Browsing by Author "Gwo, Shangir"

Now showing 1 - 4 of 4

Efficient single photon sources based on nanodiamonds on a plasmonic platform
(2014)
Chen, Yen-Chun
;
Tsai, Cheng-Yen
;
Wang, Chun-Yuan
;
Gwo, Shangir
;
Wen-HaoChang
We report on an efficient room-temperature source of single photons based on single nitrogen-vacancy centers in nanodiamonds (NDs) placing on a large-area plasmonic platform formed by crystalline gold flakes covered with a thin dielectric layer. Due to the strongly confined plasmonic fields in the thin dielectric layer, the NDs show a large enhancement in the fluorescence intensity without significant degradation in single photon purity. According to the deduced fluorescence lifetime from g((2)) measurements, the Purcell factor is estimated to be similar to 1.4. The plasmonic platform is very ideal for large-area fluorescence enhancement without the needs of sophisticated nanopositioning schemes for locating NDs at local hot spots in conventional plasmonic nanostructures.
Low Resistivity Metal Silicide Nanowires with Extraordinarily High Aspect Ratio for Future Nanoelectronic Devices
(2011-11-01)
Chen, Sheng-Yu
;
Yeh, Ping-Hung
;
Wu, Wen-Wei
;
Chen, Uei-Shin
;
Chueh, Yu-Lun
One crucial challenge for the integrated circuit devices to go beyond the current technology has been to find the appropriate contact and interconnect materials. NISI has been commonly used in the 45 nm devices mainly because it possesses the lowest resistivity among all metal silicides. However, for devices of even smaller dimension, its stability at processing temperature is in doubt. In this paper, we show the growth of high-quality nanowires of NiSi(2), which is a thermodynamically stable phase and possesses low resistivity suitable for future generation electronics devices. The origin of low resistivity for the nanowires has been clarified to be due to its defect-free single-crystalline structure instead of surface and size effects.
Low-Threshold Plasmonic Lasers on a Single-Crystalline Epitaxial Silver Platform at Telecom Wavelength
(2017-06-01)
Lee, Chien-Ju
;
Yeh, Han
;
Cheng, Fei
;
Su, Ping-Hsiang
;
Her, Tsing-Hua
We report on the first demonstration of metal insulator semiconductor-type plasmonic lasers at the telecom wavelength (similar to 1.3 mu m) using top-down fabricated semiconductor waveguides on single-crystalline metallic platforms formed using epitaxially grown Ag films. The critical role of the Ag film thickness in sustaining. plasmonic lasing at the telecom wavelength is investigated systematically. Low-threshold (0.2 MW/cm(2)) and continuous-wave operation of plasmonic lasing at cryogenic temperatures can be achieved on a 150 nm Ag platform with minimum radiation leakage into the substrate. Plasmonic lasing occurs preferentially through higher-order surface-plasmon-polariton modes, which exhibit a higher mode confinement factor, lower propagation loss, and better field gain coupling. We observed plasmonic lasing up to 200 K under pulsed excitations. The plasmonic lasers on large-area epitaxial Ag films open up a scalable platform for on-chip integrations of plasmonics and optoelectronics at the telecom wavelength.
Plasmonic whispering-gallery modes in a semiconductor-insulator-metal hybrid structure
(2015)
Lee, Chien-Ju
;
Yeh, Han
;
Chen, Yen-Chun
;
Wang, Chun-Yuan
;
Gwo, Shangir
We demonstrate a plasmonic cavity based on a hybrid semiconductor-insulator-metal structure, which can support plasmonic whispering-gallery modes (WGMs) in the insulator layer. The hybrid structure consists of a semiconductor microdisk with embedded gain medium on top of a single-crystalline gold flake with a nanometer-thick dielectric gap in between. By optimizing the dielectric gap thickness, it is possible to form coupled modes consisting of both photonic WGM in the microdisk and plasmonic WGM in the dielectric gap, by which a high field-gain overlap and an efficient cavity feedback can be achieved for investigating strong light-matter interactions and laser applications.