Power Splitter Research Articles

Design of GaSb-based monolithic passive photonic devices at wavelengths above 2 µm

In this paper, we report, for the first time, a theoretical study on passive photonic devices including optical power splitters/combiners and grating couplers (GCs) operating at non-telecom wavelengths above 2 µm in a monolithic GaSb platform. Passive components were designed to operate, in particular, at around 2.6 µm for monolithic integration with active photonic devices on the III–V gallium antimonide material platform. The three popular types of splitters/combiners such as directional couplers, multimode interferometer-, and Y-branch-couplers were theoretically investigated. Based on our optimized design and rigorous analysis, fabrication-compatible 1 × 2 optical power splitters with less than 0.12 dB excess losses, large spectral bandwidth, and a 50:50 splitting ratio are achieved. For fiber-to-chip coupling, we also report the design of GCs with an outcoupling efficiency of ∼29% at 2.56 μm and a 3 dB bandwidth of 80 nm. The results represent a significant step towards developing a complete functional photonic integrated circuits at mid-wave infrared wavelengths.

Design, fabrication and characterization of a three dimensions power splitter in written waveguides in Lithium Niobate by fs laser

Design, fabrication and characterization of a three dimensions power splitter in written waveguides in Lithium Niobate by fs laser

Quadrature Wilkinson power divider using cross-type short-circuited shunt stub for good amplitude and phase balance

This paper introduces a new design of a quadrature 3-dB power splitter using a quadrature Wilkinson power divider and a cross-type short-circuited shunt stub for printed circuit board (PCB) circuit design. For 3-dB power splitting and a relative 90° phase difference, several types of quadrature 3-dB power splitters are commonly used in RF and microwave applications, including Lange coupler, directional coupler, branch-line coupler, and quadrature Wilkinson power dividers. Among them, quadrature Wilkinson power dividers often utilize a Schiffman phase shifter and λ/4 short-circuited shunt stubs for compensation circuit.In this paper, the aforementioned schemes have been evaluated by image rejection ratio (IRR) bandwidth (BW) related to amplitude and phase imbalance property. The new design of the quadrature Wilkinson power divider adopting the proposed cross-type short-circuited shunt stub offers superior −25-dB IRR BW compared with other quadrature 3-dB power splitters in PCB fabrication. In measurement, the proposed quadrature Wilkinson power divider provided a −25-dB IRR BW of 3.50 GHz, operating at a center frequency of 9.5 GHz. The designed power splitter offered an operating frequency of 2.64 GHz, satisfying −25-dB IRR BW, 10-dB impedance BWs, and 20-dB isolation BW.

Controllable hybrid plasmonic integrated circuit

In this paper, a controllable hybrid plasmonic integrated circuit (CHPIC) composed of hybrid plasmonic waveguide (HPW)-based rhombic nano-antenna, polarization beam splitter, coupler, filter, and sensor has been designed and investigated for the first time. In order to control the power into a corresponding input port, a graphene-based 1 × 3 power splitter with switchable output has been exploited. The functionality of each device has been studied comprehensively based on the finite element method and the advantages over state-of-the-art have been compared. Moreover, the effect of connection of CHPIC to the photonic and plasmonic waveguides has been studied to exhibit the capability of variety excitation methods of the CHPIC. Furthermore, the performance of the proposed CHPIC connected to inter/intra wireless transmission links has been investigated. The wireless transmission link consists of two HPW-based nano-antennas as transmitter and receiver with the maximum gain and directivity of 10 dB and 10.2 dBi, respectively, at 193.5 THz. The suggested CHPIC can be used for applications such as optical wireless communication and inter/intra-chip optical interconnects.

Online Learning for Joint Energy Harvesting and Information Decoding Optimization in IoT-Enabled Smart City

In this study, we first present a framework that jointly optimize energy harvesting and information decoding for Internet of Things (IoT) devices, which are capable of simultaneous wireless information and power reception, in a smarty city. In particular, a generalized power splitting receiver for IoT devices is designed, where each antenna in the receiver has an independent power splitter, unlike the existing works in which only one power splitter is employed regardless of the number of antennas in the receiver. Such a receiver design can provide a great degree of freedom to improve the network performance. Based on the presented framework, for each IoT device, we formulate an optimization problem whose objective is to maximize the harvested energy of each IoT device while satisfying its data rate requirement. To solve this problem, we propose a double-deep deterministic policy gradient based online learning algorithm which enables each IoT device to jointly determine receive beamforming and power splitting ratio vectors in real-time. Further, each IoT device can implement the proposed algorithm in a distributed manner using only its local channel state information. As such, cooperation and information exchange among the base stations and IoT devices are not necessary when performing the proposed algorithm at IoT devices. The extensive simulation results show the validity of the proposed algorithm.

Precise asymmetric power‐splitter (1.7:1) by using nano‐pixel waveguide

AbstractPower‐splitter is one of the fundamental elements for photonic integrated circuits. Y‐junction, multi‐mode‐interference (MMI), and directional coupler may have been widely used as power splitter; however, the design theory to realize precise asymmetric splitting ratio is not well established. In addition, the device length is relatively long and less robustness in general. To realize a power splitter with a desired splitting ratio, the authors used a nano‐pixel structure. Nano‐pixel structures consist of an array of pixels in which the rectangular waveguide region is divided into many nano‐scale regions. The implemented devices were realized in an area of 3.2 μm × 3.4 μm. The device exhibited precise asymmetric splitting of 1.7:1 successfully at 1550 nm.

A Compact Four-way Quadrature Power Splitter for 5G Low-band Applications

This article introduces an ultra-compact four-way quadrature power splitter (4W-QPS) based on a novel transmission-line compression technique called double-path zigzag microstrip line (DP-ZML). Detailed design techniques with modular approach are disclosed for the state-of-the-art 5G low-band applications. The theoretical predictions are verified with experimental results through a fabricated prototype that operates from 696.55 to 876.03 MHz with >15 dB return-losses and isolations, and 90°±4° quadrature phase between adjacent outputs. The compact size of this 4W-QPS is achieved at 0.21λg×0.21λg at a center frequency of 786 MHz.

Transport of a topologically protected photonic waveguide on-chip

We propose a design on integrated optical devices on-chip with an extra width degree of freedom by using a photonic crystal waveguide with Dirac points between two photonic crystals with opposite valley Chern numbers. With such an extra waveguide, we demonstrate numerically that the topologically protected photonic waveguide retains properties of valley-locking and immunity to defects. Due to the design flexibility of the width-tunable topologically protected photonic waveguide, many unique on-chip integrated devices have been proposed, such as energy concentrators with a concentration efficiency improvement of more than one order of magnitude, and a topological photonic power splitter with an arbitrary power splitting ratio. The topologically protected photonic waveguide with the width degree of freedom could be beneficial for scaling up photonic devices, and provides a flexible platform to implement integrated photonic networks on-chip.

A Topological Multichannel Add-Drop Filter Based on Gyromagnetic Photonic Crystals.

We theoretically proposed a topological multichannel add-drop filter (ADF) and studied its unique transmission properties. The multichannel ADF was composed of two one-way gyromagnetic photonic crystal (GPC) waveguides, a middle ordinary waveguide, and two square resonators sandwiched between them, which can be regarded as two paralleling four-port nonreciprocal filters. The two square resonators were applied with opposite external magnetic fields (EMFs) to support one-way states propagating clockwise and counterclockwise, respectively. On the basis of the fact that the resonant frequencies can be tuned by the EMFs applied to the square resonators, when the intensities of EMFs were the same, the multichannel ADF behaved as a power splitter with a 50/50 division ratio and high transmittance; otherwise, it functioned as a demultiplexer to separate two different frequencies efficiently. Such a multichannel ADF not only possesses excellent filtering performance but also has strong robustness against various defects due to its topological protection property. Moreover, each output port can be switched dynamically, and each transmission channel can operate independently with little crosstalk. Our results have the potential for developing topological photonic devices in wavelength division multiplexing systems.

Efficient 1×2, 1×4, 1×8 and 1×16 photonic crystal filters/power splitters based ring resonators for modern passive optical network PON

In this paper, we propose a new architecture of [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] optical filter/power splitters operating around 1.55[Formula: see text][Formula: see text]m, based on a CPs 2D photonic crystal ring resonator for Modern Passive Optical Network (PON). This type of functionality, filtering/power splitting is introduced in this work for the first-time according literature. The designed device consists of a square array of GaAs dielectric rods immersed in air. The structure is designed and successfully simulated by the finite element method using the software COMSOL Multiphysics. From the results obtained, we note that the beam is evenly distributed for all output ports with total efficient transmissions of about 99.6%, 98.8%, 97.1% and 96.8% and low insertion losses of about 0.017, 0.052, 0.128, and −0.14[Formula: see text]dB for the [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] filter power splitter successively.

Ultra-Broadband, Compact Arbitrary Ratio Power Splitters Enabled by Adiabatic Sub-Wavelength Grating

An ultra-broadband, compact and CMOS-compatible arbitrary ratio power splitter that is based on a directional coupler is proposed on the silicon-on-insulator (SOI) platform. The proposed device consists of an adiabatic sub-wavelength grating (ASWG) and a conventional directional coupler. The wavelength dependence is greatly reduced by introducing an ASWG in the coupling region of the directional coupler. Simulation results show that our proposed device has an operating bandwidth of 250 nm for arbitrary power splitting ratios, with a transmission power variation of less than 8.5%, covering the wavelength range from 1400 nm to 1650 nm. Meanwhile, the device footprint has been narrowed to less than 46 μm. In addition, the power splitters also exhibit a low excess loss of below 0.24 dB. Our proposed ASWG-assisted power splitters show excellent potential for application in large-scale photonic integrated circuits.

Ultracompact programmable inverse-designed nanophotonic devices based on digital subwavelength structures.

Inverse design is a powerful approach to achieve ultracompact nanophotonic devices. Here, we propose an ultracompact programmable near-infrared nanophotonic device platform to dynamically implement inverse-designed near-infrared devices with different functions by programming the state of the phase-change material filled in each pixel. By tuning PCM block by block, the subwavelength condition for inverse-designed ultracompact devices is satisfied with large tuning pixel size. Based on the inverse-design device platform with a footprint of 6.4µm×8µm, we design and theoretically demonstrate four power splitters with different split ratios and one mode multiplexer working in the near-infrared band. The average excess losses for the power splitters with ratios of 0:1,1:1, 2:1, and 3:1 are less than 0.82, 0.65, 0.82, and 1.03dB over a wavelength span of 100nm, respectively. Meanwhile, the insertion losses of the mode multiplexer are 1.4 and 2.5dB for T E 0 and T E 1 mode, respectively, and the average crosstalk is less than -20 and -19d B, respectively. The five different devices could be configured online in a nonvolatile way by heating phase change materials with an off-chip laser, which may significantly enhance the flexibility of on-chip optical interconnections.

Design, development, and analysis of 1 to 4, anti-phase in-line RF power splitter for low-frequency ISM band applications

A wideband, low-loss balun-based anti-phase radio-frequency power splitter using a ferrite core is studied. The inherent impedance matching with the existing system makes it an in-line power splitter; its impedance matches at the input port without any extra impedance transformer, resulting in low insertion loss. The design approach is chosen based on the S-parameter analysis to grasp the possible implementations. The best possible implementation is analyzed based on the well-known theories, and the final S-matrix is derived. To estimate the high-frequency limitation due to the inter-winding capacitances, the implemented 1-to-4 anti-phase power splitter was tested using the vector network analyser (VNA) to find out the self-resonance of the winding coils. The practical measurements of the implemented power splitter show that the insertion loss is less than 2.1 dB, the port-to-port isolation is more than 14.5 dB, and the bandwidth is more than 23 MHz at 17 MHz.

93-THz ultra-broadband and ultra-low loss Y-junction photonic power splitter with phased inverse design.

Optical power splitters with ultra-broadband and ultra-low insertion loss are desired in the field of photonic integration. Combining two inverse design algorithms for staged optimization, we present the design of a Y-junction photonic power splitter with 700 nm wavelength bandwidth (from 1200 nm to 1900 nm) within a 0.2 dB insertion loss, corresponding to a 93 THz frequency bandwidth. The average insertion loss is approximately -0.057 dB in the valuable C-band. Moreover, we comprehensively compared the insertion loss performance of different types and sizes of curved waveguides, and also give the cases of 1:4 and 1:6 cascaded power splitters. These scalable Y-junction splitters provide new alternatives for high-performance photonic integration.

A 38-GHz demodulator with high image rejection in 65 nm-CMOS process

AbstractA high image rejection 38 GHz demodulator in TSMC 65-nm CMOS process is presented. To achieve better than −40 dBc image rejection ratio (IRR), a low I/Q mismatch 45° LO power splitter of sub-harmonic mixer is proposed. In this design, the 45° LO power splitter is composed of a Wilkinson divider, a series delay line with electrical length of 45° on one side of the divider, and a shunt 90° transmission line on the other side. This configuration is attractive because of its design simplicity and easy fabrication. Compared with the conventional techniques that utilize capacitors and inductors instead of the shunt 90° transmission line, the proposed LO power splitter can alleviate the issue of process variation. The demodulator demonstrates an IRR lower than −40 dBc from 37.5 to 41.5 GHz. In addition, conversion gain is 1.3 ± 0.9 dB from 33 to 41 GHz with 6 dBm LO power. The total direct current power consumption is 78 mW from 1.0 V supply voltage. At the modulation scheme of 4096-QAM, the proposed demodulator demonstrates 1.7% (−35.1 dB) error vector magnitude (EVM), which is very close to the EVM measurement floor 1.6% (−36 dB) of our millimeter-wave signal analyzer.

Design and simulation of a dynamically tunable 1× 2 power splitter using MZI configuration in the telecom regime

We propose an ultra-broadband, ultra-compact and a dynamically tunable power splitter on a silicon on Insulator (SOI) platform with a 220 nm thick silicon light-guiding layer, using two multimode interference (MMI) couplers connected with graphene-based waveguides as the phase-tuning section through a Mach-Zehnder Interferometer (MZI) configuration. First, we theoretically present and demonstrate a novel design for the MMI couplers by combining the plane wave expansion method (PWEM) and the mode expansion conjecture concept. To verify the proposed theory, a center-fed MMI coupler and a MMI coupler, respectively, as the input and output sections of our proposed device, are designed and simulated. The simulation results achieved by Lumerical FDTD show good agreement with the design theory. Then, a highly tunable graphene-embedded silicon waveguide, for the highly efficient modulation of the effective mod index (EMI), is duly designed using Lumerical Mode Solutions. As the two MZI arms, a pair of the proposed waveguides is introduced into the middle of the cascaded MMI couplers. Accordingly, the integration properties of the analytically designed MMI couplers and the numerically designed waveguide is demonstrated through our proposed device for the aim of achieving any wanted power splitting ratio. To this end, we consider the case that the real part of the EMI of the waveguide in the lower MZI arm is modulated by varying the graphene Fermi level values, being the same for all the layers belonging to the same waveguide, while that of the upper arm is constant. The corresponding power splitting ratio can be dynamically tuned in the range of All reported results assume TE polarization. The designed MZI-based splitter possesses a bandwidth of over the wavelength range from to for various power splitting ratios, maintaining the averaged insertion loss and the averaged power imbalance, respectively, below as low as and The overall footprint of the proposed device is also highly small, i.e., about

Broadband Microwave Photonic Mixer with Flexibly Tunable Phase Shift and Supporting Dispersion-Induced Power-Fading-Free Fiber Transmission

A broadband microwave photonic mixer with tunable phase shift and supporting dispersion-induced power-fading-free fiber transmission is proposed and demonstrated based on a dual-polarization dual-parallel Mach–Zehnder modulator (DP-DPMZM). In this scheme, the intermediate-frequency (IF)/radiofrequency (RF) signal and the local oscillation (LO) signal are applied to the four sub-MZMs biased at their minimum transmission points via a power splitter and a 90° hybrid coupler, respectively. Through mutual beating between the IF/RF and the LO modulation sidebands in a high-speed photodetector at the remote site, high-efficiency frequency conversion is achieved. The dispersion-induced power fading over long-distance fiber transmission is eliminated through setting the biased-induced phase difference between the parent-MZMs in the two sub-DPMZMs of the DP-DPMZM to be π/2. In addition, the phase shift of the frequency-converted signal can be continuously tuned over 360° through synchronously adjusting the bias voltages of the parent-MZMs in the two sub-DPMZMs. The proposed scheme is experimentally demonstrated, where a microwave photonic mixer with a 6-dB operation bandwidth of 40 GHz and supporting dispersion-induced power-fading-free transmission over 20 km SMF is realized. Meanwhile, a continuously tunable phase shift over 360° in the frequency range of 0.1 GHz to 29.9 GHz is achieved, where the power variation during phase tuning is smaller than 4 dB.

Particle Swarm Optimized Compact, Low Loss 3-dB Power Splitter Enabled by Silicon Columns in Silicon-on-Insulator

We demonstrate a 3-dB power splitter optimized by an enhanced particle swarm optimization algorithm based on a curved directional coupler, with a set of silicon columns introduced into the coupling region. The proposed device exhibits compact size, low loss and low wavelength dependence in the O-band. We employ the particle swarm optimization algorithm to engineer the dispersion by designing the radius of the silicon columns automatically. The demonstrated 3-dB power splitter enabled by silicon columns in silicon-on-insulator can achieve multiple performance metrics simultaneously according to our simulation results, with a compact footprint as small as 11.9 µm, low excess loss as low as 0.04 dB and broad 3-dB operational bandwidth of 60 nm with transmission fluctuations within 0.05 in the wavelength range from 1270 to 1330 nm. This work pioneers the silicon columns in the coupling region and adopts an enhanced particle swarm optimization algorithm to optimize device properties, providing significant potential for application in large-scale PICs as well as offering a new degree of freedom in the design of power splitters.

Efficiency enhancement of long-reach passive optical network using the polarization coding

Abstract This paper, propose a new passive optical network (PON) system structure based on the two orthogonal polarization states of the same wavelength. This method is usually applied to increase the number of simultaneous users in the network, it can double the number of potential users. The proposed technique utilized to increase split ratio and consequently increase the reach and the split ratio. This can be achieved by implementing technologies such as power splitter. In terms of bit rate, the proposed PON offers a bit rate of 10 Gbps for downstream transmissions. The results obtained in this work are shown that the proposed system can accommodate more users simultaneously for the typical Q factor is greater than 6.

Compact magnetoelectric power splitter with high isolation using ferrite/piezoelectric transformer composite

A compact, passive magnetoelectric (ME) power splitter, with a ferrite/piezoelectric transformer bilayer composite with a coil wound around it, as well as a structure-constructing strategy, was presented and developed in this research. The impedance differences in a Rosen-type PT induced by integrated transverse/longitudinal polarizations facilitated the device realization with higher isolation rather than elementary LCR lumped elements. Furthermore, the measurements of the material properties and electrical resonance behaviors for the presented ME splitter were implemented, and the power-dividing capabilities were verified by measuring the output and corresponding power for each port of the device. The experimental results demonstrated that the power for Port I in the ME power splitter reached its maximum values of 154.26 nW at R = 6 kΩ and 475.95 nW at R = 5.5 kΩ. Correspondingly, the power for Port II reached its maximum values of 12.73 nW at R = 30 kΩ and 27.85 nW at R = 12 kΩ. Consequently, a power division ratio of 3:1 was obtained under optimum load resistance and EMR conditions with constant input power. These results provided an innovative approach to constructing novel functional power electronics with solid-state materials while suggesting the promising applications for some special scenarios such as powering and controlling multi-channel LCD strings.