Browsing by Author "Yang, Yu-Lin"

Now showing 1 - 11 of 11

Demonstration of multilayer titanium photonic crystals with 100-nm feature sizes
(2008-01-01)
Wu, Shich-Chuan
;
Lin, Chuan-Ding
;
Yang, Yu-Lin
;
Chen, Jing-Shian
;
Huang, Yang-Tung
Multilayer titanium photonic crystals are fabricated with the mature integrated circuit (IC) technology, which is similar to the Damascene interconnect process. The photonic crystals that we created have the face-centered-tetragonal lattice symmetry. In each layer, the feature size, height and the spacing of the titanium rods is 100 nm, 200 nm and 300 nm, respectively. To our knowledge, this is at the first time that the three-dimensional titanium photonic crystals are realized successfully with 100-nm line width. The reflectance spectra of three- and four-layer titanium photonic crystals are measured with the Fourier-transform infrared spectroscopy and simulated with the three-dimensional finite different time domain method. Through both the experimental observation and the calculation verification, the characterization of the photonic band gap is demonstrated at near-infrared wavelengths and the optical behavior of titanium photonic crystals is discussed for incident light waves of s- and p-polarization. Moreover, the absorption spectra are derived from the reflectance and transmittance spectra due to the law of conservation of energy. It is found that absorption near the photonic band edge is modified and enhanced in a narrow bandwidth because of the well-known recycling-energy mechanism. The large band gap can suppress black body radiation in the mid-infrared range and recycle energy into the near infrared. According to Kirchoff's law, the absorptance of a body equals its emissivity. Thus, the multilayer titanium photonic crystals would be applied as an efficient near-infrared light source with a narrow bandwidth, and produced on a mass scale with the standard IC technology.
Design of a multimode interference-based 1x2 wavelength-division-demultiplexer on an air-hole photonic crystal
(2007)
Lu, Ming-Feng
;
Hong, Chung-Yu
;
Yang, Yu-Lin
;
Huang, Yang-Tung
;
電子工程學系及電子研究所
In this study, the multimode interference (MMI) phenomenon and the self-imaging principle in two-dimensional (2D) photonic crystal (PC) waveguides are investigated. By using the finite-difference time-domain (FDTD) computation, the self-imaging phenomenon and the imaging positions along the propagation path on a PC multimode waveguide are in good agreement with those derived from the modal propagation analysis (MPA). This mean that the analytic methods for MMI in conventional multimode waveguides still work in 2D PC waveguides. Moreover, a MMI-based 1-to-2 wavelength-division-demultiplexer is designed on an air-hole photonic crystal structure, which can be applied in a coarse wavelength division multiplexing. (CWDM) system. The performance simulated by the FDTD method shows that the insertion loss and the contrast are (0.33 dB, 15.45 dB) and (0.33 dB, 12.9 dB) for the wavelength 1480 nm and 1625 nm, respectively.
Design, fabrication, and characterization of Si-based ARROW photonic crystal bend waveguides and power splitters
(2012-08-20)
Chen, Jian-Hua
;
Huang, Yang-Tung
;
Yang, Yu-Lin
;
Lu, Ming-Feng
;
Shieh, Jia-Min
Silicon-based (Si-based) photonic crystal waveguide based on antiresonant reflecting optical waveguide (ARROW PCW) structures consisting of 60 degrees bends and Y-branch power splitters were designed and first efficiently fabricated and characterized. The ARROW structure has a relatively large core size suitable for efficient coupling with a single-mode fiber. Simple capsule-shaped topography defects at 60 degrees photonic crystal (PC) bend corners and Y-branch PC power splitters were used for increasing the broadband light transmission. In the preliminary measurements, the propagation losses of the ARROW PC straight waveguides lower than 2 dB/mm with a long length of 1500 mu m were achieved. The average bend loss of 60 degrees PC bend waveguides was lower than 3 dB/bend. For the Y-branch PC power splitters, the average power imbalance was lower than 0.6 dB. The results show that our fabricated Si-based ARROW PCWs with 60 degrees bends and Y-branch structures can provide good light transmission and power-splitting ability. (c) 2012 Optical Society of America
Design, Fabrication, and Characterization of Si-Based ARROW-B Photonic Crystal Sharp-Bend Waveguides and Power Splitters
(2012-07-15)
Chen, Jian-Hua
;
Huang, Yang-Tung
;
Yang, Yu-Lin
;
Lu, Ming-Feng
;
生物科技學系
Si-based type-B antiresonant reflecting optical waveguide (ARROW-B) photonic crystal waveguides (PCWs) with 60 degrees bend, 120 degrees bend, and Y-branch power splitter were first successfully fabricated and characterized. A simple capsule-shaped defect was designed to modulate the 60 degrees and 120 degrees photonic crystal (PC) bend corners and Y-branch PC power splitters. In the preliminary experiments, the average bend losses of 60 degrees and 120 degrees PC bend waveguides for both polarizations were lower than 1.5 and 4.2 dB/bend, respectively. For the Y-branch PC power splitters, power imbalances for both polarizations were all lower than 0.7 dB. It shows that the fabricated Si-based ARROW-B PCWs can provide good light sharp-bend ability and power-split ability.
Effect of Crystallinity on the Optical Reflectance of Cylindrical Colloidal Crystals
(2011)
Lai, Chun-Han
;
Yang, Yu-Lin
;
Chen, Li-Yin
;
Huang, Yi-Jui
;
Chen, Jing-Yu
We fabricate cylindrical colloidal crystals (CCCs) via electrophoretic depositions of polystyrene microspheres on a carbon fiber in a concentric arrangement. Images from optical and scanning electron microscope indicate that the CCCs of 460 nm microspheres reveal a semicrystalline structure in close-packed lattice, while the CCCs of 660 exhibit an amorphous arrangement. In optical reflectance spectra, both CCCs demonstrate a dispersive photonic bandgap as compared to that from planar counterparts. The curved contour for the CCCs renders incident light interacting with reflecting planes at slightly different angles, leading to a notable reduction in the reflectance intensity and minor relocation of photonic bandgap contingent on their crystallinity. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3536511] All rights reserved.
Fabrication and characterization of three-dimensional all metallic photonic crystals for near infrared applications
(2009-01-26)
Yang, Yu-Lin
;
Hou, Fu-Ju
;
Wu, Shich-Chuan
;
Huang, Wen-Hsien
;
Lai, Ming-Chih
Three-dimensional all metallic photonic crystals with a feature size of 0.20 mu m were fabricated using electron-beam lithography with the photoresist of hydrogen silesquioxane. This process method has high compatibility with the fabrication of damascene copper interconnections and also simplifies the whole process flow. The dependence of the complete photonic band gaps on polarization was experimentally observed and compared with the simulation results. The band edge for the four-layer lattice was found at a wavelength of around 0.80 mu m in normal incidence.
Fabrication and properties of Cu-Ni mixed-metal periodical array for midinfrared filtering and hydrophobic application
(2008-09-01)
Huang, Wen-Hsien
;
Yang, Yu-Lin
;
Wu, Shich-Chuan
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Cu was grown successfully on Ni film as a conductive layer that demonstrated a stronger Cu (111) preferred crystallographic orientation. Furthermore, we studied the scale effect of various periods of patterned Ni lines separated by variable widths of SiO2. When Cu was electroplated onto this patterned Ni, it preferentially deposited on the Ni edges adjacent to the SiO2 stripes, resulting in a Cu-Ni-Cu-SiO2, Cu-SiO2-Cu, or Cu-Cu structure, depending on the dimensions of the starting Ni pattern and the deposition time. There are two reflective dips at 2.2 and 8 mu m wavelengths using Fourier transform infrared spectroscopy, which revealed a trend of narrower bandwidth in reflective spectra and a redshift effect with increasing deposition time. Interestingly, a hydrophobic surface was also observed due to its particular surface-roughness structures that could be controlled by the deposition time and altered the contact angle from 72 degrees to 110 degrees without coating any extra low free-energy materials. (C) 2008 American Vacuum Society.
Layer-by-Layer Copper Photonic Crystals for Near Infrared Spectral Region
(2010)
Wu, Shich-Chuan
;
Yang, Yu-Lin
;
Huang, Wen-Hsien
;
Huang, Yang-Tung
;
電子工程學系及電子研究所
We selected copper as the material to form the 3D structures with feature sizes of 0.4 mu m to study its desirable optical properties at near infrared wavelengths from using the high compatible process of damascene copper interconnections technique. The reflectance and transmittance spectra of the 3D copper photonic crystals were measured with the Fourier-transform infrared (FTIR) spectroscopy and simulated with the 3D FDTD method. Through both the experimental observation and the calculation verification, the characterization of the PBG is right at near infrared wavelengths. It is worth noted that some interesting behavior were observed in the spectra and transmitting ratio under different polarization incident conditions.
Numerical Study of Transmission Improvement in a Photonic Crystal Waveguide Bend by Mode-Matching Technique
(2008-11-01)
Lu, Ming-Feng
;
Yang, Yu-Lin
;
Huang, Yang-Tung
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An approach to improve the transmission efficiency of photonic crystal (PC) waveguide bends through maximization of the overlap integral of fields between the straight waveguide and the waveguide bend is presented. By shifting the lattice points around the bend corner, the bound state in the waveguide bend and the guided mode in the straight waveguide are matching, and the transmission of a PC waveguide bend can be significantly improved. The transmission of a 120 degrees PC waveguide bend with mode matching is dramatically improved from 5.7% to 87.5%. The bound state in a PC waveguide bend is similar to a cavity mode; therefore, the PC waveguide bend performs a narrowband transmission. Frequency shift of the spectra for a PC waveguide bend due to this lattice shifting can also be observed.
Photonic Crystal Slab Waveguides Based on Antiresonant Reflecting Optical Waveguide Structures
(2009-07-15)
Yang, Yu-Lin
;
Hsu, Shih-Hsin
;
Lu, Ming-Feng
;
Huang, Yang-Tung
;
生物科技學系
A novel two-dimensional photonic crystal slab waveguide based on an antiresonant reflecting optical waveguide (ARROW) structure is proposed and designed. Lightwaves propagating in this waveguide are confined by antiresonance reflection vertically and the photonic band gap laterally. In order to obtain the characteristics of the ARROW-based photonic crystal waveguides, the three-dimensional finite-difference time-domain simulations are performed. With a lateral adiabatic taper, a coupling efficiency of 80.3% from a single-mode fiber to the ARROW-based photonic crystal waveguide of a single-line defect is obtained. In addition, propagation losses less than 10 dB/mm and bend losses of 0.23 and 0.39 dB/bend for the designed 60 degrees and 120 degrees bends are achieved at an operating wavelength of 1.55 mu m.
Thermal emission at near-infrared wavelengths from three-dimensional copper photonic crystals
(2011-08-15)
Wu, Shich-Chuan
;
Yang, Yu-Lin
;
Huang, Wen-Hsien
;
Huang, Yang-Tung
;
電子工程學系及電子研究所
A three-dimensional copper photonic crystal was fabricated with the high compatibility process, damascene copper interconnections technique. The reflectance and transmittance spectra of this structure were measured with the Fourier-transform infrared spectroscopy and simulated with the 3 D finite-difference time-domain method. From the experiment data, it is shown that this structure exhibits a large photonic bandgap from mid-infrared regime to lambda = 1.95 mu m. At a heating temperature of 420 degrees C, it is observed that thermal emission is enhanced near the bandedge lambda = 1.71 mu m and suppressed in the bandgap region. This is attributed to the enhancement of photonic density of states near the bandedge. (C) 2011 American Institute of Physics. [doi:10.1063/1.3625263]