Results 71 to 80 of about 247,892 (261)

Polarization-Insensitive Concentric Circular Grating Filters Featuring a Couple of Resonant Peaks

IEEE Photonics Journal, 2015
We demonstrate here guided mode resonance (GMR) concentric circular grating filters (CCGFs) on an HfO2-on-silicon platform. The fabricated devices are realized with a membrane structure by completely removing the silicon substrate beneath the HfO2 device
Wei Wang, Qifa Liu, Gangyi Zhu, Xin Li, Shumin He, Tongliang Sa, Gao, Yongjin Wang   +7 more
doaj   +1 more source

Shallow grates

Theoretical Computer Science, 1994
This note gives a construction for a family of weak grates; that is, acyclic digraphs of logarithmic depth with this property: A superlinear number of pairs of vertices remain connected after removing any sufficiently small linear sized vertex set. The construction is based on one by Schnitger for acyclic digraphs with a similar property.
openaire   +1 more source

Diffraction at a Curved Grating: Approximation by an Infinite Plane Grating

Journal of Mathematical Analysis and Applications, 1996
The effect of curvature of a cylindrical grating on the diffraction of TE and TM polarized electromagnetic plane waves is considered. For every ratio of the wavelength \(\lambda\) to the period \(d\) a local approximation is established in the planar field by a plane infinite grating, when the radius \(R\) of the circular grating goes to infinity ...
Abboud, Toufic, Ammari, Habib
openaire   +2 more sources

Development of high-speed directly-modulated DFB and DBR lasers with surface gratings [PDF]

, 2011
The conventional distributed feedback and distributed Bragg reflector edge-emitting lasers employ buried gratings, which require two or more epitaxial growth steps.
M. Dumitrescu, Sek, G., REITHMAIER J. P., EISENSTEIN G., KARINEN J., P. Bardella, P. Melanen, MELANEN P., GREADY D., SEK G., G. Sek, O. Parillaud, S. Afzal, Laakso, A., J. Telkkälä, Reithmaier J.-P., Afzal, S., P. Uusimaa, Montrosset, Ivo, D. Gready, PARILLAUD O., Melanen, P., Bardella, Paolo, Vallone, Marco Ernesto, VIHERIÄLÄ J., KAMP M., Telkkälä, J., J.-P. Reithmaier, J. Karinen, Parillaud, O., Dumitrescu, M., DUMITRESCU M., Gready, D., M. Vallone, M. Krakowski, G. Eisenstein, Uusimaa, P., Viheriälä, J., A. Laakso, I. Montrosset, Eisenstein, G., J. Viheriälä, Karinen, J., AFZAL S., LAAKSO A., TELKKÄLÄ J., UUSIMAA P., Kamp, M., M. Kamp   +48 more
core   +1 more source

Narrow Linewidth Distributed Bragg Reflectors Based on InGaN/GaN Laser

Micromachines, 2019
A variety of emerging technologies, such as visible light communication systems, require narrow linewidths and easy-to-integrate light sources. Such a requirement could be potentially fulfilled with the distributed Bragg reflector (DBR) lasers, which are
Wuze Xie, Junze Li, Mingle Liao, Zejia Deng, Wenjie Wang, Song Sun   +5 more
doaj   +1 more source

Review of long period fiber gratings written by CO₂ laser

, 2010
This paper presents a systematic review of long period fiber gratings (LPFGs) written by the CO2 laser irradiation technique. First, various fabrication techniques based on CO2 laser irradiations are demonstrated to write LPFGs in different types of ...
Yiping Wang, Wang, Yiping
core   +1 more source

Integrated chirped Bragg gratings with control over complex reflectivity [PDF]

, 2009
In this paper, a fully post-growth device grating geometry based on etched sidewall gratings is presented. The grating is written on a ridge waveguide with the grating recess depth, d, and the waveguide width, W, being design parameters.
Marc Sorel, Sorel, M., Michael J. Strain, Strain, M.J.   +3 more
core   +1 more source

Reflective Optical Encoder Capitalizing on an Index Grating Imbedded in a Compact Smart Frame

IEEE Photonics Journal, 2014
A reflective optical encoder has been proposed and realized capitalizing on a miniaturized sensing head, which integrates both a pair of index gratings and a beam router in a plastic smart frame. The index gratings play a role in selectively transmitting
Hak-Soon Lee, Sang-Shin Lee
doaj   +1 more source

Intrinsic, multiplexable sensors for electric field strength using structural slow light in phase-shifted fibre Bragg gratings [PDF]

, 2012
In this paper we demonstrate through simulation the potential for phase-shifted fibre Bragg gratings incorporating structural slow light to enable intrinsic reflection-mode point sensors for electric field or voltage.
Philip Orr, Niewczas, Pawel, Paweł Niewczas, Orr, Philip   +3 more
core   +1 more source

Mid-Infrared Grating Couplers for Silicon-on-Sapphire Waveguides

IEEE Photonics Journal, 2012
Theoretical and experimental results of mid-infrared (mid-IR) gratings for coupling between transverse-electric (TE)/transverse-magnetic (TM) mode silicon-on-sapphire (SOS) waveguides and zirconium, barium, lanthanum, aluminum, and sodium fluoride (ZBLAN)
Zhenzhou Cheng, Xia Chen, C. Y. Wong, Ke Xu, Christy K. Y. Fung, Y. M. Chen, Hon Ki Tsang   +6 more
doaj   +1 more source