Single-longitudinal-mode operation of a grating-based fiber-ring laser using self-injection feedback

A fiber Bragg grating- (FBG-) based fiber-ring laser that utilizes the transmitted light of the FBG as self-injection feedback for single-longitudinal-mode (SLM) oscillation is proposed and demonstrated. This laser is simply constructed by means of feeding back the transmitted light of the FBG and is coupled into the main ring cavity through an optical coupler. The self-injection feedback is the key to ensuring SLM laser oscillation. The SLM operation principle is discussed in detail, and a SLM laser with output power of 6.6 dBm, an optical signal-to-noise ratio of 57 dB at 1549.19 nm, and a short-term linewidth of 3.5 kHz is reported.     

相移测量技术中相移器研究

本文介绍一种用于相移测量技术的相移器。该相移器由计算机通过Ｄ／Ａ接口板自动控制输出电压幅度，其电路采用闭环控制，位移由压电晶体产生，具有很高的电压稳定度（０１％）和较小的相移误差（小于３°）。描述相移器的结构、驱动源工作原理及相移器标定方法     

Three-dimensional vertical ZnO transistors with suspended top electrodes fabricated by focused ion beam technology

Three-dimensional(3D)vertical architecture transistors represent an important technological pursuit,which have distinct advantages in device integration density,operation speed,and power consumption.However,the fabrication processes of such 3D devices are complex,especially in the interconnection of electrodes.In this paper,we present a novel method which combines suspended electrodes and focused ion beam(FIB)technology to greatly simplify the electrodes interconnection in 3D devices.Based on this method,we fabricate 3D vertical core-double shell structure transistors with ZnO channel and Al₂O₃ gate-oxide both grown by atomic layer deposition.Suspended top electrodes of vertical architecture could be directly connected to planar electrodes by FIB deposited Pt nanowires,which avoid cumbersome steps in the traditional 3D structure fabrication technology.Both single pillar and arrays devices show well behaved transfer characteristics with an Ion/Ioff current ratio greater than 106 and a low threshold voltage around 0 V.The ON-current of the 2×2 pillars vertical channel transistor was 1.2μA at the gate voltage of 3 V and drain voltage of 2 V,which can be also improved by increasing the number of pillars.Our method for fabricating vertical architecture transistors can be promising for device applications with high integration density and low power consumption.     

超导磁共振仪器设备国产化现状及挑战

磁共振在化学分析和医学影像等领域发挥着不可或缺的作用,而磁共振仪器设备是开展磁共振研究的必要前提.长期以来,国外仪器厂商在我国磁共振仪器市场居于垄断地位.近年来,随着我国在磁共振仪器研发和产业化方面不断取得进展,市场份额为外商垄断的局面已大为改观.本文调研综述了我国磁共振仪器设备研制的现状,以及面临的若干挑战.     

General one-loop formulas for $$Hrightarrow fbar{f}gamma $$ H → f f ¯ γ and its applications

The European Physical Journal C - Considering supergravity theory is a natural step in the development of gravity models. This paper follows the “algebraic“ path and constructs possible...     

Electronically Excited States in Model Complexes of Noble Metal Clusters with Carbon Nanodots

Russian Physics Journal - Theoretical calculations of excited states in the complexes of gold and silver three-atom nanoclusters with carbon quantum nanodots are performed using the M062X...     

光电子成像研究AgOCH3-和Ag-(CH3OH)x (x=1, 2)

用光电子成像技术和从头算法研究Ag^-(CH₃OH)_x (x=1, 2)和AgOCH₃^-. 从AgOCH₃^-振动分辨的光电子谱得 到AgOCH₃^-的绝热和垂直电离能分别为1.29(2)和1.34(2) eV. Ag^-(CH₃OH)_{1,2相似文献}   

Method for suppressing the mirror image in Fourier-domain optical coherence tomography

A method, novel to our knowledge, for effective mirror image suppression in Fourier-domain optical coherence tomography based on a phase shift between neighboring A-mode scans is demonstrated. By realizing that the phase shifts of the real and mirror images are mutually reversed and assuming that the real image intensities of the two successive A-mode scans are the same, we can solve a set of two coupled equations to obtain the real image signals. The images based on the scanning of a high-resolution spectral-domain optical coherence tomography system are processed to show effective mirror image suppression results. Compared with a similar method of broad application, our approach has the advantages of shorter process time and higher flexibility in selecting the concerned image portions for processing.     

Highly sensitive miniature photonic crystal fiber refractive index sensor based on mode field excitation

A highly sensitive miniature photonic crystal fiber refractive index sensor based on field mode excitation is presented. The sensor is fabricated by melting one end of a photonic crystal fiber into a rounded tip and splicing and collapsing the other end with a single-mode fiber. The rounded tip is able to induce cladding mode excitation, which resulted in an additional phase delay. Linear response of 262.28 nm/refractive index unit in the refractive index range of 1.337 to 1.395 is obtained for the physical length of a 953 μm sensor. The sensor is also shown to be insensitive to environmental temperature.     

Cold nuclear matter effects on J/ψ yields as a function of rapidity and nuclear geometry in d+A collisions at sqrt[s(NN)]=200 GeV

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200 GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2相似文献