SPONTANEOUS EMISSION OF NANO-ENGINEERED FLUOROPHORES IN PHOTONIC CRYSTALS

2006 ◽  
Vol 15 (01) ◽  
pp. 1-8 ◽  
Author(s):  
KAI SONG ◽  
RENAUD VALLEE ◽  
MARK VAN DER AUWERAER ◽  
KOEN CLAYS
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Point Source ◽  
Emission Spectrum ◽  
Spontaneous Emission ◽  
Transmission Spectrum ◽  
Photonic Bandgap ◽  
Middle Layer ◽  
Photonic Structure

The spontaneous emission of fluorophores embedded in a photonic crystal has been studied. By nano-engineering a sandwich-like photonic structure, such that fluorophore-coated photonic atoms constitute a middle layer between the photonic crystals, we have been able to precisely control the location of fluorophores in photonic crystals and exclude the presence of fluorophores at the surface of the crystal. It has been found that the stopband in the transmission spectrum is deeper than the stopband in the emission spectrum. We conjecture that the omnidirectional propagation of the emission from a point source in an incomplete photonic bandgap is the cause of the shallower stopband in emission.

scholarly journals Design of DNA Origami Diamond Photonic Crystals

2019 ◽  
Author(s):  
Sung Hun Park ◽  
Haedong Park ◽  
Kahyun Hur ◽  
Seungwoo Lee
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Volume Fraction ◽  
Photonic Bandgap ◽  
Building Blocks ◽  
Diamond Lattice ◽  
Dna Origami ◽  
Structural Constraints ◽  
Molding Process ◽  
Energy Devices

AbstractSelf-assembled photonic crystals have proven to be a fascinating class of photonic materials for non-absorbing structural colorizations over large areas and in diverse relevant applications, including tools for on-chip spectrometers and biosensors, platforms for reflective displays, and templates for energy devices. The most prevalent building blocks for the self-assembly of photonic crystals are spherical colloids and block copolymers (BCPs) due to the generic appeal of these materials, which can be crafted into large-area 3D lattices. However, due to the intrinsic limitations of these structures, these two building blocks are difficult to assemble into a direct rod-connected diamond lattice, which is considered to be a champion photonic crystal. Here, we present a DNA origami-route for a direct rod-connected diamond photonic crystal exhibiting a complete photonic bandgap (PBG) in the visible regime. Using a combination of electromagnetic, phononic, and mechanical numerical analyses, we identify (i) the structural constraints of the 50 megadalton-scale giant DNA origami building blocks that could self-assemble into a direct rod-connected diamond lattice with high accuracy, and (ii) the elastic moduli that are essentials for maintaining lattice integrity in a buffer solution. A solution molding process could enable the transformation of the as-assembled DNA origami lattice into a porous silicon- or germanium-coated composite crystal with enhanced refractive index contrast, in that a champion relative bandwidth for the photonic bandgap (i.e., 0.29) could become possible even for a relatively low volume fraction (i.e., 16 vol%).

NARROWING OF THE GAAS LED EMISSION SPECTRUM DUE TO THE USE OF THE INP (AG) LIGHT FILTER

2021 ◽  
Vol 13 (4) ◽  
pp. 32-38
Author(s):  
F. Makarenko ◽  
A. Arsent'ev ◽  
Konstantin Zolnikov
Keyword(s):  
Absorption Coefficient ◽  
Emission Spectrum ◽  
Band Gap ◽  
Spontaneous Emission ◽  
Transmission Spectrum ◽  
Spectral Dependence ◽  
Spectral Band ◽  
Light Filter ◽  
Spontaneous Emission Spectrum ◽  
High Degree

АЛ115В LED emission spectrum at currents of 6.3 mA and 56 mA, as well as the emission spectrum using an InP (Ag) light filter at current 56 mA, are studied. A classical approximation of the spontaneous emission spectrum of a straight-band LED is presented (without taking into account the narrowing of the band gap due to the high degree of LED doping). The analytical and experimental widths of the LED band gap are estimated. The transmission spectrum of an InP (Ag) light filter is presented, taking into account reflection losses in the region of fundamental transitions. The spectral dependence (fragment) of the InP absorption coefficient is determined. The error is estimated. It is proposed to use АЛ115В with an InP (Ag) light filter in order to narrow the spectral band of radiation from 53 nm to 34 nm.

Spontaneous Emission of a Two-Level Atom in Chiral Photonic Structures

2013 ◽  
Vol 446-447 ◽  
pp. 373-377
Author(s):  
Nurgül Akıncı
Keyword(s):  
Photonic Crystal ◽  
Emission Spectrum ◽  
Spontaneous Emission ◽  
Double Helix ◽  
Stop Band ◽  
Band Edge ◽  
Reflection Band ◽  
Spontaneous Emission Spectrum ◽  
One Dimensional ◽  
Level Atom

The spontaneous emission spectrum of a two-level atom in a one-dimensional (1D) anisotropic photonic crystal with symmetry of double helix is investigated using Laplace transform. Properties of spectrum of the radiation modes are discussed in detail under different values of detuning of atomic resonant frequency from a band-edge. Since spontaneous emission is proportional to the density of states (DOS), it is suppressed within the reflection band, corresponding to vanishing of the DOS. However, it is enhanced at the band edge. Therefore, spontaneous emission spectrum of the system is influenced at the edge of the stop band rather than at its centre.

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