http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hahn, Choloong,Song, Seok Ho,Oh, Cha Hwan,Berini, Pierre Optical Society of America 2015 Optics express Vol.23 No.15
<P>Single-mode distributed feedback laser structures and parity-time symmetry broken grating structures based on dielectric-loaded long-range surface plasmon polariton waveguides are proposed. The structures comprise a thin Ag stripe on an active polymer bottom cladding with an active polymer ridge. The active polymer assumed is PMMA doped with IR140 dye providing optical gain at near infrared wavelengths. Cutoff top ridge dimensions (thickness and width) are calculated using a finite element method and selected to guarantee single-mode operation of the laser. Several parameters such as the threshold number of periods and the lasing wavelength are determined using the transfer matrix method. A related structure based on two pairs of waveguides of two widths, which have the same imaginary part but different real part of effective index, arranged within one grating period, is proposed as an active grating operating at the threshold for parity-time symmetry breaking (i.e., operating at an exceptional point). Such 'exceptional point' gratings produce ideal reflectance asymmetry as demonstrated via transfer matrix computations.</P>
Nanofabrication of plasmonic structures on insulating substrates by resist-on-metal bilayer lift-off
Hahn, Choloong,Amyot-Bourgeois, Maude,Al-Shehab, Maryam,Northfield, Howard,Choi, Youngsun,Song, Seok Ho,Tait, R Niall,Berini, Pierre IOP 2019 Nanotechnology Vol.30 No.5
<P>In last few decades, micro- and nano-fabrication techniques based on photolithography and electron beam lithography have advanced greatly, mainly in the field of semiconductor fabrication. Such techniques are generally transferrable to the fabrication of plasmonic structures and metamaterials. However, plasmonic devices often require a transparent insulating substrate to be operational at visible or near-infrared wavelengths. Here we report a resist-on-metal bilayer lift-off technique enabling the fabrication of plasmonic structures on insulating substrates. The metal layer under the resist eliminates major difficulties in lithography, such as charging during electron beam exposure and uncontrolled diffuse optical scattering during photolithography. In addition, the resist-on-metal bilayer can be migrated to different substrates with minimal process alteration, because the material properties of the substrate, such as secondary electron emission or optical reflectance, become irrelevant due to the shielding provided by the metal layer. As demonstrations, we fabricate large-scale plasmonic waveguides and Bragg gratings, adiabatically-modulated plasmonic waveguide couplers, and plasmonic nanoantenna arrays using the resist-on-metal bilayer lift-off process. The process can also be used to define structures formed of other materials such as dielectrics.</P>
Time-asymmetric loop around an exceptional point over the full optical communications band
Yoon, Jae Woong,Choi, Youngsun,Hahn, Choloong,Kim, Gunpyo,Song, Seok Ho,Yang, Ki-Yeon,Lee, Jeong Yub,Kim, Yongsung,Lee, Chang Seung,Shin, Jai Kwang,Lee, Hong-Seok,Berini, Pierre Springer Science and Business Media LLC 2018 Nature Vol.562 No.7725