SELF-GUIDING IN LOW-INDEX-CONTRAST PLANAR PHOTONIC CRYSTALS

This paper presents a new lateral confinement mechanism based on the self-collimation effect in planar photonic crystals (PhCs). In this mechanism, planar PhCs with approximately flat equifrequency contours (EFCs) are utilized for laterally confining the light and total internal reflection (TIR) is used for the vertical confinement. Since this mechanism relies on dispersion engineering, no photonic band gap nor defect modes are required. Using this approach, it is possible to engineer flat EFCs completely below the light cone using relatively low-index-contrast material systems. Therefore, in this work we first engineer a low-index-contrast planar PhC with approximately flat EFCs in the first band, which is always below the light cone. Then, we investigate the lateral divergence of self-guided beams in this structure using the plane wave method (PWM). It is found that light with a narrow band frequency in the first band can be very well self-confined laterally.

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Controlling emission using one dimensional integrated photonic fluorescent collectors

MRS Advances ◽

10.1557/adv.2015.39 ◽

2015 ◽

Vol 1 (59) ◽

pp. 3909-3914

Author(s):

Thomas S. Parel ◽

Tomas Markvart

Keyword(s):

Photonic Crystals ◽

Band Gap ◽

Total Internal Reflection ◽

Photonic Band Gap ◽

Edge Emission ◽

Photon Transport ◽

One Dimensional ◽

Fabry Perot ◽

Fluorescent Molecules ◽

Photonic Band

ABSTRACTIt is known that photonic crystals can be used to suppress spontaneous emission. This property of photonic crystals has been investigated for suppressing and decreasing the propagation of photons within loss cones in fluorescent collectors. Fluorescent collectors can concentrate light onto solar cells by trapping fluorescence through total internal reflection. In an ideal fluorescent collector the major obstacle to efficient photon transport is the loss of photons through the top and bottom escape cones. One possible method to decrease this loss and improve the efficiency of these devices is to fabricate one-dimensional photonic crystals doped with fluorescent molecules. If these photonic crystals are tuned to exhibit a photonic band gap in the escape cone directions and at the emission frequencies of the fluorescent molecules, a suppression of the escape cone emission and an enhancement of the edge emission is expected. In this paper, we detail the fabrication of a one dimensional integrated photonic collector and show the suppression of the escape cone emission. This suppression of the escape cone will be shown to correspond to the photonic band gap and the modifications to the edge emission will be shown to correspond well with so called Fabry Perot modes. The control of emission inside fluorescent collectors opens up a number of additional possibilities for efficiency enhancements that will also be discussed.

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3-Dimensional Photonic Crystals at Optical Wavelengths

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863598000168 ◽

1998 ◽

Vol 07 (02) ◽

pp. 181-200 ◽

Cited By ~ 13

Author(s):

S. G. Romanov

Keyword(s):

Photonic Crystals ◽

Band Gap ◽

Photonic Band Gap ◽

Stop Band ◽

High Refractive Index ◽

3 Dimensional ◽

Optical Wavelength ◽

Photonic Band Gap Materials ◽

Optical Wavelengths ◽

Photonic Band

Different experimental strategies towards the 3-dimensional photonic crystals operating at optical wavelength are classified. The detailed discussion is devoted to the recent progress in photonic crystals fabricated by template method — the photonic band gap materials on the base of opal. The control of photonic properties of opal-based gratings is achieved through impregnating the opal with high refractive index semiconductors and dielectrics. Experimental study demonstrated the dependence of the stop band behaviour upon the type of impregnation (complete or partial) and showed a way for approaching complete photonic band gap. The photoluminescence from opal- semiconductor gratings revealed suppression of spontaneous emission in the gap region with following enhancement of the emission efficiency at the low-energy edge of the gap.

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Omnidirectional Photonic Band Gap Broadening in One dimensional Photonic Crystals

2006 International Symposium on Biophotonics, Nanophotonics and Metamaterials ◽

10.1109/metamat.2006.334924 ◽

2006 ◽

Author(s):

Li Changhong ◽

Tian Huiping ◽

Ji Yuefeng ◽

Liu Hai

Keyword(s):

Photonic Crystals ◽

Band Gap ◽

Photonic Band Gap ◽

One Dimensional ◽

Omnidirectional Photonic Band Gap ◽

Photonic Band

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One dimensional graphene based photonic crystals: Graphene stacks with sequentially-modulated doping for photonic band gap tailoring

Superlattices and Microstructures ◽

10.1016/j.spmi.2017.09.012 ◽

2017 ◽

Vol 112 ◽

pp. 46-56 ◽

Cited By ~ 10

Author(s):

I. Fuentecilla-Carcamo ◽

M. Palomino-Ovando ◽

F. Ramos-Mendieta

Keyword(s):

Photonic Crystals ◽

Band Gap ◽

Photonic Band Gap ◽

One Dimensional ◽

Band Gap Tailoring ◽

Photonic Band

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Titania Photonic Crystals with Precise Photonic Band Gap Position via Anodizing with Voltage versus Optical Path Length Modulation

Nanomaterials ◽

10.3390/nano9040651 ◽

2019 ◽

Vol 9 (4) ◽

pp. 651 ◽

Cited By ~ 7

Author(s):

Ermolaev ◽

Kushnir ◽

Sapoletova ◽

Napolskii

Keyword(s):

Refractive Index ◽

Photonic Crystals ◽

Band Gap ◽

Titanium Oxide ◽

Effective Refractive Index ◽

Photonic Band Gap ◽

Voltage Versus ◽

Research Attention ◽

Anodic Titanium Oxide ◽

Photonic Band

Photonic crystals based on titanium oxide are promising for optoelectronic applications, for example as components of solar cells and photodetectors. These materials attract great research attention because of the high refractive index of TiO2. One of the promising routes to prepare photonic crystals based on titanium oxide is titanium anodizing at periodically changing voltage or current. However, precise control of the photonic band gap position in anodic titania films is a challenge. To solve this problem, systematic data on the effective refractive index of the porous anodic titanium oxide are required. In this research, we determine quantitatively the dependence of the effective refractive index of porous anodic titanium oxide on the anodizing regime and develop a model which allows one to predict and, therefore, control photonic band gap position in the visible spectrum range with an accuracy better than 98.5%. The prospects of anodic titania photonic crystals implementation as refractive index sensors are demonstrated.

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