A simple and low-crosstalk 1 × 4 silicon mode (de)multiplexer based on multimode grating-assisted-couplers is proposed. Mode transitions can be flexibly controlled by designing the grating period at phase-matching condition. Due to contra-directional coupling, precise control of coupling strength length are not needed in system. Calculation results show that insertion loss 3 dB bandwidths device 0.2 3.7 nm, 0.34 7.6 0.21 11.8 nm for channels which (de)multiplex 1st, 2nd, 3rd modes bus...

In this paper, a resonant system is demonstrated on silicon-on-insulator wafer to achieve tunable Fano resonances. system, the resonance originates from interference of two beams in microring resonator. The shapes resonances are through controlling phase difference beams. Both large slope and high extinction ratio (ER) obtained when 0.5π or 1.5π. Experimental results show that with steep ER over 20 dB achieved whole free spectral range by microheaters meet condition.

A silicon photonic wire filter based on an asymmetric sidewall Bragg grating in a multimode silicon-on-insulator strip waveguide is demonstrated. The operating principle the contra-directional coupling between transverse electric fundamental (TE0) and first-order (TE1) modes, which enabled by spatially periodic refractive-index perturbations. An Y-junction cascaded at input port of so as to drop reflection. Compared with conventional grating-based filters, this device eliminates back...

Compact polarization beam splitter (PBS) based on grating-assisted couplers is proposed by utilizing contra-directional coupling between two corrugated strip waveguides. The co-directional in the device greatly suppressed designed asymmetric structure. phase matching condition only satisfied for TE at central wavelength of 1550 nm a spatially periodic refractive-index perturbation. Due to coupling, breaks limit precise control strength and length. simulation results show that presented PBS,...

A lateral-apodized add–drop filter is demonstrated in a multimode asymmetric waveguide Bragg grating. This design utilizes two individual superposed gratings with the same sidewall corrugation depth. The strong side lobes of grating are efficiently suppressed by mapping target apodization profile into lateral shifts between periods gratings. Compared other apodized technology, this device easier to be realized. Experimental results show that side-lobes suppression ratio can reach 18.5 dB,...

We design and fabricate a wavelength-selective nonblocking 4×4 silicon optical router based on microring resonator for use in future integrated photonic interconnection networks. successfully demonstrate 12 possible I/O routing paths present 13 operating states, including four broadcasting with worst-case extinction ratio cross talk of 21.05 −21.56 dB, respectively. Thermal tuning is employed to compensate the resonance shift resonators caused by fabrication errors adjust match International...

A silicon photonic add-drop filter is demonstrated with sidewall Bragg gratings in a multimode strip waveguide. The operating principle based on the contradirectional coupling between TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> mode and different higher-order modes inside waveguide, which depends symmetry property of periodic refractive-index perturbations. In order to relax fabrication tolerance, pair adiabatic couplers used...

We propose and demonstrate experimentally an ultracompact resonant system exhibiting sharp asymmetric Fano-resonance, in which a tiny photonic crystal nanobeam cavity is laterally coupled to waveguide Fabry-Perot resonator. Under the presence of intrinsic loss, we find that produces sharper higher extinction ratio Fano resonance spectra only if appropriate phase selected. The whole device (∼6 μm2) implemented on silicon insulator platform, observe steep-slope with 7.3 dB, slope above 5...

A broadband tunable silicon filter has been demonstrated on silicon-on-insulator platform. The device is based the loop of multimode anti-symmetric waveguide Bragg grating. wide bandwidth tunability about 1.455 THz (0.117-1.572 THz) achieved. device, functions like a ring, can realize drop port and through port. And, its feature simultaneous wavelength tuning no free space ranges limitation. high out-of-band contrast 30 dB achieved with 1.572 (Δλ = 13 nm). 18 at minimum 0.117 1.0

We demonstrate a thermally tunable four-channel add/drop demultiplexer based on silicon grating-assisted contra-directional couplers (contra-DCs) for 200 GHz dense wavelength division multiplexing (DWDM) systems. In order to obtain the narrow bandwidth and rapid roll-off necessary DWDM, every channel is filtered dually by two identical contra-DCs cascaded in parallel. addition, phase apodization technique utilized suppress sidelobes. With these special designs, passbands of four drop ports...

We demonstrate a silicon <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\times 64$ </tex-math></inline-formula> optical phased array by using carrier-depletion-based phase shifters. The 5-mm-long shifter exhibits an electro-optic bandwidth of 700 MHz, modulation efficiency 2.3 V.cm, and ultra-low power consumption < 0.45 nW/ notation="LaTeX">$\boldsymbol {\pi }$ . A steering range ±18° is realized in the...

A multimode fiber-loop ring-down spectroscopy combined with a fiber mode converter for strain measurement is presented. The bending loss theory in fibers used the explanation of induced ring down cavity mechanism, which agrees well experimental results. With this technique, achieved time domain by measuring time. sensing system demonstrated good linear response, stability and high resolution as small 0.33 muepsiv over rang 800 muepsiv.

Ultracompact channel add-drop filter utilizing a single nanobeam photonic crystal cavity is analyzed, designed, and demonstrated. Anti-symmetric multimode periodic waveguide structure employed to implement mode conversion thus produce degenerate resonant states in the involved cavity. Theoretical analysis results indicate that inter-modal coefficient waveguide-cavity coupling have significant effects on lineshape of filter. By carefully engineering its side-coupled configuration, we...

Asymmetric Y-junctions, compared with mode coupling-based devices, possess considerably smaller wavelength dependence and thus are more promising for ultra-broadband (de)multiplexing in integrated optics. However, these devices also feature relatively high crosstalk insertion loss. Here, we show that the loss of an asymmetric Y-junction can be significantly reduced by optimizing waveguide shape using adjoint-based inverse design. Based on such inverse-designed realize ultra-compact,...

Reconfigurable optical add-drop filters in future intelligent and software controllable wavelength division multiplexing networks should support hitless switching gridless bandwidth tuning. The implies that the central of one channel can be shifted without disturbing data transmissions other channels, while tuning means filter adjusted continuously. Despite a lot efforts, very few integrated simultaneously bandwidth. In this work, we demonstrate with tunability on silicon-on-insulator (SOI)...

Antisymmetric multimode nanobeam photonic crystal cavities (AM-NPCs) are proposed and demonstrated in this paper. Due to transverse symmetry-breaking of the antisymmetric periodic waveguide, anti-crossing fundamental mode 1st-order is realized confirmed by band structure calculation. Two-mode filtering reflection-free cavity filters based on characteristic demonstrated. Experimental results silicon-on-insulator platform shows that broadband (> 100 nm) reflection suppression (< -10 dB) high-Q...

A narrow-band add-drop filter based on an anti-symmetric cladding-modulated multimode Bragg grating (CMMBG) is demonstrated the silicon-on-insulator (SOI) platform. The CMMBG implemented by using periodic placements of silicon cubes along a waveguide. coupling strength varied changing distance between and An unlimited free-spectral range (FSR) weak strengths for TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> -TE...

We demonstrate the design, fabrication, and characterization of side-coupled airmode nanobeam photonic crystal cavities in silicon-on-insulator platform. Results show that repeatable devices achieve similar high loaded quality factors (>10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> ) large optical energy ratio low refractive region. The unload Q-factors fabricated are estimated to exceed 10...

Abstract A fiber‐loop ring‐down spectroscopy based on multimode fiber is proposed for pressure measurement. It has been found that the sensor higher sensitivity and larger dynamic range up to 6.2 × 10 7 Pa compared single mode counterpart. Good stability repeatability of are also demonstrated. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1698–1700, 2007; Published online in InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22553

An integrated-optics, flat-top drop-filter with low excess loss, and high sidelobe suppression ratio (SLSR), is demonstrated. The filter based on apodized multimode waveguide Bragg grating (AMWBG) developed a silicon-on-insulator (SOI) platform. Antisymmetric periodic refractive-index perturbations are imposed both sides of the to couple light contra-directionally between fundamental (TE0) first-order transverse electric modes (TE1). To achieve Gaussian apodization profile,...

Single silicon nanobeam photonic crystal cavity based sensors are systematically analyzed and designed. By using perturbation theory numerical simulations, both dielectric-mode air-mode cavities extensively investigated in terms of sensitivity (S), figure merit (FOM), detection limit (DL), footprint size, coupling scheme. The analytical study reveals a 1176 nm/RIU maximum 5070 for sensors, due to the absorption light near 1550 nm wavelength. when water is used as carrier fluid. Design high...

We demonstrate flat-top, sharp-edge, silicon add-drop filters using apodized grating-assisted contradirectional couplers (contra-DCs). Periodic sidewall corrugations are imposed on both sides of two asymmetric strip waveguides for coupling between the first TE supermodes a two-waveguide system. Gaussian apodization is applied to suppress sidelobes. By laterally shifting positions waveguide Bragg gratings in complementary manner, which called lateral-misalignment modulation, our devices avoid...

We propose an ultracompact channel drop filter (CDF) based on photonic crystal nanobeam cavities. The conditions for implementing such ideal CDF are derived from the temporal coupled-mode equations governing operation of CDF. By considering intercoupling two involved cavities, some ambiguities previous equivalent circuit model analysis cleared up. Practical configurations silicon-on-insulator (SOI) proposed suggested with a typical length less than 15 μm. Finite difference time domain (FDTD)...

This investigation elucidates the influence of nitrogen doping (N-doping) on magnetoresistance (MR) characteristics graphdiyne (GDY) by methodically adjusting levels N-doping. Through exhaustive experimental analyses, encompassing SEM, XPS, and magneto-transport measurements, we demonstrate that N-doping markedly augments carrier concentration, thereby inducing distinct MR behaviors. Specifically, N

We demonstrate a multimode fiber loop ring down spectroscopy for pressure measurement with higher sensitivity over larger dynamic range of compared single mode counterpart.