اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدUltrafast polarization conversion with plasmonic crystals
349
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Femtosecond-scale polarization state conversion is experimentally found in optical response of a plasmonic nanograting by means of time-resolved polarimetry. Simultaneous measurements of the Stokes parameters as a function of time with an averaging time-gate of 130 fs reveal a remarkable alteration of polarization state inside a single fs-pulse reflected from a plasmonic crystal. Time-dependent depolarization is experimentally found and described within an analytical model which predicts the four-fold enhancement of the polarization conversion effect with the use of the narrower gate. The effect is attributed to excitation of time-delayed polarization-sensitive surface plasmons with a highly birefringent Fano-type spectral profile.
قيم البحث
اقرأ أيضاً
Efficient frequency conversion techniques are crucial to the development of plasmonic metasurfaces for information processing and signal modulation. In principle, nanoscale electric-field confinement in nonlinear materials enables higher harmonic con
version efficiencies per unit volume than those attainable in bulk materials. Here we demonstrate efficient second-harmonic generation (SHG) in a serrated nanogap plasmonic geometry that generates steep electric field gradients on a dielectric metasurface. An ultrafast pump is used to control plasmon-induced electric fields in a thin-film material with inversion symmetry that, without plasmonic enhancement, does not exhibit an an even-order nonlinear optical response. The temporal evolution of the plasmonic near-field is characterized with ~100as resolution using a novel nonlinear interferometric technique. The ability to manipulate nonlinear signals in a metamaterial geometry as demonstrated here is indispensable both to understanding the ultrafast nonlinear response of nanoscale materials, and to producing active, optically reconfigurable plasmonic devices
We present a simple yet elegant Mueller matrix approach for controlling the Fano interference effect and engineering the resulting asymmetric spectral line shape in anisotropic optical system. The approach is founded on a generalized model of anisotr
opic Fano resonance, which relates the spectral asymmetry to two physically meaningful and experimentally accessible parameters of interference, namely, the Fano phase shift and the relative amplitudes of the interfering modes. The differences in these parameters between orthogonal linear polarizations in an anisotropic system are exploited to desirably tune the Fano spectral asymmetry using pre- and post-selection of optimized polarization states. Experimental control on the Fano phase and the relative amplitude parameters and resulting tuning of spectral asymmetry is demonstrated in waveguided plasmonic crystals using Mueller matrix-based polarization analysis. The approach enabled tailoring of several exotic regimes of Fano resonance including the complete reversal of the spectral asymmetry. The demonstrated control and the ensuing large tunability of Fano resonance in anisotropic systems shows potential for Fano resonance-based applications involving control and manipulation of electromagnetic waves at the nano scale.
Coherent broadband excitation of plasmons brings ultrafast photonics to the nanoscale. However, to fully leverage this potential for ultrafast nanophotonic applications, the capacity to engineer and control the ultrafast response of a plasmonic syste
m at will is crucial. Here, we develop a framework for systematic control and measurement of ultrafast dynamics of near-field hotspots. We show deterministic design of the coherent response of plasmonic antennas at femtosecond timescales. Exploiting the emerging properties of coupled antenna configurations, we use the calibrated antennas to engineer two sought-after applications of ultrafast plasmonics: a subwavelength resolution phase shaper, and an ultrafast hotspot switch. Moreover, we demonstrate that mixing localized resonances of lossy plasmonic particles is the mechanism behind nanoscale coherent control. This simple, reproducible and scalable approach promises to transform ultrafast plasmonics into a straightforward tool for use in fields as diverse as room temperature quantum optics, nanoscale solid state physics and quantum biology.
The encoding of quantum information in photonic time-bin qubits is apt for long distance quantum communication schemes. In practice, due to technical constraints such as detector response time, or the speed with which co-polarized time-bins can be sw
itched, other encodings, e.g. polarization, are often preferred for operations like state detection. Here, we present the conversion of qubits between polarization and time-bin encodings using a method that is based on an ultrafast optical Kerr shutter and attain efficiencies of 97% and an average fidelity of 0.827+/-0.003 with shutter speeds near 1 ps. Our demonstration delineates an essential requirement for the development of hybrid and high-rate optical quantum networks.
We report a measurement on the temporal response of a plasmonic antenna at the femtosecond time scale. The antenna consists of a square array of nanometer-size gold rods. We find that the far-field dispersion of light reflected from the plasmonic ant
enna is less than that of a 1.2 mm thick glass slide. Assuming a simple oscillating dipole model this implies that the near-field of the antenna may be used as an electron switch that responds faster than 20 fs. Alternatively, ultrafast electron diffraction may be used to investigate the near-field dynamics of the plasmonic antenna.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
