Based on the theoretical model of Airy spot, a method is proposed for improving the imaging speed from confocal microscopy. The virtual Airy spot is designed for obtaining the pattern on CCD at detecting plane. Here the size of the spot is determined by the parameters of imaging system and intensity data from point detector, which can receive data quicker than CCD. The treatment can improve the speed of imaging comparing with CCD at receiving end. The virtual structured detection is also utilized for generating high-resolution image. Some numerical simulation results are provided for demonstrating the validity of the proposed method.
A novel nano-antenna for the generation and applications of THz wave is proposed based on the carbon nanotube. The
geometric structure and radiation properties of carbon nanotube (CNT) antenna at THz span have been investigated by
the finite integral numerical methods. The designed typical CNT antenna arrays (λ=3.0×104nm, L=0.485λ, R=2.712nm,
d=0.1λ) operate from 9.3 THz to 10.2 THz, and main resonant frequency is 9.7 THz. The simulated -10dB return loss
(S11) bandwidths is about 10% and the standing wave ratio is less than 1.5 at the center frequency of 9.7THz with the
total radiation efficiency in excess of 85%. The maximum gains for 5×5, 15×15, 25×25 CNT antenna array are 5.92dB,
8.19dB and 8.50dB in the center frequency, respectively. The details of THz antenna characteristics such as field
distribution, surface current profile, standing wave ratio, scattering coefficient and gain are presented and discussed. The
overall results could be suitable for the design of CNT antenna array generating THz wave.
This paper mainly presents a briefly review for recent progress in MEMS-based transmission lines for use in microwave and millimeterwave range. MEMS-based transmission lines including different transmission line structure such as membrane-supported microstrip line microstrip line, coplanar microshield transmission line, LIGA micromachined planar transmission line, micromachined waveguides and coplanar waveguide are discussed. MEMS-based transmission lines are characterized by low propagation loss, wide operation frequency band, low dispersion and high quality factor, in addition, the fabrication is compatible with traditional processing of integrated circuits (IC’s). The emergence of MEMS-based transmission lines provided a solution for miniaturizing microwave system and monolithic microwave integrated circuits.
Microelectromechanical system (MEMS) represents an exciting new technology derived from the same fabricating processes used to make integrated circuits. The trends of growing importance of the wireless communications market is toward the system with minimal size, cost and power consumption. For the purpose of MEMS R&D used for wireless communications, a history and present situation of MEMS device development are reviewed in this paper, and an overview of MEMS research topics on RF communication applications and the state of the art technologies are also presented here.
A Nd:GGG(Ca,Mg,Zr) and a Nd:YAG laser were compared when end-pumped by a continuous-wave laser diode. With a 30-mW single-stripe laser diode, 2.4 mW and 4.6 mW of output power were obtained for the Nd:GGG(Ca,Mg,Zr) and the Nd:YAG laser, respectively. With a 1-watt laser-diode array, the output power increased to 223 mW for the Nd:GGG(Ca,Mg,Zr) and 297 mW for the Nd:YAG laser. The Nd:GGG(Ca,Mg,Zr) was also pumped by a 19-watt quasi-continuous-wave laser-diode bar. Side and end pumping were compared. With the appropriate optics the end-pumped geometry was more efficient and gave more power, 47% slope efficiency with 4.3 watts of output power, compared to side-pumped geometry, 16% slope efficiency with 2.6 watts.
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