Browsing by Author "Lin, Pin-Tso"

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A Novel Hybrid Plasmonic Rod-dimer/Ring Nanostructure for Sensing and Trapping
(2014)
Lin, Jia-Yu
;
Tsai, Chia-Yang
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Lin, Pin-Tso
;
Hsu, Tse-En
;
Lee, Po-Tsung
We propose and investigate a novel hybrid plasmonic rod-dimer/ring (RDR) nanostructure with significantly enhanced near-field at the gap region for its potential on sensing and trapping applications.
All-optical controllable trapping and transport of subwavelength particles on a tapered photonic crystal waveguide
(2011-02-01)
Lin, Pin-Tso
;
Lee, Po-Tsung
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光電工程學系
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Department of Photonics
We propose that a tapered photonic crystal waveguide design can unify optical trapping and transport functionalities to advance the controllability of optical manipulation. Subwavelength particles can be trapped by a resonance-enhanced field and transported to a specified position along the waveguide on demand by varying the input wavelength. A simulated transport ability as high as 148 (transport distance/wavelength variation) is obtained by the waveguide with 0.1 degrees tilted angle. Stable trapping of a 50 nm polystyrene particle can be achieved with input power of 7 mW. We anticipate that this design would be beneficial for future life science research and optomechanical applications. (C) 2011 Optical Society of America
Efficient transportation of nano-sized particles along slotted photonic crystal waveguide
(2012-01-30)
Lin, Pin-Tso
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Lee, Po-Tsung
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光電工程學系
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Department of Photonics
We design a slotted photonic crystal waveguide (S-PhCW) and numerically propose that it can efficiently transport polystyrene particle with diameter as small as 50 nm in a 100 nm slot. Excellent optical confinement and slow light effect provided by the photonic crystal structure greatly enhance the optical force exerted on the particle. The S-PhCW can thus transport the particle with optical propulsion force as strong as 5.3 pN/W, which is over 10 times stronger than that generated by the slotted strip waveguide (S-SW). In addition, the vertical optical attraction force induced in the S-PhCW is over 2 times stronger than that of the S-SW. Therefore, the S-PhCW transports particles not only efficiently but also stably. We anticipate this waveguide structure will be beneficial for the future lab-on-chip development (C)2012 Optical Society of America
Nanophotonic structures for highly efficient on-chip optical manipulation
(2018-01-01)
Lee, Po-Tsung
;
Lu, Tsan-Wen
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Lin, Pin-Tso
;
Lin, Chia-Yu
;
Tsai, Chia-Yang
In this report, we introduce our proposed nanophotonic structures for highly efficient optical manipulation, including utilizing photonic crystal waveguides, nanocavities, and metallic structures with localized surface plasmon resonances. Owing to their waveguide-accessible configurations and highly concentrated optical modes with large field gradients beyond the diffraction limit, highly efficient optical trapping can be realized in sub-wavelength scale.
One-dimensional photonic crystal fishbone hybrid nanocavity with nanoposts
(2014-05-12)
Lu, Tsan-Wen
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Lin, Pin-Tso
;
Lee, Po-Tsung
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光電工程學系
;
Department of Photonics
We propose and investigate a one-dimensional photonic crystal (PhC) fishbone (FB) hybrid nanocavity lying on silver substrate with a horizontal air slot. With very few PhC periods, the confined transverse-magnetic, TM10 hybrid mode concentrated within the air slot shows high quality factor over effective mode volume ratio larger than 10(5) lambda(-3). Most importantly, this FB hybrid nanocavity allows formation of low-index nanoposts within the air slot without significantly affecting the mode properties. These nanoposts guarantee the structural stabilities under different environmental perturbations. Furthermore, capabilities of our proposed design in serving as optical sensors and tweezers for bio-sized nanoparticles are also investigated. (C) 2014 AIP Publishing LLC.
One-dimensional photonic crystal nanobeam lasers on a flexible substrate
(2011-08-15)
Lu, Tsan-Wen
;
Chiu, Li-Hsun
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Lin, Pin-Tso
;
Lee, Po-Tsung
;
光電工程學系
We demonstrate a one-dimensional (1D) photonic crystal (PhC) nanocavity laser composed of hybrid PhC mirrors on a suspended nanobeam (NB) with very small device footprint of 8.5 x 0.57 mu m(2). The 0th-order mode lasing action with low threshold of 280 mu W is observed. Via the optical glue stamping process, the devices are directly transferred onto a flexible polypropylene substrate. Single mode lasing action with effective threshold of 17 mu W is achieved. The robust lasing properties of the device with different bending radii R from infinity to 2.5 mm are obtained. Via finite-element method, we also theoretically address that the lasing wavelength is almost invariant when R> 1.0 mm. This flexible 1D PhC NB laser will be a good candidate for efficient nanolaser in future flexible photonic integrated circuits with ultrahigh component density. (C) 2011 American Institute of Physics. [doi:10.1063/1.3626592]
Optical Properties of Plasmonic Mirror-Image Nanoepsilon
(2016-07-12)
Lin, Jia-Yu
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Tsai, Chia-Yang
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Lin, Pin-Tso
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Hsu, Tse-En
;
Hsiao, Chi-Fan
We propose a novel mirror-image nanoepsilon (MINE) structure to achieve highly localized and enhanced near field at its gap and systematically investigate its plasmonic behaviors. The MINE can be regarded as a combination of two fundamental plasmonic nanostructures: a nanorod dimer and nanoring. By adapting a nanoring surrounding a nanorod dimer structure, the nanorod is regarded as a bridge pulling the charges from the nanoring to the nanorod, which induces stronger plasmon coupling in the gap to boost local near-field enhancement. Two resonance peaks are identified as the symmetric and anti-symmetric modes according to the symmetries of the charge distributions on the ring and rod dimer in the MINE. The symmetric mode in the MINE structure is preferred because its charge distribution leads to stronger near-field enhancement with a concentrated distribution around the gap. In addition, we investigate the influence of geometry on the optical properties of MINE structures by performing experiments and simulations. These results indicate that the MINE possesses highly tunable optical properties and that significant near-field enhancement at the gap region and rod tips can be realized by the gap and lightning-rod effects. The results improve understanding of such complex systems, and it is expected to guide and facilitate the design of optimum MINE structures for various plasmonic applications.
Optical sensing of square lattice photonic crystal point-shifted nanocavity for protein adsorption detection
(2010-05-24)
Lu, Tsan-Wen
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Lin, Pin-Tso
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Sio, Kuan-Un
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Lee, Po-Tsung
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光電工程學系
We propose a point-shifted D(0) nanocavity formed by locally modulating four central air holes in square lattice photonic crystal for optical sensing application. Three defect modes in this nanocavity, including monopole, whispering-gallery, and dipole modes, are identified in experiments. We also apply a chemical treatment on InGaAsP surface to form a 1-octadecanethiol linking monolayer, which enables the following protein adsorption. In experiments, the wavelength shifts of lasing modes in the D(0) nanocavity due to the protein adsorption are observed and agree with the simulation results. This can be a practical tool for label-free molecule detection in biomedical researches. (C) 2010 American Institute of Physics. [doi:10.1063/1.3436550]
Photonic crystal horizontally slotted nanobeam cavity for silicon-based nanolasers
(2012-02-15)
Lu, Tsan-Wen
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Lin, Pin-Tso
;
Lee, Po-Tsung
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光電工程學系
;
Department of Photonics
We theoretically propose and investigate a TM-polarized one-dimensional photonic crystal nanocavity with a horizontal SiO2 slot on a suspended silicon nanobeam via the three-dimensional finite-element method. The ultrahigh quality factor and ultrasmall effective mode volume of 1.5 x 10(7) and 0.176 half-wavelength cubic of the horizontally SiO2-slotted nanocavity show strong possibilities for realizing an erbium-doped SiO2 nanolaser. This horizontal SiO2 slot structure can be precisely formed via the sputtering process and further transformed into an air slot via selective wet etching for optical index and biomolecule sensing. (C) 2012 Optical Society of America
Photonic crystal waveguide cavity with waist design for efficient trapping and detection of nanoparticles
(2014-03-24)
Lin, Pin-Tso
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Lu, Tsan-Wen
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Lee, Po-Tsung
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光電工程學系
;
Department of Photonics
For manipulating nanometric particles, we propose a photonic crystal waveguide cavity design with a waist structure to enhance resonance characteristic of the cavity. For trapping a polystyrene particle of 50 nm radius on the lateral side of the waist, the optical force can reach 2308 pN/W with 24.7% signal transmission. Threshold power of only 0.32 mW is required for stable trapping. The total length of the device is relatively short with only ten photonic crystal periods, and the trapping can occur precisely and only at the waist. The designed cavity can also provide particle detection and surrounding medium sensing using the transmission spectrum with narrow linewidth. The simulated figure of merit of 110.6 is relatively high compared with those obtained from most plasmonic structures for sensing application. We anticipate this design with features of compact, efficient, and versatile in functionality will be beneficial for developing lab-on-chip in the future. (C)2014 Optical Society of America
Plasmonic Coupling in Gold Nanoring Dimers: Observation of Coupled Bonding Mode
(2012-03-01)
Tsai, Chia-Yang
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Lin, Jyun-Wei
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Wu, Che-Yao
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Lin, Pin-Tso
;
Lu, Tsan-Wen
We investigate the optical properties of gold nanoring (NR) dimers in both simulation and experiment. The resonance peak wavelength of gold NR dimers is strongly dependent on the polarization direction and gap distance. As the gold NR particles approach each other, exponential red shift and slight blue shift of coupled bonding (CB) mode in gold NR dimers for longitudinal and transverse polarizations are obtained. In finite element method analysis, a very strong surface plasmon coupling in the gap region of gold NR diners is observed, whose field intensity at the gap distance of 10 nm is enhanced 23% compared to that for gold nanodisk (ND) dimers with the same diameter. In addition, plasmonic dimer system exhibits a great improvement in the sensing performance. Near field coupling in gold NR dimers causes exponential increase in sensitivity to refractive index of surrounding medium with decreasing the gap distance. Compared with coupled dipole mode in gold ND diners, CB mode in gold NR dimers shows higher index sensitivity. This better index sensing performance is resulted form the additional electric field in inside region of NR and the larger field enhancement in the gap region owing to the stronger coupling of collective dipole plasmon resonances for CB mode. These results pave the way to design plasmonic nanostructures for practical applications that require coupled metallic nanopartides with enhanced electric fields.
Square Lattice Photonic Crystal Point-Shifted D(0) Nanocavity with Lowest-Order Whispering-Gallery Mode
(2010)
Lu, Tsan-Wen
;
Lin, Pin-Tso
;
Sio, Kuan-Un
;
Lee, Po-Tsung
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光電工程學系
We propose a square photonic crystal point-shifted nanocavity, which sustains an ultra-small lowest-order whispering-gallery mode. Lasing actions with low threshold of 160 mu W and changed polarization due to a nearby nano-particle are observed. (C)2010 Optical Society of America
Square lattice photonic crystal point-shifted nanocavity with lowest-order whispering-gallery mode
(2010-02-01)
Lu, Tsan-Wen
;
Lin, Pin-Tso
;
Sio, Kuan-Un
;
Lee, Po-Tsung
;
光電工程學系
We propose a point-shifted nanocavity based on square lattice photonic crystal, which sustains a lowest-order whispering-gallery (WG) mode. In simulation, the optimized WG mode (quality (Q) factor similar to 14,000) in point-shifted nanocavity can be with smaller mode volume (similar to 5.5(lambda/2n)(3)) but larger nano-post tolerance than those in single-defect cavity design. From well-fabricated device, single WG mode lasing with measured Q factor of 4,100 and low threshold of 160 mu W is obtained. Besides, we also observe the changed polarization of WG mode due to modal symmetry breaking caused by the presence of a nearby dielectric nano-particle, which would be useful in sensing molecule binding or attaching for bio-chemical applications. (C) 2010 Optical Society of America
TRAPPING NANO-SIZED PARTICLE BY WAVEGUIDE-COUPLED GOLD BOWTIE PLASMONIC TWEEZERS
(2014-01-01)
Lin, Pin-Tso
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Lin, I-Chang
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Chu, Heng-Yi
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Lu, Tsan-Wen
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Lee, Po-Tsung
Under the efficient and compact coupling from optical waveguide, the field highly enhanced and concentrated around gap of gold bowtie structure can trap nano-particle precisely with very strong optical forces compared with most nanophotonic tweezers.
Trapping particles using waveguide-coupled gold bowtie plasmonic tweezers (vol 14, pg 4647, 2014)
(2015-01-01)
Lin, Pin-Tso
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Chu, Heng-Yi
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Lu, Tsan-Wen
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Lee, Po-Tsung
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光電工程學系
Ultrahigh Q TM-Polarized Photonic Crystal Nano-Fishbone Nanocavity
(2013)
Lu, Tsan-Wen
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Lin, Pin-Tso
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Lee, Po-Tsung
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光電工程學系
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Department of Photonics
A novel photonic crystal nano-fishbone is proposed, which confines ultrahigh Q (similar to 1.6x10(7)) transverse magnetic mode with smaller mode volume, device size, surface area, and higher confinement factor than those in photonic crystal nanobeam.