Photonic Crystal Power Splitter Research Articles

Topology optimization of a superconducting photonic crystal power beam splitter

The design of photonic crystals using novel materials holds significant importance in constructing high-performance, next-generation photonic crystal devices. In this study, aiming at the requirements for enhanced transmission and selectivity, we utilized a topology optimization method based on the method of moving asymptotes (MMA) to realize a high-temperature superconducting photonic crystal power splitter with low transmission loss and selectivity effects, which allows for flexible control and manipulation of optical signals. The method addresses the shortcomings of traditional scanning techniques, such as low efficiency and high resource consumption, by allowing for multi-parameter optimization. This improvement enhances the precision and effectiveness of the numerical computational iterative process. The research offers insights into the design of novel optical devices.

1 × 5 broadband photonic crystal power splitter designed by the Powell algorithm.

We propose a novel, to the best of our knowledge, 1×5 broadband power splitter based on the photonic crystal. The Powell algorithm is used to reverse-design the proposed broadband power splitter. The results show that the transmittance of each output port of the broadband photonic crystal power splitter can be adjusted by changing the radii and offsets of the dielectric rods at the junction area of each waveguide. According to the target splitting ratio, the reverse design of the structural parameters using the Powell algorithm significantly improves the optimization efficiency and splitting performance of the broadband power splitter. The designed power splitters have a wide working bandwidth of 1525-1565 nm, a flexible and designable power splitting ratio, excellent splitting performance, and a compact size, which have great application prospects in all-optical communication networks, high-density photon integration, and other fields.

A Novel Differential Optical MEMS Accelerometer Based on Intensity Modulation, Using an Optical Power Splitter

In this paper, a novel highly sensitive differential optical MEMS accelerometer based on intensity modulation is proposed by using dual optical outputs and a two-dimensional (2D) photonic crystal power splitter. A TM-polarized light source, an optical power splitter (OPS) based on 2D photonic crystal (PhC), two typical photodiodes (PDs) and three optical ports build up the optical sensing system of the proposed sensor. The functional characteristics of the proposed device based on simulation results are as follows: Mechanical sensitivity of 0.0750 nm/g, linear measurement range of ±200 g, first mechanical resonance frequency of 17.7 kHz, optical sensitivity of 4.38 %/nm with bandwidth at half maximum (FWHM) of 1 nm (0.13 THz) at optical central wavelength of 1.495 μm (200.7 T Hz). This results in an optical quality factor of 1495 and total sensitivity of 0.3285 %/g. Due to the mentioned functional characteristics, the proposed sensor can be appealing for a wide range of applications, from inertial navigation and automotive to consumer electronics.

Beam splitting characteristics of two-dimensional photonic crystals based on surface modulation

The light beam propagating characteristics of an open-type photonic crystal power splitter are investigated through modulating the structure’s surfaces. The light transmittance can be improved by optimizing the radii of air holes on the input surface. The propagating directions of the outgoing branch beams can be adjusted continuously by altering the period’s length of air holes on the output surface, and influence of the alteration of those air holes’ locations to the splitting phenomena is also studied. Furthermore, keeping the air holes’ arrangement on the output surface unchanged, the splitting behavior can also be adjusted by changing the arrangement of the air holes adjacent to the last row near the output surface. Comparing the light beam propagating behaviors along two opposite directions at normal incidence, it is shown that both the light transmittance and the light splitting characteristics can be significantly different.

Analysis of the Photonic Crystal Power Splitter Based on the Junction Defect Radius for Optimum Resonance

Nano-photonics is an emerging area of optical materials, which would take the optointegrated circuits towards progress. Photonic crystal (PC) based power splitters are useful constituents for the design of photonic integrated circuits (PICs). They are very important devices for connecting different building blocks on an integrated optical chip. In this paper, a two-dimensional PC Y-junction power splitter (21×15 μm) based on the resonance effect with circular air holes etched on a hexagonal lattice with a period a is proposed. The plane wave expansion (PWE) and finite difference time domain (FDTD) techniques are used for analyzing the structure. The simulation results show that the optimum resonance occurs when the radius of the defect hole is 0.3a, leading to the maximum and equal power distribution.

Design of a novel nano plasmonic-dielectric photonic crystal power splitter suitable for photonic integrated circuits

A novel designation of an all optical plasmonic-dielectric power splitter-filter based on 2-D square lattice photonic crystals (PhCs) is proposed. The structure is consisted of air, aluminum, silver and copper rods in silicon background. Photonic band gap (PBG) analysis and field distributions are obtained by plane wave expansion (PWE) and finite difference time domain (FDTD) methods, respectively. As electromagnetic (EM) wave is propagated, power levels lower than “0.4’’ are considered as “0’’ and higher than “0.5’’ as “1’’. For definite wavelengths, only one output port transfers the power. Therefore, the system acts as a power splitter and filter, simultaneously.The proposed structure can confine lightwave to sub-wavelength dimensions (of the order of nano meter) because the multiple plasmonic/dielectric combinations are utilized in this structure. As a result, this device can be operational in integrated optical circuits.

Design of a High-Bandwidth Y-Shaped Photonic Crystal Power Splitter for TE Modes

Design of a High-Bandwidth Y-Shaped Photonic Crystal Power Splitter for TE Modes

Photonic crystal frequency band selecting and power splitting devices based on the energy coupling effect between waveguides

The photonic crystal power splitter based on the energy coupling effect between waveguides has the advantages of compact structure, wide bandwidth, low bending loss, large angle of separation, and no external electromagnetic interference. In this paper, the power splitting characteristics of two-dimensional triangular-lattice photonic crystal coupled waveguide are theoretically studied by using the finite-difference time-domain method, and a functional device is designed in order to achieve different output power ratios within different frequency ranges.In the two-dimensional photonic crystal structure with triangular lattice, we set two adjacent straight waveguides and the light beam is introduced from one of them. Because of the energy coupling effect between the two line defects, the light energy propagates alternately in them. Based on this principle, structures of different coupling lengths are simulated and the interference effect of each surface is considered. The device with the best coupling length is achieved for three different output energy propagating characteristics at different frequencies, which include three-division, two-division and single output cases. That is to say, the incident light beam within a frequency band travels through a particular waveguide; light in another frequency band only flows through the other two output waveguides; light in the third frequency band is assigned to all the three output waveguides equally. However, the frequency band width for the high-quality light beam splitting area as well as the transmittance contrast of the other two functional band areas are not very ideal.Based on the above numerical results, two transmission modes in the coupling waveguides are achieved by changing the cross section shape of the dielectric column in the coupling region and also by changing the connecting position between the output branch waveguide and the energy-coupling waveguide. Through the above change, the splitting performance is further optimized.By detecting and analyzing the relative intensity of the three output waveguides, we can determine the range of the incident light beam. Furthermore, the frequency ranges of the three different light output characteristics can be adjusted flexibly by changing the cross section shape of the dielectric column in the coupling region or by changing the connecting position of output waveguides. The functional device proposed in this paper has a high transmittance contrast ratio and a compact structure, which will promote the practical application of the all-optical functional devices in the fields of large-scale all-optical complex integration.

Transmission performance of 1 × 2 type photonic crystal power splitter with ring resonators

The structure of 1×2 type photonic crystal power splitter with ring resonators is designed in a two-dimension square-lattice dielectric-rod photonic crystal structure, and it consists of one input and two outputs. Its transmission performance is investigated by using the finite-difference time-domain (FDTD) method. The results show that the structure has high transmission efficiency in the third communication window (wavelength 1550nm), can split pass band electromagnetic waves equally. It is compact with low loss and design flexibility in propagation direction of electromagnetic waves.

Numerical investigation on cascaded 1 × 3 photonic crystal power splitter based on asymmetric and symmetric 1 × 2 photonic crystal splitters designed with flexible structural defects.

We propose a photonic crystal slab-based 1 × 3 power splitter with high output transmission and equal power distribution. It is designed by cascading an asymmetric 1 × 2 power splitter and a symmetric 1 × 2 power splitter. Desired equal power splitting is achieved by introducing and optimizing the splitting region of the 1 × 2 power splitters with flexible structural defects. Simulations were carried out by using 3-D Finite Difference Time Domain method showing equal normalized power distributions of 29.6%, 28.9% and 30.5% at 1550 nm optical wavelength. In addition, equal power splitting also takes place at 1561 nm.

Study the Coupled-Cavity Waveguides Photonic Crystal Power Splitter

We propose a photonic crystal power splitter that allows the electromagnetic waves with a phase shift of 1800between output signals. The splitter consists of two parallel coupled-cavity waveguides placed in proximity. On the basis of the guided mode propagation analysis method, the self-imaging effect is discussed for the case of symmetric incidence. The finite-difference time-domain method is used to simulate the propagation of the beam and experimentally demonstrated. The results show that both output paths have the same physical length, the two output signals are synchronized. The splitter is very attractive for splitting high-speed optical signals in integrated optical circuits.

1×4 Power Splitter Based on Cascaded Multimode Interference Photonic Crystal Waveguide

Using of cascaded multimode interference waveguides in 2D photonic crystal power splitter are investigated by modeling and computation. Results show that with a five line defect waveguides and one pair of three line defect waveguides integrated, the total normalized transmission can be high as 94.9% with 30nm broad spectrum calculated and simulated by finite-difference time-domain method.

A 1x4 power-splitter based on photonic crystal Y-splitter and directional couplers

A 1×4 photonic crystal power splitter operating in the optical communication window is demonstrated by plane-wave expansion and finite-difference time-domain simulations. The device consists of one Y-junction and two directional couplers. Double 60o bends are formed at the exit of directional couplers to prevent crosstalk. The Y-junction, double bends and coupling holes at the directional couplers are optimized to increase the transmission efficiency at the output ports. The simulation results exhibit almost equal power splitting with low loss characteristic. The investigated design shows potential for optical switching and routing applications in optical communications.

Slow light transmission in a photonic crystal power splitter with parallel outputs

In this paper, we investigate coupling of light to slow modes in a photonic crystal power splitter composed of a Y-junction and two 60° bends. First, a combination of two cascaded bends which is commonly used in integrated photonic crystal circuits is studied in slow light frequency regime. We propose a structure that its transmission spectrum covers the high group-index frequencies near the band edge. Also, by structural modifications, high transmission near to 95% is achieved in slow light bandwidth. Next, we study the complete structure of a photonic crystal power splitter with parallel outputs based on a Y-junction integrated with two 60° bends. Using modified bends and reducing sharpness of Y-junction, the efficiency of splitting increases in both high and low group-index frequency bands. The optimized structure has an average efficiency of 82% in slow mode regime. This structure can be used in photonic crystal based slow light devices, such as Mach-Zehnder interferometers.

Analysis of Two-Dimensional Photonic Crystal Optical Power Splitter with Microcavity

Analysis of Two-Dimensional Photonic Crystal Optical Power Splitter with Microcavity

Design, Simulation & Optimization of 2D Photonic Crystal Power Splitter

A very compact (80 - 100 μm2) integrated power splitting devices with two outputs (1 × 2), four outputs (1 × 4) and six outputs (1 × 6) channel has been designed, simulated and optimized for Telecommunication purpose with T-Junction, Y-Junction, PC line defect waveguides integrated with multimode interference block (PCLD-MMI) and multiple line defect PC waveguides (MLDPCW) configurations. The optical modeling of these proposed structures was investigated by finite difference time domain (FDTD) simulation. With the optimization of the parameters (Hole Radius, R = 0.128 μm, Input Diameter, D = 1.02 μm, Input wavelength, λ = 1.55 μm, Substrate Reflective Index, nsub = Si(1.52), Photonic Crystal Material, npcs = InAs(3.45), and Rectangular crystal structure), 1 × 2 for Y-Junction (100%), 1 × 4 for T-Junction (92.8%) and 1 × 6 configuration for MLDPCW (81%) show maximum power transmission.

带有环形谐振器的1×2光子晶体功率分配器传输性能

带有环形谐振器的1×2光子晶体功率分配器传输性能

Design of novel power splitters by directional coupling between photonic crystal waveguides

The design of a novel photonic crystal waveguide power splitter is presented. The proposed power splitter has three output ports, the coupling among three parallel photonic crystal waveguides can be considered as a multimode interference (MMI), and the positions of output waveguides are determined by those of twofold images which are formed by the self-imaging effect of multimode interference. The transmission characteristics of the splitter are investigated by using the finite-difference time domain (FDTD) and the plane wave expansion method. The output optical power in each port can be controlled by adjusting the radius of the dielectric rods in the coupling region, and the coupling effect among output ports is decreased by using the T-shaped output port. The results indicate that 1× 1, 1×2 and 1×3 type power splitters can be realized when the normalized radius of dielectric rods in the coupling region is 0.130, 0.180, 0.152 or 0.221, respectively.

Power splitters with different output power levels based on directional coupling

The properties of a wideband photonic crystal power splitter with different output power levels based on directional coupling are investigated numerically with the finite-difference time-domain method. The effects of changing the coupling length and radius of the coupling rods between parallel waveguides on output transmissions are investigated. By further splitting power in each branch a power splitter with four output branches is proposed.

Design of efficient photonic crystal bend and power splitter using super defects

We propose a new scheme for an efficient photonic crystal 90° bend and power splitter. First we design a 90° bend by placing a super defect at the junction of two orthogonal photonic crystal waveguides. We changed the parameters of the super defect to optimize the transmission coefficient of the bent structure. Our two-dimensional (2D) simulations show more than 85% efficiency over a wide range of wavelengths. Then using this new scheme and adding another waveguide we design a new power splitter and optimize it with the same procedure. We used the coupled mode theory to analytically investigate the structures and finite difference time domain to simulate and optimize the structures performances.