scholarly journals Silicon Nitride Photonic Crystal Free-Standing Membranes: A Flexible Platform for Visible Spectral Range Devices

10.5772/54846 ◽  
2013 ◽  
Author(s):  
T. Stomeo ◽  
A. Qualtieri ◽  
F. Pisanello ◽  
L. Martiradonna ◽  
P.P. Pompa ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Silicon Nitride ◽  
Spectral Range ◽  
Visible Spectral Range ◽  
Free Standing

scholarly journals Natural slab photonic crystals in centric diatoms

2019 ◽  
Author(s):  
Johannes W. Goessling ◽  
William P. Wardley ◽  
Martin Lopez Garcia
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Spectral Range ◽  
Near Infrared ◽  
Light Regulation ◽  
Visible Spectral Range ◽  
Mating Strategies ◽  
Unit Cell ◽  
Critical Parameters ◽  
Centric Diatom

AbstractNatural photonic crystals can serve in mating strategies or as aposematism for animals, but they also exist in some photosynthetic organisms, with potential implications for their light regulation. Some of the most abundant microalgae, named diatoms, evolved a silicate exoskeleton, the frustule, perforated with ordered pores resembling photonic crystals. Here we present the first combined experimental and theoretical characterization of the photonic properties of the diatom girdle, i.e. one of two structures assembling the frustule. We show that the girdle of the centric diatom Coscinodiscus granii is a well-defined slab photonic crystal, causing, under more natural conditions when immersed in water, a pseudogap for modes in the near infrared. The pseudogap disperses towards the visible spectral range when light incides at larger angles. The girdle crystal structure facilitates in-plane propagation for modes in the green spectral range. We demonstrate that the period of the unit cell is one of the most critical factors for causing these properties. The period is shown to be similar within individuals of a long-term cultivated inbred line and between 4 different C. granii cell culture strains. In contrast, the pore diameter had negligible effects upon the photonic properties. We hence propose that critical parameters defining the photonic response of the girdle are highly preserved. Other centric diatom species, i.e. Thalasiosira pseudonana, C. radiatus and C. wailesii, present similar unit cell morphologies with various periods in their girdles. We speculate that evolution has preserved the photonic crystal character of the centric girdle, indicating an important biological functionality for this clade of diatoms.

scholarly journals Silicon nitride PhC nanocavities as versatile platform for visible spectral range devices

2012 ◽  
Vol 10 (3) ◽  
pp. 319-324 ◽  
Author(s):  
F. Pisanello ◽  
L. Martiradonna ◽  
A. Qualtieri ◽  
T. Stomeo ◽  
M. Grande ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Spectral Range ◽  
Visible Spectral Range

scholarly journals Thermo-optical response of photonic crystal cavities operating in the visible spectral range

2013 ◽  
Vol 24 (31) ◽  
pp. 315204 ◽  
Author(s):  
Janik Wolters ◽  
Niko Nikolay ◽  
Max Schoengen ◽  
Andreas W Schell ◽  
Jürgen Probst ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Spectral Range ◽  
Optical Response ◽  
Visible Spectral Range ◽  
Photonic Crystal Cavities

scholarly journals Supercontinuum Generation in the Cladding Modes of an Endlessly Single-Mode Fiber

2019 ◽  
Vol 9 (20) ◽  
pp. 4428 ◽  
Author(s):  
Tobias Baselt ◽  
Bryan Nelsen ◽  
Andrés Fabián Lasagni ◽  
Peter Hartmann
Keyword(s):  
Photonic Crystal ◽  
Spectral Range ◽  
Short Pulse ◽  
Group Velocity Dispersion ◽  
Damage Threshold ◽  
Nonlinear Effects ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Visible Spectral Range ◽  
The Core

In photonic crystal fibers, light guidance can be achieved by a central defect of a periodic structure of air holes in a silica glass matrix and the dispersion can be adjusted over a wide spectral range to enhance nonlinear effects. By coupling short pulse laser radiation into the core with tight confinement and utilizing the nonlinear properties of glass, this radiation can be converted to a broad spectral distribution. The tight confinement puts limits on the maximum pulse fluence propagating in the core due to the damage threshold of the glass. Therefore, when higher power spectral densities are desired, it is favorable to spread the generation of light over a much larger area to prevent fiber damage. We present here a method for generating a supercontinuum using the cladding modes of an endlessly single-mode fiber. These modes generate a supercontinuum utilizing a multimodal quasi-continuum of states, for which dispersion is governed by the guiding properties of the material between the air-filled holes in the cladding. The system also provides experimental access to unique phenomena in nonlinear optics. Simulations of the propagation properties of the core mode and cladding modes were compared with measurements of the group-velocity dispersion in a modified white-light Mach–Zehnder interferometer. The coupling of similar laser parameters into the cladding of the photonic crystal fiber enables a significant increase in conversion efficiency in the visible spectral range compared with the core-pumped case.

scholarly journals MoS2 Based Photodetectors: A Review

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2758
Author(s):  
Alberto Taffelli ◽  
Sandra Dirè ◽  
Alberto Quaranta ◽  
Lucio Pancheri
Keyword(s):  
Electric Fields ◽  
Spectral Range ◽  
Performance Metrics ◽  
Transition Metal Dichalcogenides ◽  
Visible Spectral Range ◽  
Detector Performance ◽  
Strong Light ◽  
Near Ultraviolet ◽  
Passivation Layers ◽  
Low Dimensional

Photodetectors based on transition metal dichalcogenides (TMDs) have been widely reported in the literature and molybdenum disulfide (MoS2) has been the most extensively explored for photodetection applications. The properties of MoS2, such as direct band gap transition in low dimensional structures, strong light–matter interaction and good carrier mobility, combined with the possibility of fabricating thin MoS2 films, have attracted interest for this material in the field of optoelectronics. In this work, MoS2-based photodetectors are reviewed in terms of their main performance metrics, namely responsivity, detectivity, response time and dark current. Although neat MoS2-based detectors already show remarkable characteristics in the visible spectral range, MoS2 can be advantageously coupled with other materials to further improve the detector performance Nanoparticles (NPs) and quantum dots (QDs) have been exploited in combination with MoS2 to boost the response of the devices in the near ultraviolet (NUV) and infrared (IR) spectral range. Moreover, heterostructures with different materials (e.g., other TMDs, Graphene) can speed up the response of the photodetectors through the creation of built-in electric fields and the faster transport of charge carriers. Finally, in order to enhance the stability of the devices, perovskites have been exploited both as passivation layers and as electron reservoirs.

Asymmetric Free-Standing 2-D Photonic Crystal Films and Their Janus Particles

2013 ◽  
Vol 135 (30) ◽  
pp. 11397-11401 ◽  
Author(s):  
Jian-Tao Zhang ◽  
Xing Chao ◽  
Sanford A. Asher
Keyword(s):  
Photonic Crystal ◽  
Janus Particles ◽  
Free Standing ◽  
Crystal Films
Sign in / Sign up

Export Citation Format

Share Document