Photonic Crystal Resonant Cavities Research Articles

基于三角晶格光子晶体谐振腔的双通道解波分复用器

基于三角晶格光子晶体谐振腔的双通道解波分复用器

Significant role of photonic crystal resonant cavities in WDM and DWDM communication tunable filters

A method of photonic crystal filter using resonant cavities in two dimensional structures suitable for WDM and DWDM communication applications is proposed. For the design of the structure, movement of defects as resonant cavities is utilized. Tuning the desired wavelengths with characteristics according to ITU-T standard is shown. By changing characteristics such as radius of defects, distance of them from each other and location of defects, a compact optical filter proper for optical integrated circuits is proposed. Also, the combined effect of introduction of variable radius of defects and distances of them from each other, resulted interesting characteristics.

一种光子晶体谐振腔的TM模特性

A model of two-dimensional photonic band gap structures resonant cavity is proposed made by GaAs pillars in air with graphite lattice.Its TMy mode formant wavelength changing with stress and temperature is calculated by finite difference time domain method.The results show that no mater what direction for the stress acting on the resonant cavity,there will be a good linear characteristic between the formant wavelength and the stress,the sensitivity responding to stress is 0.013 69 nm/Mpa.Meanwhile,it is found that the sensitivities responding to stress along x and y direction are the same.There is a sectional linear characteristic between the main formant wavelength and temperature for this kind of photonic crystal resonant cavity,and the biggest sensitivity responding to temperature is 1.4 nm/℃.Furthermore,the results show that there is a make-and break key characteristic for the proposed resonant cavity.

Investigation on two dimensional photonic crystal resonant cavity based bandpass filter

In this paper, different cavities, namely quasi square, tri-quarter square, square, hexagonal, circular, elliptical, diamond and annular ring based photonic crystal bandpass filters (PCBPFs) are proposed and investigated by exploiting coupling between two in-line quasi waveguides and a resonant cavity. The resonant wavelength, output efficiency and bandwidth of designed PCBPFs are studied by varying the size of the cavity. The normalized transmission spectra of PCBPF are observed using 2D finite difference time domain (FDTD) method. The photonic band gap (PBG) is calculated by plane wave expansion (PWE) method. The circular cavity based PCBPF gives better performance than others because of its circular resonating modes. The number of passbands is increased linearly while increasing the size of the cavity. The overall size of the PCBPF chip is about 11.4μm×11.4μm, which is more suitable for photonic integrated circuits (PIC), wavelength division multiplexing (WDM) systems and sensing applications.

Temperature characteristic of photonic crystals resonant cavitycomposed of GaAs pillars with graphite lattice

A model of two-dimensional photonic band gap structure resonant cavity composed of GaAs pillars with graphite lattice is proposed. The variation of its TEy mode formant wavelength with temperature is calculated by finite difference time domain method. The results show that there is a sectional linear characteristic between the main formant wavelength and temperature for this kind of photonic crystal resonant cavity, and the sensitivity responding to temperature is more than 1.60nm/℃. At the same time, the results show that this kind of resonant cavity possesses an excellent characterisitc of frequency switching. Finally, the cause for its switching characteristic is explained by the calculated results.

Design of plasmonic photonic crystal resonant cavities for polarization sensitive infrared photodetectors

We design a polarization-sensitive resonator for use in mid-infrared photodetectors, utilizing a photonic crystal cavity and a single or double-metal plasmonic waveguide to achieve enhanced detector efficiency due to superior optical confinement within the active region. As the cavity is highly frequency and polarization-sensitive, this resonator structure could be used in chip-based infrared spectrometers and cameras that can distinguish among different materials and temperatures to a high degree of precision.

2D Analysis of multimode photonic crystal resonant cavities with the finite volume time domain method

In this paper an accurate analysis of two-dimensional (2D) Photonic Crystal (PhC) based multimode resonant cavities is carried out. The analysis is performed with a robust and accurate Finite Volume Time Domain (FVTD) technique. The analysis proves the ability of the FVTD method to extract different resonant modes from a multimode PhC resonant cavity with the use of appropriate source profiles. A detailed explanation on how the source is engineered and used to excite different modes is given. Furthermore, parameters such as resonant frequency and quality factor for each resonant mode are accurately calculated.

Spectral properties of photonic crystal double heterostructure resonant cavities

Spectral properties of photonic crystal double heterostructure resonant cavities are calculated numerically using the three-dimensional finite-difference time-domain method. Resonance frequencies and quality factors are reported for various bound states that form near stationary points in the photonic crystal dispersion diagram. The associated electric field spatial profiles are presented indicating potential for in-plane laser optimization. In addition, Fabry-Perot oscillations are observed in the spectra.

Characteristic analysis of photonic crystal resonant cavity in the terahertz region

In this letter, a kind of two-dimensional photonic crystal structure applicable to THz devices is designed, and how to form a microcavity in this structure is discussed. The primary properties of the resonant cavity are analyzed, in which plane wave expansion method is used to make the calculation and the simulation. We’ve studied the variation of the bandgap structure and resonant frequency in THz region by changing the parameters, such as lattice constant, dielectric constant contrast and filling factor. The research results provided theoretical support for manufacturing the THz devices and the application of THz system.

Design of Photonic Crystal Resonant Cavity Using Overmoded Dielectric Photonic Band Gap Structures

An overmoded photonic crystal resonant cavity with two dimensional dielectric lattice structures is proposed and simulated. The dominant mode is a higher-order TM03-like at the frequency of 31.14GHz, the fundamental mode and most other modes are not supported by the cavity. The structure would be potential for application in accelerator, gyrotron and klystron in Ka-band. DOI: 10.2529/PIERS061007043414

Modeling of two-dimensional photonic crystal resonant cavities incorporating elliptically shaped dielectric cylinders

Modeling of photonic crystal structures is an ongoing challenge. This letter is devoted to the theoretical modeling of photonic crystal resonant cavities, composed of elliptically shaped dielectric pillars. Through this rigorous study, we can examine the impact of the elliptical-shape deformations to important quantities related to the photonic crystal cavity performance, such as the quality factor and the resonance frequency.

Measurement of the phase shift upon reflection from photonic crystals

The phase dependence of light reflected from colloidal photonic crystals is measured using a large resonant cavity and self-assembled colloidal photonic crystals. We measure the expected phase shift upon reflection from the photonic crystal, which varies from 0to180deg across the photonic crystal stop band. These measurements are then fed directly into the design of photonic crystal cavities. We obtain a measure for the precision needed in the fabrication of photonic crystal resonant cavities.

Nonlinear response of silicon photonic crystal micresonators excited via an integrated waveguide and fiber taper

A technique is demonstrated which efficiently transfers light between a tapered standard single-mode optical fiber and a high-Q, ultra-small mode volume, silicon photonic crystal resonant cavity. Cavity mode quality factors of 4.7x10(4) are measured, and a total fiber-to-cavity coupling efficiency of 44% is demonstrated. Using this efficient cavity input and output channel, the steady-state nonlinear absorption and dispersion of the photonic crystal cavity is studied. Optical bistability is observed for fiber input powers as low as 250 microW, corresponding to a dropped power of 100 microW and 3 fJ of stored cavity energy. A high-density effective free-carrier lifetime for these silicon photonic crystal resonators of ~ 0.5 ns is also estimated from power dependent loss and dispersion measurements.

Finite-Element Time-Domain Analysis of 2-D Photonic Crystal Resonant Cavities

An efficient novel time-domain finite-element approach for the analysis of photonic crystal resonant cavities is here introduced. This approach includes a current source, the full-band scheme, isoparametric triangular elements, and perfectly matched layers. The resonant frequency, quality factor, effective modal area, and field distribution can be obtained in a single simulation.

Design of photonic crystal waveguides for evanescent coupling to optical fiber tapers and integration with high-Q cavities

We describe a novel scheme based on evanescent guided-wave coupling for optically interfacing between conventional fiber-optic and planar photonic crystal devices such as waveguides and resonant cavities. By considering the band structure of bulk photonic crystal slabs, we analyze the k space properties of a linear defect waveguide and establish a set of design rules to ensure efficient evanescent coupling with optical fiber tapers. These rules are used to design a waveguide in a square-lattice photonic crystal. The coupling efficiency is calculated with a coupled-mode theory incorporating the finite-difference time-domain-calculated uncoupled modes of the fiber taper and photonic crystal waveguide. On the basis of this coupled-mode theory, 95% power transfer from the fiber taper to the photonic crystal waveguide is possible over a coupling length of 80 lattice periods and with a bandwidth of 1.5% of the center wavelength. The integration of this waveguide with a photonic crystal defect resonant cavity is also presented, thus showing the usefulness of the combined fiber taper and photonic crystal waveguide system for efficient, optical fiber-based probing of optical elements based on planar photonic crystal technologies.

Quality factors in single-defect photonic-crystal lasers with asymmetric cladding layers

We present quality factors of single-defect photonic-crystal resonant cavities with asymmetric cladding layers. The resonators studied here are dielectric slabs patterned with two-dimensional photonic crystals on a sapphire substrate. Three-dimensional finite-element and finite-difference time-domain routines were used to analyze the electromagnetic properties of these cavities. We observe that high quality factors (∼800) can be obtained in these cavities for reasonable structures with thick enough dielectric slabs. This work was motivated by the need to place photonic-crystal resonators on a substrate to improve heat dissipation in photonic-crystal lasers.