou , Yungui Ma

We realize a fiber Bragg grating InGaN based laser diode emitting at 400 nm and demonstrate its high coherency. Thanks to the fabrication of a narrow band fiber Bragg grating in the near-UV, we can reach single-mode and single-frequency…

Metallic gratings can be used as infrared filters, but their performance is often limited by bandwidth restrictions due to metallic losses. In this work, we propose a metallic groove-slit-groove (GSG) structure that overcomes these…

Optics · Physics 2024-12-02 Denis Langevin , Julien Jaeck , Riad Haïdar , Patrick Bouchon

Fiber bragg gratings (FBG) has wide variety of applications in sensor and laser devices. In this work, we have fabricated FBG using point by point (PbP) technique utilizing fs laser. FBGs spectral characteristics were explored through the…

Optics · Physics 2022-10-14 Abu Farzan Mitul , Bohan Zhou , Huiyu Zhao , Ming Han

We report a terahertz optical modulator consisting of randomly stacked trilayer graphene (TLG) deposited on an oxidized silicon substrate by means of THz- Time Domain Spectroscopy (THz-TDS). Here, the gate tuning of the Fermi level of the…

Materials Science · Physics 2017-01-31 Ioannis Chatzakis , Zhen Li , Alex Benderskii , Stephen B. Cronin

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

Semiconductor quantum dots embedded in circular Bragg gratings (CBGs) are among the most efficient integrated single-photon sources. However, the fully etched rings of conventional CBGs restrict the implementation of charge and Stark tuning…

We have developed theory for the interaction of THz radiation with a sub-wavelength metallic grating. The structure of electric fields of the electromagnetic wave under the metallic grating has been studied in the near-field zone. Spatial…

Mesoscale and Nanoscale Physics · Physics 2012-11-06 Yu. M. Lyaschuk , V. V. Korotyeyev