ABSTRACT
Chip-scale optical devices operated at wavelengths shorter than communication wavelengths, such as LiDAR for autonomous driving, bio-sensing, and quantum computation, have been developed in the field of photonics. In data processing involving optical devices, modulators are indispensable for the conversion of electronic signals into optical signals. However, existing modulators have a high half-wave voltage-length product (VπL) which is not sufficient at wavelengths below 1000 nm. Herein, we developed a significantly efficient optical modulator which has low VπL of 0.52 V·cm at λ = 640 nm using an electro-optic (EO) polymer, with a high glass transition temperature (Tg = 164 °C) and low optical absorption loss (2.6 dB/cm) at λ = 640 nm. This modulator is not only more efficient than any EO-polymer modulator reported thus far, but can also enable ultra-high-speed data communication and light manipulation for optical platforms operating in the ranges of visible and below 1000 nm infrared.
ABSTRACT
We fabricated a hybrid plasmonic device using self-imaging effect between guided light and surface plasmon polaritons in the hybrid plasmonic waveguide. The hybrid plasmonic device was fabricated by evaporating gold on the part of the silicon waveguide. Self-imaging was generated at the gold-covered section in the waveguide. Self-imaging of guided light and surface plasmon polaritons in hybrid plasmonic waveguides affect the output intensity of the hybrid plasmonic waveguide. The length of the hybrid plasmonic waveguide changes self-imaging conditions. We confirmed that the output intensity was affected by the length of the hybrid plasmonic waveguide. These findings contribute to the development of hybrid plasmonic devices and potentially improve integration density of hybrid photonic integrated circuits.
ABSTRACT
We proposed and designed a compact unbalanced Mach-Zehnder interferometer (MZI) based on metal/insulator/metal (MIM) plasmonic waveguides for ultrafast optical signal processing. The MZI was fabricated by a lithography technique and we provide, for the first time experimental evaluation of the transmission performance of the MZI using MIM PWGs. The experimental results were in good agreement with the numerical simulations. The proposed structure could be considered as a key device for on-chip optical integrated circuits.
ABSTRACT
PURPOSE: Lidocaine has a biphasic action on smooth muscle of peripheral blood vessels, with vasoconstriction at low concentrations and vasodilation at higher concentrations. Many in vivo studies have demonstrated the effects of lidocaine on aortic or coronary arteries in several animals, but there are few reports about the effect on peripheral vessels. This study was designed to investigate the direct effects of lidocaine on peripheral vessels, namely swine lingual and pulmonary arterial rings. METHODS: Swine lingual artery and pulmonary artery segments, about 2-3 mm in diameter, were cut into 3-mm-long rings, and the lumen surface was gently rubbed to remove the endothelium. Isometric tension was measured using a displacement transducer and recorded. After a stable constriction was developed with 5 µM noradrenaline, 5 µM noradrenaline containing lidocaine (0.5, 1.0, 10, 20, 50 or 100 µg/ml) was perfused for 5 min, and then all drug perfusion was stopped. The strength of any isometric tension during an experiment was normalized to the strength of the isometric tension immediately before lidocaine perfusion, and expressed as a percentage. RESULTS: Lidocaine elicited a concentration-dependent biphasic response of lingual and pulmonary arterial rings. The lidocaine concentration at 1 µg/ml caused mild contraction. Dilation occurred at 10 µg/ml and increased with increasing dose. CONCLUSIONS: Lidocaine-induced vasoconstriction of swine lingual and pulmonary smooth muscle may occur at low concentration when lidocaine is infiltrated into the oral submucosa or administered intravenously for the treatment of ventricular arrhythmia.
