scholarly journals Time-Resolved FDTD and Experimental FTIR Study of Gold Micropatch Arrays for Wavelength-Selective Mid-Infrared Optical Coupling

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5203
Author(s):  
Ying Fu ◽  
Tom Yager ◽  
George Chikvaidze ◽  
Srinivasan Iyer ◽  
Qin Wang
Keyword(s):  
Near Field ◽  
Fdtd Method ◽  
Single Layer ◽  
Optical Coupling ◽  
Time Duration ◽  
Time Resolved ◽  
Mid Infrared ◽  
Precision Design ◽  
Surface Metal ◽  
Patch Length

Infrared radiation reflection and transmission of a single layer of gold micropatch two-dimensional arrays, of patch length ∼1.0 μm and width ∼0.2 μm, have been carefully studied by a finite-difference time-domain (FDTD) method, and Fourier-transform infrared spectroscopy (FTIR). Through precision design of the micropatch array structure geometry, we achieve a significantly enhanced reflectance (85%), a substantial diffraction (10%), and a much reduced transmittance (5%) for an array of only 15% surface metal coverage. This results in an efficient far-field optical coupling with promising practical implications for efficient mid-infrared photodetectors. Most importantly we find that the propagating electromagnetic fields are transiently concentrated around the gold micropatch array in a time duration of tens of ns, providing us with a novel efficient near-field optical coupling.

Dirac Surface Plasmons in Photoexcited Bismuth Telluride Nanowires : Optical Pump-Terahertz Probe Spectroscopy

Nanoscale ◽  
2021 ◽  
Author(s):  
Mithun K P ◽  
Srabani Kar ◽  
Abinash Kumar ◽  
Victor Suvisesha Muthu Dharmaraj ◽  
Ravishankar Narayanan ◽  
...  
Keyword(s):  
Surface Plasmons ◽  
Bismuth Telluride ◽  
Topological Insulators ◽  
Collective Excitation ◽  
Optical Pump ◽  
Time Resolved ◽  
Mid Infrared ◽  
Plasmonic Materials ◽  
Probe Spectroscopy

Collective excitation of Dirac plasmons in graphene and topological insulators have opened new possibilities of tunable plasmonic materials ranging from THz to mid-infrared regions. Using time resolved Optical Pump -...

scholarly journals Two - Color Mid-Infrared Spectroscopy of Isoelectronic Centers in Silicon

2003 ◽  
Vol 770 ◽  
Author(s):  
N.Q. Vinh ◽  
T. Gregorkiewicz
Keyword(s):  
Excited States ◽  
Free Electron ◽  
Free Electron Laser ◽  
Materials Science ◽  
Time Resolved ◽  
Mid Infrared ◽  
Semiconductor Physics ◽  
Open Questions ◽  
Time Resolved Photoluminescence ◽  
Tunable Source

AbstractOne of the open questions in semiconductor physics is the origin of the small splittings of the excited states of bound excitons in silicon. A free electron laser as a tunable source of the mid-infrared radiation (MIR) can be used to investigate such splittings of the excited states of optical centers created by transition metal dopants in silicon. In the current study, the photoluminescence from silver and copper doped silicon is investigated by two color spectroscopy in the visible and the MIR. It is shown the PL due recombination of exciton bound to Ag and Cu is quenched upon application of the MIR beam. The time-resolved photoluminescence measurements and the quenching effects of these bands are presented. By scanning the wavelength of the free-electron laser ionization spectra of relevant traps involved in photoluminescence are obtained. The formation and dissociation of the bound excitons, and the small splittings of the effective-mass excited states are discussed. The applied experimental method allows correlation of DLTS data on trapping centers to specific channels of radiative recombination. It can be applied for spectroscopic analysis in materials science of semicondutors.

scholarly journals Mid-infrared time-resolved photoconduction in black phosphorus

2D Materials ◽  
2016 ◽  
Vol 3 (4) ◽  
pp. 041006 ◽  
Author(s):  
Ryan J Suess ◽  
Edward Leong ◽  
Joseph L Garrett ◽  
Tong Zhou ◽  
Reza Salem ◽  
...  
Keyword(s):  
Black Phosphorus ◽  
Time Resolved ◽  
Mid Infrared

Trapping of Nano-Particles Using a Near-Field Optical Fiber Probe

2012 ◽  
Vol 516 ◽  
pp. 90-95
Author(s):  
Bing Hui Liu ◽  
Li Jun Yang ◽  
Yang Wang
Keyword(s):  
Near Field ◽  
Fdtd Method ◽  
Laser Wavelength ◽  
Nano Particles ◽  
Minimum Size ◽  
Fiber Probe ◽  
Circular Shape ◽  
Optical Fiber Probe ◽  
Fibre Probe ◽  
Difference Time

By employing a generalization of the conservation law for momentum using the finite difference time domain (FDTD) method, the feasibility of using a near-field optical fibre probe to create near-field optical trapping is investigated. Numerical results indicate that the scheme is able to trap nanoparticles with diameters of tens of nanometres in a circular shape with lower laser intensity. Using the built system with a tapered metal-coated fibre probe, 120 nm polystyrene particles are trapped in a multi-circular shape with a minimum size of 400 nm. They are at a resolution of λ/7 (λ: laser wavelength) and d (d: tip diameter of fiber probe), respectively.

Tin diselenide van der Waals materials as new candidates for mid-infrared waveguide chips

Nanoscale ◽  
2019 ◽  
Vol 11 (30) ◽  
pp. 14113-14117 ◽  
Author(s):  
Mengfei Xue ◽  
Qi Zheng ◽  
Runkun Chen ◽  
Lihong Bao ◽  
Shixuan Du ◽  
...  
Keyword(s):  
Near Field ◽  
Van Der Waals ◽  
Building Blocks ◽  
Two Dimensional ◽  
Mid Infrared ◽  
Near Field Imaging ◽  
Van Der Waals Materials ◽  
Field Imaging

Near-field imaging of mid-infrared waveguide in SnSe2 slabs promotes two-dimensional van der Waals materials as building blocks for integrated MIR chips.

scholarly journals BaF2 Ridge Waveguide Operating at Mid-Infrared Wavelength

2021 ◽  
Vol 9 ◽  
Author(s):  
Yazhou Cheng ◽  
Xinbin Zhang ◽  
Hongxiao Song
Keyword(s):  
Ion Irradiation ◽  
Lattice Structure ◽  
Near Field ◽  
Annealing Treatment ◽  
Femtosecond Laser Ablation ◽  
Ridge Waveguide ◽  
Propagation Loss ◽  
Mid Infrared ◽  
Infrared Wavelength ◽  
Coupling System

We report on the fabrication of optical ridge waveguide in barium fluoride (BaF2) crystal by 15 MeV C5+ ions irradiation with femtosecond laser ablation. The near-field modal profile and propagation loss of the waveguide at mid-infrared wavelength 4 µm are investigated by using end-face coupling system. We implement a series of annealing treatment and it efficiently reduces the propagation loss of the waveguide. The confocal Raman spectra demonstrate that the lattice structure of BaF2 crystal does not change largely after C5+ ion irradiation.

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