Asymmetrical Fabry-Perot cavity slot micro-ring resonator and its sensing characteristics

To achieve high quality factor and high-sensitivity refractive index sensor,a slot micro-ring resonator(MRR)based on asymmetric Fabry-Perot(FP)cavity was proposed.The structure consisted of a pair of elliptical holes to form an FP cavity and a microring resonator.The two different optical modes generated by the micro-ring resonator were destructively interfered to form a Fano line shape,which improved the system sensitivity while obtaining a higher quality factor and extinction ratio.The transmission principle of the structure was analyzed by the transfer matrix method.The transmission spectrum and mode field distribution of the proposed structure were simulated by the finite difference time domain(FDTD)method,and the key structural parameters affecting the Fano line shape in the device were optimized.The simulation results show that the quality factor of the device reached 22037.1,and the extinction ratio was 23.9 dB.By analyzing the refractive index sensing characteristics,the sensitivity of the structure was 354 nm·RIU−1,and the detection limit of the sensitivity was 2×10−4 RIU.Thus,the proposed compact asymmetric FP cavity slot micro-ring resonator has obvious advantages in sensing applications owing to its excellent performance.

Novel wavelet-homotopy Galerkin technique for analysis of lid-driven cavity flow and heat transfer with non-uniform boundary conditions

In this paper, a brand-new wavelet-homotopy Galerkin technique is developed to solve nonlinear ordinary or partial differential equations. Before this investigation,few studies have been done for handling nonlinear problems with non-uniform boundary conditions by means of the wavelet Galerkin technique, especially in the field of fluid mechanics and heat transfer. The lid-driven cavity flow and heat transfer are illustrated as a typical example to verify the validity and correctness of this proposed technique. The cavity is subject to the upper and lower walls’ motions in the same or opposite directions.The inclined angle of the square cavity is from 0 to π/2. Four different modes including uniform, linear, exponential, and sinusoidal heating are considered on the top and bottom walls, respectively, while the left and right walls are thermally isolated and stationary.A parametric analysis of heating distribution between upper and lower walls including the amplitude ratio from 0 to 1 and the phase deviation from 0 to 2π is conducted. The governing equations are non-dimensionalized in terms of the stream function-vorticity formulation and the temperature distribution function and then solved analytically subject to various boundary conditions. Comparisons with previous publications are given,showing high efficiency and great feasibility of the proposed technique.

Surface Plasmon Interference Lithography Assisted by a Fabry-Perot Cavity Composed of Subwavelength Metal Grating and Thin Metal Film

A surface plasmon interference lithography assisted by a Fabry-Perot （F-P） cavity composed of subwavelength metal gratings and a thin metal fihn is proposed to fabricate high-quality nanopatterns. The calculated results indicate that uniform straight interference fringes with high contrast and high electric-field intensity are formed in the resist under the F-P cavity. The analyses of spatial frequency spectra illuminate the physical mechanism of the formation for the interference fringes. The influence of the F-P cavity spacing is discussed in detail. Moreover, the error analyses reveal that all parameters except the metal grating period in this scheme can bear large tolerances for the device fabrication.

An Ultraviolet Fiber Fabry-Perot Cavity for Florescence Collection of Trapped Ions

We demonstrate a fiber Fabry-Pérot cavity in the ultraviolet range, which covers the florescence wavelength for the 2P to 2S transition of Yb and is designed in the bad cavity limit for florescence collection. Benefiting from both the small cavity mode volume and the large atom dipole, a cavity with moderate finesse and high transmission still supports a good cooperativity, which is made and tested in experiment. Based on the measured experimental parameters, simulation performed on the cavity and ion shows a Purcell factor better than 2.5 and a single-mode fiber collection efficiency over 10%. This technology can support ultra-bright single photon sources based on trapped ions and can provide the possibility to link remote atoms as a quantum network.

Improved Directivity of an OAM Antenna by a Fabry-Perot Cavity: An Experimental Study

The circular phased antenna array is commonly used for generating waves bearing Orbital Angular Momentum (OAM) in the radio frequency band, but it achieves a relatively low directivity. To overcome this drawback, we present here a method to improve the directivity of an OAM circular phased antenna array by embedding it inside a Fabry-Perot cavity. The Fabry-Perot cavity contains three main parts: a partially reflecting surface (PRS), an air cavity and a ground plane. Simulation data show that the directivity of this new OAM antenna achieves an improvement of 8.2 dB over the original array. A prototype is realized and characterized. The simulated and measured characteristics are in good agreement.

Measurement of Cavity Loss and Quasi-Fermi-Level Separation for Fabry-Pérot Semiconductor Lasers

A fitting process is used to measure the cavity loss and the quasi Fermi level separation for Fabry Pérot semiconductor lasers.From the amplified spontaneous emission (ASE) spectrum,the gain spectrum and single pass ASE obtained by the Cassidy method are applied in the fitting process.For a 1550nm quantum well InGaAsP ridge waveguide laser,the cavity loss of about ～24cm -1 is obtained.

Low insertion loss silicon-based spatial light modulator with high reflective materials outside Fabry–Perot cavity

The extinction ratio and insertion loss of spatial light modulator are subject to the material problem, thus limiting its applications. One reflection-type silicon-based spatial light modulator with high reflective materials outside the Fabry-Perot cavity is demonstrated in this paper. The reflectivity values of the outside-cavity materials with different film layer numbers are simulated. The reflectivity values of 6-pair Ta2O5/SiO2 films at 1550 nm are experimentally verified to be as high as 99.9%. The surfaces of 6-pair Ta2O5/SiO2 films are smooth: their root-mean-square roughness values are as small as 0.53 nm. The insertion loss of the device at 1550 nm is only 1.2 dB. The high extinction ratio of the device at 1550 nm and 11 V is achieved to be 29.7 dB. The spatial light modulator has a high extinction ratio and low insertion loss for applications.

Scheme for Implementing Quantum Cloning Restoring Machine in Cavity QED

We propose an experimentally feasible scheme for implementing quantum restoring machine of the optimal universal 1→ 2 quantum cloning machine in the context of cavity QED. In our scheme, two atoms （the clones） simultaneously interact with a cavity field, and meanwhile they are driven by a classical field. Then an arbitrary unknown input state can be restored in the ancilla by applying appropriate unitary local operation.

Characteristics of selective oxidation during the fabrication of vertical cavity surface emitting laser

Taking into account oxidation temperature, N2 carrier gas flow, and the geometry of the mesa structures this paper investigates the characteristics of selective oxidation during the fabrication of the vertical cavity surface emitting laser （VCSEL） in detail. Results show that the selective oxidation follows a law which differs from any reported in the literature. Below 435℃ selective oxidation of Al0.98Ga0.02As follows a linear growth law for the two mesa structures employed in VCSEL. Above 435℃ approximately increasing parabolic growth is found, which is influenced by the geometry of the mesa structures. Theoretical analysis on the difference between the two structures for the initial oxidation has been performed, which demonstrates that the geometry of the mesa structures does influence on the growth rate of oxide at higher temperatures.

一种三腔耐高压TPICC导管的设计

目前临床上应用的三腔PICC导管存在一定的局限性,使用率较低。因此,我院研究设计了一种采用隧道技术置入三腔PICC导管,应用于需置入三腔中心静脉的危重症患者,采用TPICC技术避免其在临床上的应用限制,提高了实用性及安全性。本文旨在阐述TPICC导管的设计方法及优势。

基于调制声场的腔体内壁黏附物清洗方法

传统超声清洗技术已经广泛应用于器件外表面的清洗,但对于微器件内部,如:狭缝、微腔体等,目前该技术仍难以胜任。其主要原因是自由微泡难以在器件内部指定位置稳定持续爆破。该文提出利用调制声场调控微腔体内声场极值的位置,使得微泡在声辐射力的作用下能够移动并停驻在腔体内壁附近位置,再采用瞬时高强度低频声场爆破微泡,其产生的微射流等实现腔体内壁黏附物分离并清洗的目的。该技术可以为医疗微管、光学仪器以及半导体芯片等精密器件的腔体内部清洗提供物理模型和技术基础。

1064nm超短激光脉冲的锁模获取与特性分析

为了获得1064 nm皮秒级的超短激光脉冲,探究其波形和功率特征以及泵浦功率和腔长对锁模特性的影响,使用SESAM(半导体可饱和吸收镜)设计相应的W型折叠腔实验系统进行分析,获得了重复频率为92.25 MHz的稳定锁模脉冲。实验结果表明,在腔长不变时,若泵浦功率过低,则锁模不会启动,若泵浦功率过高,则会观察到调Q不稳定及多脉冲现象,且在产生锁模效应的泵浦功率范围内,锁模脉冲的平均功率大小和泵浦功率大小是呈正相关的;在泵浦功率大小一定时,锁模脉冲的波形对折叠腔腔长的变化极为敏感,不足1 mm的腔长变化都会使波形出现较大的抖动,只有在一个极小的范围内才会出现稳定的梳状波。

柴达木盆地英雄岭构造带小断层和碳酸盐岩缝洞体识别地震勘探关键技术

针对柴达木盆地英雄岭构造带深层小断层和碳酸盐岩缝洞体识别,提出配套的地震勘探关键技术。首先,从资料采集方面,扩大观测方位,采用小组合激发和接收,炮、检点均匀布设,可提高小断层成像精度;在地震资料数据处理方面,采用OVT域多维保真压噪技术和巨厚表层Q补偿处理技术,可以提高地震资料信噪比、保真度,有效拓宽频带,提高分辨率;在地震资料解释方面,利用分方位数据体和人工智能断层识别技术,可有效提高小断层识别精度,利用各向异性强度属性可有效识别缝洞体。该技术可为其他类似地区提供参考。

可移动光学超稳腔的研制及其稳定性测试

可移动超稳腔可以减小环境振动对激光稳定性带来的影响,适合振动强度较大的运输条件。本文展示了一种由低膨胀系数玻璃制作的光学谐振腔,并测试了激光锁定到该可移动超稳腔的频率稳定性。支杆固定于金属热屏蔽罩内的机械设计使其具有良好的稳定性和可移动性。采用短延迟自外差干涉法测量了激光器锁定到超稳腔后的线宽,并且借助振动平台测试其稳定性。实验发现锁定后的激光器线宽和振动频率存在线性关系,激光器线宽会随着振动加速度增大出现饱和效应。去除振动时激光线宽可以恢复到无振动时的数值,证实该超稳腔具有较高稳定性。

手工制作在耳解剖教学中的应用

目的 探究手工制作耳解剖教学在低年资耳鼻咽喉头颈外科住院医师中的应用效果。方法 2019年1月—2022年12月,选取22名海军军医大学第一附属医院耳鼻咽喉头颈外科低年资住院医师,分为传统教学组(n=11)和手工制作教学组(n=11)。传统教学组仅接受多媒体幻灯教学,手工制作教学组在教师的带领下同步手工制作解剖模型并接受理论讲解。授课结束后,2组均完成理论考试和自制的主观调查问卷,进行教学效果评估和主观评估。结果 手工制作教学组的平均理论考试成绩高于传统教学组,差异有统计学意义(P <0.05)。手工制作教学组对讲授知识的主观易接受程度、解剖知识掌握程度、教学方式激发学习兴趣程度、思维能力培养及总体教学满意度均显著优于传统教学组,差异有统计学意义(P <0.05)。结论 手工制作能够显著提高耳鼻咽喉头颈外科低年资住院医生的耳解剖教学效果,提高学习兴趣,并有助于培养思维能力。

电针与神经肌肉促进技术联合用于脑卒中后吞咽障碍患者对总体康复效果及安全性的影响

目的:分析电针与神经肌肉促进技术联合用于脑卒中后吞咽障碍患者对总体康复效果及安全性的影响。方法:采取便利抽样法选取2022年1月~2023年1月本院收治的88例脑卒中后吞咽障碍患者,根据随机数字表法分为观察组和对照组各44例,对照组予以神经肌肉促进技术治疗,观察组予以电针与神经肌肉促进技术联合治疗,4周后比较两组患者临床疗效、康复效果、咽腔收缩情况及安全性。结果:观察组总有效率为90.91%,高于对照组的75.00%(P<0.05);治疗后,观察组MMASA评分、FIRS评分均高于对照组,SSA评分则低于对照组(P<0.05);观察组浓流质与稀流质饮食时咽腔收缩持续时间均长于对照组,咽腔收缩率则低于对照组(P<0.05);两组不良反应发生率差异无统计学意义(P>0.05)。结论:电针与神经肌肉促进技术联合用于脑卒中后吞咽障碍患者可取得显著效果,不仅能提升其疗效,促进吞咽功能康复,还能改善患者咽腔收缩情况,同时安全性高。

The technique of detecting the laser-ultrasonic vector displacement with a confocal Fabry-Perot interferometer waves in a plate

Generally, a confocal Fabry-Perot interferometer is only able to detect the out-of-plane component of a displacement field; while the in-plane component often has the information about the material which cannot be found in this out-of-plane component. In this paper, based on a confocal Fabry-Perot interferometer set-up for detecting the out-of-plane component of a laser generated acoustic field, a technique is developed to detect both the out-of-plane and in-plane displacement components simultaneously with a novel two-channel confocal Fabry-Perot interferometer.

探地雷达对道路空洞修复效果探测的应用

随着各大城市道路空洞探测项目的实施,探测成果丰硕,有效减少了道路塌陷事故,也推动了空洞修复技术的发展,但修复后的空洞仍频繁出现沉陷甚至塌陷事件,主要原因是空洞修复技术的不足,当时又无法得知修复效果。为保证空洞修复后不再出现新空洞,空洞修复后的雷达探测成为检测修复效果的有效手段。探地雷达由于其分辨率高、速度快、成果直观且可实时反应地下情况,是目前常用的探测手段。本文首先阐述了目前普遍使用的空洞修复技术,并对修复后空洞进行探地雷达正演模拟,最后结合工程案例,分析探测效果。结果表明,探地雷达对大多数修复技术的效果探测准确可靠,但对高聚物注浆修复效果评价需结合FWD(落锤式弯沉仪)等其他无损检测技术,本文所提出的探测方法可为同行开展相关工作提供借鉴。

利用盐腔充填处置工业固废研究进展

面对越来越严峻的工业固废处置形势,本文提出了利用盐腔充填处理工业固废,该技术不仅能安全、环保、经济的处理大宗工业固废,还能有效抑制井下盐腔体积收缩,控制地表沉降等地质灾害。本文从工业固废的产生及利用现状出发,对比分析了盐腔处置工业固废的优势,总结了国内外利用盐腔处置工业固废的案例,以期为工业固废处置提供一种新思路。

宫腔镜下冷刀技术治疗宫腔粘连患者子宫内膜厚度及效果的分析

目的分析宫腔镜下冷刀技术对宫腔粘连的治疗效果及对子宫内膜厚度的影响。方法选择2022年5月—2023年5月福建医科大学附属福州市第一医院妇科治疗宫腔粘连的100例患者作为研究对象,以电脑软件随机抽取其中50例作为对照组,另外50例作为研究组。对照组采取宫腔镜下等离子电切手术,研究组采取宫腔镜下冷刀微剪手术。对比2组的临床疗效、手术用时、住院天数、膨宫液使用剂量、术中失血量、术后3个月复发率以及治疗前后的宫腔容积和子宫内膜厚度、并发症。结果研究组总有效率为98.00%,高于对照组的82.00%,差异有统计学意义(P<0.05);术后3个月研究组复发率为4.00%,对照组为24.00%,组间对比,差异有统计学意义(P<0.05)。与对照组比较,研究组的住院天数和手术用时相对更短,膨宫液使用量和术中失血量相对更少,差异有统计学意义(P<0.05)。采用一般线性模型对治疗前后不同组别的患者宫腔容积和子宫内膜厚度的对比分析,治疗前,2组宫腔容积、子宫内膜厚度比较,差异无统计学意义(P>0.05),治疗后,研究组具有比对照组更大的宫腔容积和更理想的子宫内膜厚度,差异均有统计学意义(P<0.05)。研究组无并发症发生,对照组虽有2例但与研究组相比,差异无统计学意义(P>0.05)。结论相较于宫腔镜下等离子电切手术,宫腔镜下冷刀技术对宫腔粘连的治疗效果更加显著,带来的创伤更小,安全性更高,患者术后恢复快,复发率低,且宫腔容积和子宫内膜厚度也可以得到更加显著地改善。