Coupling length variation and multi-wavelength demultiplexing in photonic crystal waveguides

Abstract

In this Letter, the effects of material/structure parameters of photonic crystal (PhC) parallel waveguides on the coupling length are investigated. The results show that, increasing the effective relative permittivity of the PhC leads to a downward shift of the photonic bandgap and a variation of the coupling length. A compact PhC 1.31/1.55 μm wavelength division multiplexer (WDM)/demultiplexer with simple structure is proposed, where the output power ratios are more than 24 dB. This WDM can multiplex/demultiplex other light waves efficiently.

1D reconfigurable bistable photonic device composed of phase change material for detection of reproductive female hormones

“…FOM can be obtained by using following relation The evaluation of the performance of the proposed 1D photonic biosensor (PQ) 5 GDG(PQ) 5 loaded with blood samples containing progesterone and estradiol reproductive hormones of different concentration under crystalline and amorphous phases of GST has been done by calculating S, Q and FOM values of designs depending upon change in internal external parameters of the design. The numerical values of S, Q and FOM of design under crystalline and amorphous phases have been obtained by using relations (12) to (14) and are listed in table 1 to table 8. Tables 1-4 are summarizing the calculated results of the design corresponding to blood sample with progesterone hormone of concentration 0, 60 nmol l −1 , 80 nmol l −1 and 100 nmol l −1 at incident angle 0°and defect layer thickness 320 nm and 380 nm under crystalline and amorphous phases of GST.…”

“…These structures provide a powerful platform for designing of photonic devices which could find diverse range of optical and technological applications owing to tremendous ability of manipulating amplitude, polarization and phase of electromagnetic waves [3][4][5]. The landmark achievements of two renowned scientists Yablonovitch and John who discovered photonic crystals (PCs) in 1987 [6,7] open a door for developing engineered photonic devices like topological waveguides [8], photonic crystal fibers [9], high efficiency LEDs [10], absorbers [11], optical couples [12] and photonic biosensors of high sensitivity and resolution [13][14][15]. Unfortunately most of these devices are made up of passive components and have fixed optical response which gradually impeded their technological use especially in the optoelectronic and integrated photonics where active optical properties are essential requirements [16].…”

“…Motivated by aforementioned piece of excellent research work [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and importance of GST material [26][27][28][29][30][31][32] in this manuscript 1D photonic biosensor capable of detecting minute refractive index changes in blood samples containing progesterone and estradiol reproductive hormones of different concentration levels in presence of cGST and aGST phases of Ge 2 Sb 2 Te 5 material, has been studied. This design successfully measures the shift in location of the defect mode within PBG of proposed structure depending upon respective change in refractive index of blood samples containing reproductive hormones under cGST and aGST phases both, of Ge 2 Sb 2 Te 5 material.…”

One-way rotating state of multi-periodicity frequency bands in circular photonic crystal

“…Due to the characteristics of photonic band gap (PBG) and the localization [1][2][3], the light can be captured and guided in PC. PC has been extensively researched in the field of optics, including optical fiber [4][5][6][7][8][9][10][11][12], coupler [13,14], filter [5,15], sensor [9,12,16,17], laser [18], lens [19][20][21][22][23][24][25][26], waveguide [27], etc. In 2005, Haldane and Raghu theor etically proposed the one-way electromagnetic modes [28] in two-dimensional magnetic PC similar to the chiral edge state of quantum hall (QH) effect, and opened the prelude to the research of topological photonics and one-way state in PC.…”

Multiband super-resolution imaging of graded-index photonic crystal flat lens

“…The ordered structure arrangement makes the PCs characterized with the features such as photonic band gap, photonic localization and negative refraction. The characteristics of PCs could provide wide primary prospect in optical communication and optical integrated systems, including fibers [3][4][5][6][7][8][9], filters [10], prisms [11,12], waveguides [13] and lenses [14][15][16][17][18][19][20].…”