All-optical tunable slow light achievement in photonic crystal coupled-cavity waveguides

Abstract

In this paper, a tunable low power slow light photonic crystal device with a silicon-on-insulator platform is proposed based on the combination of an asymmetric defects coupled-cavity waveguide and the electromagnetically induced transparency (EIT) phenomenon. Modulating the refractive index of special regions in the suggested structure by the EIT phenomenon leads to a relatively wideband slow light device with adjustable group index in the same structure. Using this feature, a small and compact delay line is introduced that has many applications in optical telecommunications, especially in buffers. The numerical calculations show that the group index of 80-98 over the slow light bandwidth from 3.2 to 2.6 nm is achievable for the central wavelength of 1546-1555 nm, respectively. The device malfunction, due to fabrication errors, is modeled, and the tunable characteristics of the proposed structure are verified.

Slow light in ellipse-hole photonic crystal line-defect waveguide with high normalized delay bandwidth product

“…In our structure, it is possible to minimize the effects of imperfections by further correction methods. Various methods have been studied and used to dynamically tune the properties of silicon PC devices by an external control, such as electro-optic effect [13], electromagnetically induced transparency [15], microfluidic infiltration [29], and thermal tuning [39]. Using these tuning methods we can modify the properties of the silicon waveguide or silica region in the presented structure so that the NDBP parameter is close to the previous optimized value.…”

“…The two basic kinds of PC structures, including line-defect waveguides [8,9] and coupled-cavity waveguides [10][11][12][13][14][15], have been used to achieve slow light. Within the past years, PC slow light structures mostly have been presented based on linedefect waveguides, which are suitable for enhanced lightmatter interactions.…”

Demonstration of a noble all optical D‐type flip flop system for high speed data processing

“…The optical buffer is the key element for all optical data processing and optical packet switched networks (OPSN). Many types of all optical buffer has been proposed using recirculated loop or slow light waveguides [3][4][5][6]. But all optical buffers suffer from increasing propagation time, and optical attenuation within the circulating light path.…”

“…However, these methods using multi-layer structure result in drawbacks such as complexed fabrication, increased weight, bulky size, and misalignment. Other approaches using multiresonance elements [4][5][6][7] achieve linear phase response but still use an air gap or a dielectric layer which can contribute to the linear response. Three element types, square patch, square ring and ring-loaded patch, are used to increase achievable phase range on a single layer, but the phase responses are not nonlinear [8].…”

Slow Light with High Normalized Delay Bandwidth Product in Photonic Crystal Line Defect Waveguide

“…In order to achieve slow light in photonic crystal structure two basic forms have been used: linedefect waveguides [11,12] and coupled-cavity waveguides [13][14][15][16][17][18]. In recent years, slow light based on line defect waveguide has attracted much attention.…”