Characterization and modeling of Fano resonances in chalcogenide photonic crystal membranes (original) (raw)
Fano-Resonance Photonic Crystal Membrane Reflectors at Mid- and Far-Infrared
Ieee Photonics Journal, 2013
We report here single-layer ultracompact Fano-resonance photonic crystal membrane reflectors (MRs) at mid-infrared (IR) and far-IR (FIR) bands, based on single layer crystalline Si membranes. High-performance reflectors were designed for surfacenormal incidence illumination with center operation wavelengths up to the 75-m FIR spectral band. Large-area patterned MRs were also fabricated and transferred onto glass substrates based on membrane transfer processes. Close to 100% reflection was obtained at the $76-m spectral band, with a single-layer Si membrane thickness of 18 m. Such Fanoresonance-based membranes reflectors offer great opportunities for high-performance ultracompact dielectric reflectors at IR and THz regions.
Photonic Eigenmodes in a Photonic Crystal Membrane
ISRN Optics, 2012
Photonic membranes are the most widely used kind of 2D photonic crystals in signal processing. Nevertheless, some important aspects of electromagnetic field behavior in membrane like photonic crystals (MPCs) need detail investigation. We develop the approach close to resonant coupling modes method which unites both external and intrinsic problems, in-plane and out-of-plane geometries, and resonator properties of MPC. The resonator standing modes are excited by an external source through the special inputs and may be controlled due to the nonlinear coating. Typical photonic manifestations are studied for Si/SiO22D membrane resonators of rectangular.
Modal approach for tailoring the absorption in a photonic crystal membrane
In this paper, we propose a method for tailoring the absorption in a photonic crystal membrane. For that purpose, we first applied time domain coupled mode theory to such a subwavelength membrane and demonstrated that 100% resonant absorption can be reached even for a symmetric membrane, if degenerate modes are involved. Design rules were then derived from this model in order to tune the absorption. Subsequently, finite difference time domain simulations were used as a proof of concept and carried out on a low absorbing material (extinction coefficient = 10−2) with a high refractive index corresponding to the optical indices of amorphous silicon at around 720 nm. In doing so, 85% resonant absorption was obtained, which is significantly higher than the commonly reported 50% maximum value. Those results were finally analyzed and confronted to theory so as to extend our method to other materials, configurations and applications.
Optics Express, 2013
We study the reflectivity spectra of photonic crystal slab cavities using an extension of the scattering matrix method that allows treating finite sizes of the spot of the excitation beam. The details of the implementation of the method are presented and then we show that Fano resonances arise as a consequence of the electromagnetic interference between the discrete contribution of the fundamental cavity mode and the continuum contribution of the light scattered by the photonic crystal pattern. We control the asymmetry lineshape of the Fano resonance through the polarization of the incident field, which determines the relative phase between the two electromagnetic contributions to the interference. We analyse the electric field profile inside and outside of the crystal to help in the understanding of the dependence on polarization of the reflectivity lineshape. We also study with our implementation the dependence of the Fano resonances on the size of the incident radiation spot.
Chalcogenide glass photonic crystals
2008
All-optical switching devices are based on a material possessing a nonlinear optical response, enabling light to control light, and are enjoying renewed interest. Photonic crystals are a promising platform for realizing compact all-optical switches operating at very low power and integrated on an optical integrated circuit. In this review, we show that by making photonic crystals from a highly nonlinear chalcogenide glass, we have the potential to integrate a variety of active devices into a photonic chip. We describe the fabrication and testing of two-dimensional Ge 33 As 12 Se 55 chalcogenide glass photonic crystal membrane devices (waveguides and microcavities). We then demonstrate the ability to post-tune the devices using the material photosensitivity. In one proposal we hope to introduce a double-heterostructure microcavity using the photosensitivity alone. #
Fabrication of planar photonic crystals in a chalcogenide glass using a focused ion beam
Optics Express, 2005
Free-standing "AMTIR-1" (Ge 33 As 12 Se 55) chalcogenide glass films have been patterned using a focused ion beam (FIB) to create twodimensional photonic crystal membranes. The triangular lattices were selected for a photonic bandgap relevant to fiber telecommunications. Optical measurements of transmission spectra as a function of incident angle showed clear signs of Fano resonances, indicating that the structures had strongly modified guided modes.
Fano resonances of photonic crystal slabs
A Bloch mode theory for diffraction of plane waves by planar PC slabs is developed. The theory provides physical insight into the origin of Fano resonances, allowing a simple pole model to be deduced rigorously.
Resonant Photonic States in Coupled Heterostructure Photonic Crystal Waveguides
Nanoscale Research Letters, 2010
In this paper, we study the photonic resonance states and transmission spectra of coupled waveguides made from heterostructure photonic crystals. We consider photonic crystal waveguides made from three photonic crystals A, B and C, where the waveguide heterostructure is denoted as B/A/C/A/B. Due to the band structure engineering, light is confined within crystal A, which thus act as waveguides. Here, photonic crystal C is taken as a nonlinear photonic crystal, which has a band gap that may be modified by applying a pump laser. We have found that the number of bound states within the waveguides depends on the width and well depth of photonic crystal A. It has also been found that when both waveguides are far away from each other, the energies of bound photons in each of the waveguides are degenerate. However, when they are brought close to each other, the degeneracy of the bound states is removed due to the coupling between them, which causes these states to split into pairs. We have also investigated the effect of the pump field on photonic crystal C. We have shown that by applying a pump field, the system may be switched between a double waveguide to a single waveguide, which effectively turns on or off the coupling between degenerate states. This reveals interesting results that can be applied to develop new types of nanophotonic devices such as nano-switches and nanotransistors. Keywords Photonic crystal heterostructures Á Nonlinear photonic crystals Á Photonic crystal waveguides Á Nanophotonics Á Resonant tunneling Á Coupled waveguides
Sharp bends in photonic crystal waveguides as nonlinear Fano resonators
Optics Express, 2005
We demonstrate that high transmission through sharp bends in photonic crystal waveguides can be described by a simple model of the Fano resonance where the waveguide bend plays a role of a specific localized defect. We derive effective discrete equations for two types of the waveguide bends in two-dimensional photonic crystals and obtain exact analytical solutions for the resonant transmission and reflection. This approach allows us to get a deeper insight into the physics of resonant transmission, and it is also useful for the study and design of power-dependent transmission through the waveguide bends with embedded nonlinear defects.
Frequency control of photonic crystal membrane resonators by monolayer deposition
We study the response of GaAsphotonic crystal membrane resonators to thin-film deposition. Slow spectral shifts of the cavity mode of several nanometers are observed at low temperatures, caused by cryo-gettering of background molecules. Heating the membrane resets the drift and shielding will prevent drift altogether. In order to explore the drift as a tool to detect surface layers, or to intentionally shift the cavity resonance frequency, we studied the effect of self-assembledmonolayers of polypeptide molecules attached to the membranes. The 2-nm-thick monolayers lead to a discrete step in the resonance frequency and partially passivate the surface.
Planar defects in three-dimensional chalcogenide glass photonic crystals
Optics Letters, 2011
Here we report on the direct laser writing fabrication of Fabry-Perot-type planar microcavities in a threedimensional (3D) photonic crystal (PhC) embedded within a high-refractive nonlinear chalcogenide glass (ChG) film. The fabricated planar microcavities in a nonlinear ChG 3D PhC facilitate the observation of resonant modes inside the stop gap. The experimental results show that the length of the planar cavity can be well controlled by the fabrication power and thus be used to tune the defect modes. The tunability of the observed defect modes is confirmed by the theoretical prediction.
Analysis of guided resonances in photonic crystal slabs
Physical Review B, 2002
We present a three-dimensional analysis of guided resonances in photonic crystal slab structures that leads to a new understanding of the complex spectral properties of such systems. Specifically, we calculate the dispersion diagrams, the modal patterns, and transmission and reflection spectra of these resonances. From these calculations, a key observation emerges involving the presence of two temporal pathways for transmission
Coupled-resonator-induced reflection in photonic-crystal waveguide structures
Optics Express, 2008
We study the resonant transmission of light in a coupled-resonator optical waveguide interacting with two nearly identical side cavities. We reveal and describe a novel effect of the coupled-resonator-induced reflection (CRIR) characterized by a very high and easily tunable quality factor of the reflection line, for the case of the inter-site coupling between the cavities and the waveguide. This effect differs sharply from the coupled-resonator-induced transparency (CRIT) -- an all-optical analogue of the electromagnetically-induced transparency -- which has recently been studied theoretically and observed experimentally for the structures based on micro-ring resonators and photonic crystal cavities. Both CRIR and CRIT effects have the same physical origin which can be attributed to the Fano-Feshbach resonances in the systems exhibiting more than one resonance. We discuss the applicability of the novel CRIR effect to the control of the slow-light propagation and low-threshold all-optical switching.
Design of a two-dimensional chalcogenide photonic crystal for application as a band pass filter
NATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF MATERIALS: NCPCM2020, 2021
In this paper, we have designed a two-dimensional (2D) photonic crystal structure using chalcogenide glass for band pass filter application. A two dimensional square lattice structure is taken with chalcogenide rods in air. The filter is formed by creating two linear waveguides on both side of a point defect. The resonant mode is then coupled between the waveguide and point defect, which allows the requisite frequencies to pass. The effect of size of defect on the transmission and electric field distribution is also studied.
Temporal coupled-mode theory for the Fano resonance in optical resonators
Journal of the Optical Society of America A, 2003
We present a theory of the Fano resonance for optical resonators, based on a temporal coupled-mode formalism. This theory is applicable to the general scheme of a single optical resonance coupled with multiple input and output ports. We show that the coupling constants in such a theory are strongly constrained by energyconservation and time-reversal symmetry considerations. In particular, for a two-port symmetric structure, Fano-resonant line shape can be derived by using only these symmetry considerations. We validate the analysis by comparing the theoretical predictions with three-dimensional finite-difference time-domain simulations of guided resonance in photonic crystal slabs. Such a theory may prove to be useful for response-function synthesis in filter and sensor applications.
Photowritten high-Q cavities in two-dimensional chalcogenide glass photonic crystals
Optics Letters, 2009
We demonstrate a high-Q ͑ϳ125,000͒ photonic crystal (PhC) cavity formed using a postprocessing optical exposure technique where the refractive index of a photosensitive chalcogenide PhC is modified locally. The evolution of the cavity resonances was monitored in situ during writing using a tapered fiber evanescent coupling system, and the Q of 125,000 represents 1 order of magnitude increase over previously reported cavities in two-dimensional chalcogenide glass PhC.
Photosensitive post-tuning of chalcogenide photonic crystal waveguides
2007
We present experimental results on post-tuning the dispersion of a two-dimensional photonic crystal waveguide made from Ge 33 As 12 Se 55 chalcogenide glass by exploiting the material photosensitivity to nearbandgap light. The change in the refractive index and volume of the material in response to exposure to 633nm light resulted in a shift of more than 5nm in the resonant coupling wavelength between a tapered optical fiber and the modes of a W1 waveguide. This represents a first proof of principle demonstration of the photosensitive post-tuning of a planar photonic crystal device.