Mini-stop bands in single heterojunction photonic crystal waveguides
Online Publication Date2013-03-20
Print Publication Date2013-03
Permanent link to this recordhttp://hdl.handle.net/10754/334646
MetadataShow full item record
AbstractSpectral characteristics of mini-stop bands (MSB) in line-defect photonic crystal (PhC) waveguides and in heterostructure PhC waveguides having one abrupt interface are investigated. Tunability of the MSB position by air-fill factor heterostructure PhC waveguides is utilized to demonstrate different filter functions, at optical communication wavelengths, ranging from resonance-like to wide band pass filters with high transmission. The narrowest filter realized has a resonance-like transmission peak with a full width at half maximum of 3.4 nm. These devices could be attractive for coarse wavelength selection (pass and drop) and for sensing applications. 2013 Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License.
CitationShahid N, Amin M, Naureen S, Anand S (2013) Mini-stop bands in single heterojunction photonic crystal waveguides. AIP Advances 3: 032136. doi:10.1063/1.4798304.
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as This article is distributed under a Creative Commons Attribution 3.0 Unported License.
Showing items related by title, author, creator and subject.
High-modulation-efficiency, integrated waveguide modulator-laser diode at 448 nmShen, Chao; Ng, Tien Khee; Leonard, John T.; Pourhashemi, Arash; Oubei, Hassan M.; Alias, Mohd Sharizal; Nakamura, Shuji; DenBaars, Steven P.; Speck, James S.; Alyamani, Ahmed Y.; Eldesouki, Munir M.; Ooi, Boon S. (ACS Photonics, American Chemical Society (ACS), 2016-02-05) [Article]To date, solid-state lighting (SSL), visible light communication (VLC) and optical clock generation functionalities in the blue-green color regime have been demonstrated based on discrete devices, including light-emitting diodes, laser diodes, and transverse-transmission modulators. This work presents the first integrated waveguide modulator-laser diode (IWM-LD) at 448 nm, offering the advantages of small-footprint, high-speed, and low power-consumption. A high modulation efficiency of 2.68 dB/V, deriving from a large extinction ratio of 9.4 dB and a low operating voltage range of 3.5 V, was measured. The electroabsorption characteristics revealed that the modulation effect, as observed from the red-shifting of the absorption edge, was resulted from the external-field-induced quantum-confined-Stark-effect (QCSE). A comparative analysis of the photocurrent versus wavelength spectra in semipolar- and polar-plane InGaN/GaN quantum wells (QWs) confirmed that the IWM-LD based on semipolar (20¯2 ¯1) QWs was able to operate in a manner similar to other III-V materials typically used in optical telecommunications, due to the reduced piezoelectric field. Utilizing the integrated modulator, a -3dB bandwidth of ~1 GHz was measured, and a data rate of 1 Gbit/s was demonstrated using on-off keying (OOK) modulation. Our experimental investigation highlighted the advantage of implementing the IWM-LD on the same semipolar QW epitaxy in enabling a high-efficiency platform for SSL-VLC dual-functionalities.
Theory and Design of Tunable Full-Mode and Half-Mode Ferrite Waveguide IsolatorsGhaffar, Farhan A.; Bray, Joey R.; Vaseem, Mohammed; Roy, Langis; Shamim, Atif (IEEE Transactions on Magnetics, Institute of Electrical and Electronics Engineers (IEEE), 2019-04-25) [Article]Ferrite isolators are attractive due to their excellent isolation, low loss, good linearity, and high-power performance. However, these devices usually operate over a single-frequency band. Multiband applications are possible if the isolation bandwidth of an isolator can be tuned. This paper presents a tunable waveguide-based full-mode ferrite isolator as well as a more compact half-mode tunable isolator, both fabricated on yttrium-iron-garnet substrates. For the first time, theory and design guidelines for the center frequency, bandwidth, and tuning of the ferrite isolators' unidirectional magnetostatic surface wave (MSW) mode are presented. The proposed theoretical model reveals that the isolation bandwidth can exceed 100% if the magnetization-to-bias field ratio is higher than 8. Although the full-mode design is fabricated using a conventional subtractive technique, the half-mode design is implemented using inkjet printing technology. The full-mode isolator provides a maximum bandwidth of 45% and a peak isolator figure of merit (IFM) of over 65 dB at 7 GHz, whereas the half-mode design has a maximum bandwidth of 59% and a peak IFM of 76.7 dB at 7.5 GHz. The tuning of the center frequency is from 7 to 10.7 GHz for the full-mode and from 4.4 to 9.9 GHz for the half-mode design using magnetic field strengths up to 2500 and 2400 Oe, respectively. This paper demonstrates the versatility of ferrite isolators as tunable microwave devices for reconfigurable RF applications.
Omnidirectional Photonic Band Gap Using Low Refractive Index Contrast Materials and its Application in Optical WaveguidesVidal Faez, Angelo (2012-07) [Thesis]
Advisor: Fratalocchi, Andrea
Committee member: Ooi, Boon S.Researchers have argued for many years that one of the conditions for omnidirectional reflection in a one-dimensional photonic crystal is a strong refractive index contrast between the two constituent dielectric materials. Using numerical simulations and the theory of Anderson localization of light, in this work we demonstrate that an omnidirectional band gap can indeed be created utilizing low refractive index contrast materials when they are arranged in a disordered manner. Moreover, the size of the omnidirectional band gap becomes a controllable parameter, which now depends on the number of layers and not only on the refractive index contrast of the system, as it is widely accepted. This achievement constitutes a major breakthrough in the field since it allows for the development of cheaper and more efficient technologies. Of particular interest is the case of high index contrast one-dimensional photonic crystal fibers, where the propagation losses are mainly due to increased optical scattering from sidewall roughness at the interfaces of high index contrast materials. By using low index contrast materials these losses can be reduced dramatically, while maintaining the confinement capability of the waveguide. This is just one of many applications that could be proven useful for this discovery.