| 1. |
- Benisty, H., et al.
(author)
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Low-loss photonic-crystal and monolithic InP integration : Bands, bends, lasers, filters
- 2004
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In: Photonic Crystal Materials and Devices II. - : SPIE - International Society for Optical Engineering. - 0819452688 ; , s. 119-128
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Conference paper (peer-reviewed)abstract
- Practical realizations of 2D (planar) photonics crystal (PhC) are either on a membrane or etched through a conventional heterostructure. While fascinating objects can emerge from the first approach, only the latter approach lends itself to a progressive integration of more compact PhC's towards monolithic PICs based on InP. We describe in this talk the various aspects from technology to functions and devices, as emerged from the European collaboration "PCIC". The main technology tour de force is deep-etching with aspect ratio of about 10 and vertical sidewall, achieved by three techniques (CAIBE, ICP-RIE, ECR-RIE). The basic functions explored are bends, splitters/combiners, mirrors, tapers, and the devices are filters and lasers. At the end of the talk, I will emphasize some positive aspects of "broad" multimode PhC waveguides, in view of compact add-drop filtering action, notably.
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| 2. |
- Benisty, H., et al.
(author)
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Models and measurements for the transmission of submicron-width waveguide bends defined in two-dimensional photonic crystals
- 2002
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In: IEEE Journal of Quantum Electronics. - 0018-9197 .- 1558-1713. ; 38:7, s. 770-785
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Journal article (peer-reviewed)abstract
- One of the essential building-blocks of miniature photonic crystal (PC)-based photonic integrated circuits (PICs) is the sharp bend. Our group has focused on the 2-D photonic crystal based on a triangular lattice of holes perforating a standard heterostructure. The latter, GaAlAs-based or InP-based, is vertically a monomode waveguide. We consider essentially one or two 60 bends defined by one to five missing rows, spanning both cases of monomode and multimode channel waveguides. From intensive modeling and various experimental measurements (both on GaAs and InP), we point out the origin of the present level of bend insertion losses and discuss the merits of the many roads open for improved design.
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| 3. |
- Ferrini, R., et al.
(author)
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Optical study of two-dimensional InP-based photonic crystals by internal light source technique
- 2002
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In: IEEE Journal of Quantum Electronics. - 0018-9197 .- 1558-1713. ; 38:7, s. 786-799
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Journal article (peer-reviewed)abstract
- We present the first optical study of 2-D photonic crystals (PCs) deeply etched in an InP/GaInAsP step-index waveguide. Following the same internal light source approach proposed by Labilloy and coworkers for the investigation of GaAs-based 2-D PCs, transmission measurements through simple PC slabs and 1-D Fabry-Perot (FP) cavities between PC mirrors were performed. Details are given on the experimental setup which has been implemented with respect to the original scheme and adapted to InP-based systems working at 1.5-mum. 2-D plane-wave expansion and finite difference time-domain (FDTD) methods are used to fit the experimental data. Out-of-plane losses were evaluated according to a recently introduced phenomenological model. In spite of the complex hole morphology in the measured samples, preliminary results are presented which indicate the possibility of separating different loss contributions from finite etch depth and hole shape. As for 1-D cavities, both FDTD and classical theory for planar resonators are applied in order to deduce the optical properties of the PC mirrors. The origin of an anomalously high transmission observed inside the stopgap is discussed and arguments are given to demonstrate the need for further modeling efforts when working in the bandgap regime.
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| 8. |
- Olivier, S., et al.
(author)
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Resonant and nonresonant transmission through waveguide bends in a planar photonic crystal
- 2001
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 79:16, s. 2514-2516
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Journal article (peer-reviewed)abstract
- We have measured the near-infrared transmission spectra of 60 degrees bends defined in two-dimensional photonic crystal waveguides consisting of three missing rows. Two limit cases are studied: a basic nonresonant bend and a bend built around a resonant lozenge cavity, which is found to exhibit peaked transmission. Finite-difference-time-domain simulations show very good agreement with the data allowing general design issues for efficient bends to be discussed.
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| 9. |
- Qiu, Min, et al.
(author)
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Photonic crystal optical filter based on contra-directional waveguide coupling
- 2003
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 83:25, s. 5121-5123
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Journal article (peer-reviewed)abstract
- Wavelength-selective operation of an optical filter (add/drop) based on a contra-directional photonic crystal waveguide coupler is demonstrated. The waveguides are defined as line defects in a two-dimensional triangular photonic crystal fabricated in an InP/GaInAsP heterostructure. The device is characterized using the end-fire method for the drop functionality. The experimental data are in good agreement with the theoretical results predicted by finite-difference time-domain simulations.
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| 10. |
- Back, M, et al.
(author)
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Leukotriene B4 is an indirectly acting vasoconstrictor in guinea pig aorta via an inducible type of BLT receptor
- 2004
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In: American journal of physiology. Heart and circulatory physiology. - : American Physiological Society. - 0363-6135 .- 1522-1539. ; 287:1, s. H419-H424
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Journal article (peer-reviewed)abstract
- Leukotriene B4(LTB4) is a potent leukocyte chemoattractant recently implicated in the pathogenesis of atherosclerosis. The aim of this study was to assess the effects of LTB4on isolated aortic preparations. Rings of guinea pig aorta were challenged with LTB4for recording mechanical responses and measurements of mediator release, and LTB4receptor (BLT1) expression was assessed by RT-PCR. Single concentrations of LTB4induced concentration-dependent contractions that were inhibited by treatment with antihistamines, indomethacin, or the thromboxane receptor antagonist BAYu3405 as well as by denudation of endothelium. In addition, LTB4increased the release of histamine and thromboxane in the bath. The contractions induced by LTB4were inhibited by either the unselective BLT receptor antagonist ONO-4057 or the selective BLT1receptor antagonist U-75302. Pretreatment with all -trans-retinoic acid enhanced the contractions and the release of histamine induced by LTB4, without affecting either the contractions induced by histamine or the histamine release evoked by calcium ionophore A23187. Analysis by RT-PCR indicated the expression of a BLT1receptor in the guinea pig aorta and that BLT1receptor mRNA was upregulated after treatment with retinoic acid. These results suggest that LTB4contracts the guinea pig aorta via an indirect mechanism involving the release of histamine and thromboxane and that this BLT1receptor-mediated response can be upregulated by all -trans-retinoic acid.
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