Design of compact narrowband optical filter on SOI using asymmetric directional coupler
TL;DR: In this paper, a narrowband optical filter on Silicon-on-Insulator based on a directional coupler of continuous and periodic segmented waveguide is theoretically investigated, and it is shown that the filtering a...
Abstract: A narrowband optical filter on Silicon-on-Insulator based on a directional coupler of continuous and periodic segmented waveguide is theoretically investigated. The study shows that the filtering a...
Citations
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TL;DR: In this paper, a segmented silicon based multimode to dual port slot structure on silicon-on-insulator platform is proposed which can be used as a refractive index sensing device.
Abstract: A segmented silicon based multimode to dual port slot structure on silicon-on-insulator platform is proposed which can be used as a refractive-index sensing device. The introduction of segmentation leads to tuning the effective index of the device which results in increasing compactness of the sensing device. Although the structure supporting TM mode is more compact than TE mode, but TE mode is considered here as vertical slots in the output section enhances optical signal in the slots for TE mode only. By considering dual output, the device length is reduced further as dual self-imaging length is less compared to single self-imaging distance for symmetrical multimode section input. The surface sensitivity of the structure has a typical value of∼2249 nm/RIU. Relative sensitivity can be calculated from the ratio of field amplitudes of the arms of the dual output. Matrix method and 2D FDTD is used for the entire analysis.
2 citations
References
More filters
TL;DR: It is shown that by use of a novel waveguide geometry the field can be confined in a 50-nm-wide low-index region with a normalized intensity of 20 microm(-2), approximately 20 times higher than what can be achieved in SiO2 with conventional rectangular waveguides.
Abstract: We present a novel waveguide geometry for enhancing and confining light in a nanometer-wide low-index material. Light enhancement and confinement is caused by large discontinuity of the electric field at highindex-contrast interfaces. We show that by use of such a structure the field can be confined in a 50-nm-wide low-index region with a normalized intensity of 20 mm 22 . This intensity is approximately 20 times higher than what can be achieved in SiO2 with conventional rectangular waveguides. © 2004 Optical Society of America OCIS codes: 030.4070, 130.0130, 130.2790, 230.7370, 230.7380, 230.7390, 230.7400. Recent results in integrated optics have shown the ability to guide, bend, split, and f ilter light on chips by use of optical devices based on high-index-contrast waveguides. 1–5 In all these devices the guiding mechanism is based on total internal ref lection (TIR) in a highindex material (core) surrounded by a low-indexmaterial (cladding); the TIR mechanism can strongly confine light in the high-index material. In recent years a number of structures have been proposed to guide or enhance light in low-index materials, 6–1 1 relying on external ref lections provided by interference effects. Unlike TIR, the external ref lection cannot be perfectly unity; therefore the modes in these structures are inherently leaky modes. In addition, since interference is involved, these structures are strongly wavelength dependent. Here we show that the optical field can be enhanced and conf ined in the low-index material even when light is guided by TIR. For a high-index-contrast interface, Maxwell’s equations state that, to satisfy the continuity of the normal component of electric f lux density D, the corresponding electric field (E-field) must undergo a large discontinuity with much higher amplitude in the low-index side. We show that this discontinuity can be used to strongly enhance and confine light in a nanometer-wide region of low-index material. The proposed structure presents an eigenmode, and it is compatible with highly integrated photonics technology. The principle of operation of the novel structure can be illustrated by analysis of the slab-based structure shown in Fig. 1(a), where a low-index slot is embedded between two high-index slabs (shaded regions). The novel structure is hereafter referred to as a slot waveguide. The slot waveguide eigenmode can be seen as being formed by the interaction between the fundamental eigenmodes of the individual slab waveguides. Rigorously, the analytical solution for the transverse E-field profile Ex of the fundamental TM eigenmode of the slab-based slot waveguide is
1,716 citations
Book•
28 Dec 1983
TL;DR: The Wiley Classics Library as discussed by the authors consists of selected books that have become recognized classics in their respective fields with these new unabridged and inexpensive editions, Wiley hopes to extend the life of these important works by making them available to future generations of mathematicians and scientists.
Abstract: The Wiley Classics Library consists of selected books that have become recognized classics in their respective fields With these new unabridged and inexpensive editions, Wiley hopes to extend the life of these important works by making them available to future generations of mathematicians and scientists
1,069 citations
TL;DR: A novel silicon waveguide structure for guiding and confining light in nanometer-wide low-refractive-index material is experimentally demonstrated and it is shown that the structure can be implemented in highly integrated photonics.
Abstract: We experimentally demonstrate a novel silicon waveguide structure for guiding and confining light in nanometer-wide low-refractive-index material. The optical field in the low-index material is enhanced because of the discontinuity of the electric field at high-index-contrast interfaces. We measure a 30% reduction of the effective index of light propagating in the novel structure due to the presence of the nanometer-wide low-index region, evidencing the guiding and confinement of light in the low-index material. We fabricate ring resonators based on the structure and show that the structure can be implemented in highly integrated photonics.
678 citations
TL;DR: In this article, the effect of miniaturization and surface roughness on transmission losses within a Si/SiO2 waveguide system, and explain the results using a theoretical model was evaluated.
Abstract: In this letter, we experimentally evaluate the effect of miniaturization and surface roughness on transmission losses within a Si/SiO2 waveguide system, and explain the results using a theoretical model. Micrometer/nanometer-sized waveguides are imperative for its potential use in dense integrated optics and optical interconnection for silicon integrated circuits. A theoretical model was employed to predict the relationship between the transmission losses of the dielectric silicon waveguide and its width. This model accurately predicts that loss increases as waveguide width decreases. Furthermore, we show that a major source of loss comes from sidewall roughness. We have constructed a complete contour map showing the interdependence of sidewall roughness and transmission loss, to assist users in their design of an optimal waveguide fabrication process that minimizes loss. Additionally, users can find an effective path to reduce the scattering loss from sidewall roughness. Using this map, we confirm that n...
503 citations
TL;DR: Coupled waveguide structures with sections of alternating phase mismatch are proposed as switched directional coupler configurations in which complete conversion of light from one guide to the other can be achieved by an electrical adjustment.
Abstract: Coupled waveguide structures with sections of alternating phase mismatch are proposed as switched directional coupler configurations in which complete conversion of light from one guide to the other can be achieved by an electrical adjustment. These structures can be used to make electrooptic switches and amplitude modulators in integrated optics form with improved conversion and on-off ratios. Couplers with 2, 3, 4, and N sections of alternating phase mismatch are analyzed, and diagrams describing their switching characteristics are given.
498 citations