Browsing by Author "Lan, Tzu-Hsiang"

Now showing 1 - 8 of 8

Broad Detecting Range of Objective-Based Surface Plasmon Resonance Sensor via Multilayer Structure
(2011-09-01)
Lan, Tzu-Hsiang
;
Chung, Yi-Kuan
;
Tien, Chung-Hao
;
光電工程學系
;
顯示科技研究所
The demand of pursuing higher resolution drives the instrumental development of a surface plasmon resonance (SPR) sensor to shift from Kretchmann to objective-based configuration. However, its maximum sensing refractive index is restricted by the numerical aperture of an objective lens. Based on the mode conversion, we proposed a multilayer structure to extend the detecting range up to 11% (from 1.28 to 1.42) for a 1.45 objective lens via a transformed SPR mode. This technique not only overcomes intrinsic constraint but also reduces the cost. (C) 2011 The Japan Society of Applied Physics
Direct measurement of versatile surface plasmon polaritons excited by split polarization
(2011-02-21)
Lan, Tzu-Hsiang
;
Ho, Chen-Yeh
;
Tien, Chung-Hao
;
光電工程學系
;
顯示科技研究所
We report on the concept, generation, and observation of versatile excited surface plasmon polariton (SPP) patterns via focused split polarization. Unlike the conventional subwavelength features such as holes array, grating, or other protrusion to satisfy the phase matching condition for SPP excitation, we utilized a structured focus to form either counterpropagating interference or a multiple casting plasmonic pattern by means of the arrangement of split polarization and corresponding focus position. The characteristics of the near-field SPP image are in close agreement with the finite-difference time-domain calculation and confirm its feasibility associated with SPP excitations in many areas. (C) 2011 American Institute of Physics. [doi:10.1063/1.3552673]
Manipulation of the Steering and Shaping of SPPs via Spatially Inhomogeneous Polarized Illumination
(2010-10-25)
Lan, Tzu-Hsiang
;
Tien, Chung-Hao
;
光電工程學系
;
顯示科技研究所
;
Department of Photonics
In this paper, we demonstrated a far-field scheme for the manipulation of locally excited surface plasmon polaritons (SPPs). This scheme features steering and shaping capabilities, and relies on the focusing of a high numerical aperture, in conjunction with spatially inhomogeneous polarized (SIP) illumination. We were able to control the propagation and direction of SPPs, via the field distribution of polarization at the entrance pupil, without the need for an aperture, protrusion or any other near-field features. Depending on the axial position of the focus, the field distribution of excited SPPs revealed either counter-propagating interference or a multi-casting plasmonic source. The results of near-field imaging demonstrated the versatility of the SPPs, showing strong agreement with the predictions made during simulations. Due to the simplicity and versatility of the proposed method, we believe that it could have a significant impact the processes employed in the excitation of a variety of SPPs. (C) 2010 Optical Society of America
Plasmonic rainbow rings induced by white radial polarization
(2012-04-01)
Lan, Tzu-Hsiang
;
Chung, Yi-Kuan
;
Li, Jie-En
;
Tien, Chung-Hao
;
光電工程學系
This Letter presents a scheme to embed both angular/spectral surface plasmon resonance (SPR) in a unique far-field rainbow feature by tightly focusing (effective NA = 1.45) a polychromatic radially polarized beam on an Au(20 nm)/SiO2(500 nm)/Au(20 nm) sandwich structure. Without the need for angular or spectral scanning, the virtual spectral probe snapshots a wide operation range (n = 1-1.42; lambda = 400-700 nm) of SPR excitation in a locally nanosized region. Combined with the high-speed spectral analysis, a proof-of-concept scenario was given by monitoring the NaCl liquid concentration change in real time. The proposed scheme will certainly has a promising impact on the development of objective-based SPR sensor and biometric studies due to its rapidity and versatility. (C) 2012 Optical Society of America
Servo study of radially polarized beam in high numerical aperture optical data storage system
(2007-06-01)
Lan, Tzu-Hsiang
;
Tien, Chung-Hao
;
光電工程學系
;
顯示科技研究所
;
Department of Photonics
In this paper, we employed full vector diffraction treatment to study the dependence of the servo signals to the doughnutshaped focus radiation of radial polarization, which provides a smaller spot size than linear polarization, and the resistance to the primary aberrations in a numerical aperture (NA) = 1.0 optical data storage system. Compared with linear polarization, at strong focusing, a radially polarized beam leads to 14% asymmetry reduction in the linear range of the focus-error signal (FES) curve and to at least 56% variation reduction in crosstalk in a weakly aberrated system. These characteristics make radial polarization a potential candidate for next-generation high-density optical systems.
Study on focusing mechanism of radial polarization with immersion objective
(2008-07-01)
Lan, Tzu-Hsiang
;
Tien, Chung-Hao
;
光電工程學系
;
顯示科技研究所
;
Department of Photonics
In this study, we employ vectorial diffraction to examine the focusing mechanism of radially polarized beams using an immersion objective with linear and circular polarized illuminations. Radial polarization features a sharp focus in a highnumerical-aperture (NA) system. The longitudinal component governing spot formation depends on the bending of the polarization vector rather than the immersion circumstance. As the marginal angle of the objective exceeds 64.16 and 71.81 degrees, the depolarization effect of the radially polarized beam enables a smaller spot than the linear and circular polarizations, respectively.
Three-dimensional orientation-unlimited polarization encryption by a single optically configured vectorial beam
(2012-08-01)
Li, Xiangping
;
Lan, Tzu-Hsiang
;
Tien, Chung-Hao
;
Gu, Min
;
光電工程學系
The interplay between light polarization and matter is the basis of many fundamental physical processes and applications. However, the electromagnetic wave nature of light in free space sets a fundamental limit on the three-dimensional polarization orientation of a light beam. Although a high numerical aperture objective can be used to bend the wavefront of a radially polarized beam to generate the longitudinal polarization state in the focal volume, the arbitrary three-dimensional polarization orientation of a beam has not been achieved yet. Here we present a novel technique for generating arbitrary three-dimensional polarization orientation by a single optically configured vectorial beam. As a consequence, by applying this technique to gold nanorods, orientation-unlimited polarization encryption with ultra-security is demonstrated. These results represent a new landmark of the orientation-unlimited three-dimensional polarization control of the light-matter interaction.
Versatile Excitation of Localized Surface Plasmon Polaritons via Spatially Modulated Polarized Focus
(2010)
Lan, Tzu-Hsiang
;
He, Jan-Ya
;
Tien, Chung-Hao
;
光電工程學系
;
Department of Photonics
we proposed a method to generate a versatile localized surface plasmon with the capability of beam steering and shaping by using collinear Kretchmann configuration in conjunction with spatially inhomogeneous polarized beam.