Subwavelength probing of surface plasmons in magnetoplasmonic crystals

Abstract In this work, we report on near-field studying of propagating surface plasmons (SPs) in one-dimensional magnetoplasmonic crystals (MPCs) by aperture type scanning near-field optical microscopy (SNOM). Optical near-field around the aperture probe is used to drive SPs in the MPC locally. The SNOM signal represents the scattered intensity caused by the interaction of the SNOM probe near-field with the MPC. Scanning the MPC surface with polarization resolving of the scattered radiation shows decreasing of the intensity due to the SP excitation. The observed polarization dependence of the scattered SNOM signal is associated with the selective coupling of the near-field components of the SNOM probe with SPs. Finite-difference time-domain simulations reproduce the experimental SNOM signal. It is shown the excitation of SPs with symmetric (even parity) field distribution, which is forbidden for plane wave source at normal incidence.

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Three-Dimensional Finite-Difference Time-Domain Method Modeling of Nanowire Optical Probe

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.602-605.3359 ◽

2014 ◽

Vol 602-605 ◽

pp. 3359-3362

Author(s):

Chun Li Zhu ◽

Jing Li

Keyword(s):

Finite Difference ◽

Time Domain ◽

Finite Difference Time Domain ◽

Incident Light ◽

Near Field ◽

Three Dimensional ◽

Polarization Direction ◽

Near Field Imaging ◽

Difference Time ◽

Field Imaging

In this paper, output near fields of nanowires with different optical and structure configurations are calculated by using the three-dimensional finite-difference time-domain (3D FDTD) method. Then a nanowire with suitable near field distribution is chosen as the probe for scanning dielectric and metal nanogratings. Scanning results show that the resolution in near-field imaging of dielectric nanogratings can be as low as 80nm, and the imaging results are greatly influenced by the polarization direction of the incident light. Compared with dielectric nanogratings, metal nanogratings have significantly enhanced resolutions when the arrangement of gratings is perpendicular to the polarization direction of the incident light due to the enhancement effect of the localized surface plasmons (SPs). Results presented here could offer valuable references for practical applications in near-field imaging with nanowires as optical probes.

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Design of a Near-Field Probe for Optical Recording Using a 3-Dimensional Finite Difference Time Domain Method

Japanese Journal of Applied Physics ◽

10.1143/jjap.39.973 ◽

2000 ◽

Vol 39 (Part 1, No. 2B) ◽

pp. 973-975 ◽

Cited By ~ 10

Author(s):

Kusato Hirota ◽

Tom D. Milster ◽

Yan Zhang ◽

J. Kevin Erwin

Keyword(s):

Finite Difference ◽

Time Domain ◽

Finite Difference Time Domain ◽

Near Field ◽

Optical Recording ◽

Time Domain Method ◽

3 Dimensional ◽

Domain Method ◽

Difference Time

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From Time-Collocated to Leapfrog Fundamental Schemes for ADI and CDI FDTD Methods

Axioms ◽

10.3390/axioms11010023 ◽

2022 ◽

Vol 11 (1) ◽

pp. 23

Author(s):

Eng Leong Tan

Keyword(s):

Finite Difference ◽

Time Domain ◽

Finite Difference Time Domain ◽

Fdtd Method ◽

Unconditionally Stable ◽

Alternating Direction Implicit ◽

One Dimensional ◽

Alternating Direction ◽

Fdtd Methods ◽

Difference Time

The leapfrog schemes have been developed for unconditionally stable alternating-direction implicit (ADI) finite-difference time-domain (FDTD) method, and recently the complying-divergence implicit (CDI) FDTD method. In this paper, the formulations from time-collocated to leapfrog fundamental schemes are presented for ADI and CDI FDTD methods. For the ADI FDTD method, the time-collocated fundamental schemes are implemented using implicit E-E and E-H update procedures, which comprise simple and concise right-hand sides (RHS) in their update equations. From the fundamental implicit E-H scheme, the leapfrog ADI FDTD method is formulated in conventional form, whose RHS are simplified into the leapfrog fundamental scheme with reduced operations and improved efficiency. For the CDI FDTD method, the time-collocated fundamental scheme is presented based on locally one-dimensional (LOD) FDTD method with complying divergence. The formulations from time-collocated to leapfrog schemes are provided, which result in the leapfrog fundamental scheme for CDI FDTD method. Based on their fundamental forms, further insights are given into the relations of leapfrog fundamental schemes for ADI and CDI FDTD methods. The time-collocated fundamental schemes require considerably fewer operations than all conventional ADI, LOD and leapfrog ADI FDTD methods, while the leapfrog fundamental schemes for ADI and CDI FDTD methods constitute the most efficient implicit FDTD schemes to date.

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