scholarly journals Inverse-designed single-mode and multi-mode nanophotonic waveguide switches based on hybrid silicon-Ge2Sb2Te5 platform

2021 ◽  
pp. 104384
Author(s):  
Hansi Ma ◽  
Junbo Yang ◽  
Jie Huang ◽  
Zhaojian Zhang ◽  
Kaiwang Zhang
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Georg Rademacher ◽  
Benjamin J. Puttnam ◽  
Ruben S. Luís ◽  
Tobias A. Eriksson ◽  
Nicolas K. Fontaine ◽  
...  

AbstractData rates in optical fiber networks have increased exponentially over the past decades and core-networks are expected to operate in the peta-bit-per-second regime by 2030. As current single-mode fiber-based transmission systems are reaching their capacity limits, space-division multiplexing has been investigated as a means to increase the per-fiber capacity. Of all space-division multiplexing fibers proposed to date, multi-mode fibers have the highest spatial channel density, as signals traveling in orthogonal fiber modes share the same fiber-core. By combining a high mode-count multi-mode fiber with wideband wavelength-division multiplexing, we report a peta-bit-per-second class transmission demonstration in multi-mode fibers. This was enabled by combining three key technologies: a wideband optical comb-based transmitter to generate highly spectral efficient 64-quadrature-amplitude modulated signals between 1528 nm and 1610 nm wavelength, a broadband mode-multiplexer, based on multi-plane light conversion, and a 15-mode multi-mode fiber with optimized transmission characteristics for wideband operation.


Nanophotonics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 1265-1272
Author(s):  
Mengyuan Ye ◽  
Chunlei Sun ◽  
Yu Yu ◽  
Yunhong Ding ◽  
Xinliang Zhang

Abstract Ring resonator is an essential element in silicon integrated circuit, it is widely used as filter, wavelength multiplexer and switch in single-mode operation regime. As the rapid development of mode division multiplexing (MDM) technique, ring resonator that can process multi-mode signals simultaneously and uniformly is highly desired. However, the severe modal dispersion makes identical transmission for different modes very hard. In this paper, by breaking through the limitation of conventional multi-mode manipulation design with evanescent coupling or mode interference, we propose and demonstrate a multi-mode ring resonator (MMRR) inspired by the free space geometric optics. Arbitrary number of supporting modes can be achieved by simply widening the waveguide width. For proof-of-concept demonstration, an MMRR supporting four modes is fabricated with uniform transmittance. Furthermore, architecture of cascaded four MMRRs are also demonstrated experimentally.


2010 ◽  
Vol 22 (6) ◽  
pp. 1229-1233
Author(s):  
葛廷武 Ge Tingwu ◽  
陆丹 Lu Dan ◽  
伍剑 Wu Jian ◽  
徐坤 Xu Kun ◽  
林金桐 Lin Jintong
Keyword(s):  

Author(s):  
Andrea Alberti ◽  
Alessandro Munafò ◽  
Carlos Pantano ◽  
Jonathan Freund ◽  
Marco Panesi
Keyword(s):  

Author(s):  
Mohammad I. Younis

We present analytical solutions of the electrostatically actuated initially deformed cantilever beam problem. We use a continuous Euler-Bernoulli beam model combined with a single-mode Galerkin approximation. We derive simple analytical expressions for two commonly observed deformed beams configurations: the curled and tilted configurations. The derived analytical formulas are validated by comparing their results to experimental data in the literature and numerical results of a multi-mode reduced order model. The derived expressions do not involve any complicated integrals or complex terms and can be conveniently used by designers for quick, yet accurate, estimations. The formulas are found to yield accurate results for most commonly encountered microbeams of initial tip deflections of few microns. For largely deformed beams, we found that these formulas yield less accurate results due to the limitations of the single-mode approximations they are based on. In such cases, multi-mode reduced order models need to be utilized.


2015 ◽  
Vol 11 (6) ◽  
pp. 434-437 ◽  
Author(s):  
Xing-hu Fu ◽  
Qin Liu ◽  
Yan-li Xiu ◽  
Hai-yang Xie ◽  
Chuan-qing Yang ◽  
...  

2020 ◽  
Vol 31 (9) ◽  
pp. 1220-1239
Author(s):  
Johan Frederik Toftekær ◽  
Jan Høgsberg

The effective vibration mitigation properties of piezoceramic patches with inductive-resistive shunts are investigated experimentally. A shunt tuning method is proposed, in which a consistent correction for the influence from residual vibration modes is included by an effective modal capacitance, evaluated from measured charge and voltage amplitudes in short- and open-circuit conditions, respectively. The robustness of the proposed method is verified experimentally for both a free beam and a free plate structure with four shunted piezoceramic patch pairs. A stable and fully passive inductor is produced by winding a copper wire around a magnetic core, which requires precise inductance tuning to determine the final number of turns. It is demonstrated that the effective modal capacitance interpolates consistently between the blocked and static capacitances, commonly used for single-mode tuning of piezoelectric inductive-resistive shunts. By imposing pseudo-random vibrations, the piezoelectric current and voltage signals are measured and evaluated by their frequency response functions. Spectrum peak values determine the apparent short-circuit charge to open-circuit voltage ratio for each shunt, which directly determines the shunt components by explicit tuning formulas. Good correlation between numerical and experimental results are obtained for the free beam, while for the free plate experiment effective multi-mode shunt tuning is obtained by a modified effective electromechanical coupling coefficient.


2019 ◽  
Vol 33 (32) ◽  
pp. 1950403
Author(s):  
Fengxiang Guo ◽  
Hui Guo ◽  
Pei Sun ◽  
Tao Yuan ◽  
Yansong Wang

Viscoelastic materials can dissipate energy and hinder propagation for plane waves, which can adjust the band structures of phononic crystals (PCs). In this study, the wave propagation in a two-dimensional PC with a viscoelastic matrix is investigated. The Maxwell model is utilized to analyze the effect of material parameters on the frequency dependence of viscoelasticity. Material parameters include the relaxation time, the initial value and the final value of the shear modulus. Band structures of viscoelastic phononic crystals (VPCs) are solved by combining the plane wave expansion method and iterative algorithm based on Bloch theory. The effects of the viscoelasticity on the band structures are studied using the single-mode and multi-mode Maxwell models. Results reveal that the viscoelasticity of the materials not only extends the band gaps but also shifts the band gaps to lower frequencies. Furthermore, the viscoelasticity simulated by the multi-mode model can precisely adjust anyone of the band gaps of VPCs separately. Results provide insights into the design and applications of VPCs.


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