1，组件选择<ol><li>在适当的波长为感兴趣的原子选择一个二极管。所选的二极管是单模（SM和有足够的功率应用程序，这一点至关重要。防反射涂层二极管是理想的。这些二极管不会化酶不加外腔，他们被明确为ECDL操作而设计。它们具有显著更好的性能，尤其是对于应用在扫描激光的波长是很重要的。这里所用的激光二极管中列出材料清单）。 如麦克亚当等 3，ECDL必须被设计成紧密地适合二极管和准直透镜。机械稳定性和热接触是激光的良好运行至关重要。为便于施工，最​​小的加工，成功已经使用了集成透镜管（材料清单）二极管激光器安装。 </li><li>选择一个镜头瞄准二极管。它重要的是，数值孔径相媲美或比二​​极管的数值孔径越大，否则会有重大损失。最二极管具有高数值孔径（&gt; 0.5）和需要的非球面透镜，否则畸变会导致非常低的反馈效率。确保透镜是防反射涂覆在工作波长中，选择一个透镜具有长焦距，以增加光束尺寸在光栅和一个设计波长附近的工作波长，以减少像差。请参阅材料清单的展示系统中使用的镜头。 </li><li>选择适当的外部光栅，用于对激光二极管的频率范围和光栅调谐臂中心角。光衍射成第一级的波长，利特罗配置，通过λ= 2 D SIN（θ），其中，d是光栅线间距给出，θ为入射在光栅角度和λ的波长21（ 图1B）。有衍射的两种主要类型的光栅，全息和统治，都可能会开辟与否。根据光栅衍射的电源类型可能大幅变化。目的是为全息光栅与在20-30％之间的衍射效率。请参阅材料清单的展示系统中使用的光栅。 </li><li>用最简单的设计易于管理 - 复杂性往往意味着不稳定。也有ECDL设计一个庞大的数字，但最简单的就是利特罗3,5,7,22。阅读有关文件，并决定是否大模式跳自由范围（频率范围该二极管可连续调不突然跳跃到不同的频率），一个很窄的线宽或降低指点变化是最重要的应用程序。 ECDL开始设计之前获得尽可能多的信息成为可能。通常情况下，光栅ECDL是足够有余的原子物理中的应用。 </li><li>要认识到，一个ECDL的性能是最强烈的植根于驱动该二极管的电流和稳定的激光器的温度的电子是很重要的。如果没有一个良好的集电子产品的机械设计将下进行。包括在表1不同电流和温度控制器的比较。的电流噪声更低，更好的激光将执行23。 </li></ol> 2。大会<ol><li>对于本文的目的，起点ECDL组件将被安装在一个热电冷却器（TEC）的完整ECDL机械系统没有频率选择元件（ 如光栅和激光二极管）。 </li><li>通过将激光二极管在其各自的安装孔开始，并使用它的安装环固定。要小心，不要过度扭紧安装环。它应该是温暖的，但不紧绷。 </li><li>前激光二极管连接到所述电流供给，车CK上的二极管规格表为阳极，阴极和接地引脚分配。这种变化从二极管和二极管把电流通过二极管向后必摧之。 <ol><li>激光二极管是低电压器件，通常5-10 V（最大值），并且必须小心，以确保无静电放电给他们。这是很好的做法处理二极管时佩戴接地腕带，并安装一个保护电路（ 如图2）激光二极管两端引脚，以防止高电压。该二极管可以和接地引脚应永久接地，并且利用细导线可以减少机械振动的耦合帮助。 </li></ol></li><li>根据二极管规格表中的值设置最高和最低温度和二极管控制器上最大的二极管和TEC的电流限制。如果最低工作温度低于露点实验室然后用〜2℃ABO的最低温度已经露点。这将避免水汽凝结。 </li><li>二极管规格表通常有一个波长与温度图在给定的二极管电流。使用该图作为参考，以初步确定二极管温度（和电流）来匹配感兴趣的波长。如果温度与波长曲线图是不可调节设定温度至室温。 </li><li>打开温度控制器上，并允许温度稳定。 </li><li>打开（ON）二极管，并转动电流向上，以便在输出光束可以被清晰地观看卡观察到。使用红外卡，查看梁。 </li><li>插入非球面准直透镜和通过调整二极管和透镜之间的距离准直激光二极管。为了保证良好的准直确保光束具有清晰的路径，理想高度&gt; 3米，并调整镜头位置，直到光束直径刚过ECDL，并在光束路径的终点都是一样的，一定要检查光束I不是聚焦在沿路径的任何点。 </li><li>检查偏振从二极管激光器是在对衍射光栅（S或P）的所需平面。在大多数情况下，二极管的极化是沿着椭圆光束形状的短轴，但它是很好的做法，检查偏振轴使用偏振分束器。 <ol><li>如果光束轴线不处于所希望的平面内，松开二极管安装环和旋转的二极管，直到正确的取向得以实现。有些ECDL的设计让这种与激光来完成，并连接到电流源和别人不一样。如果当前的电源线必须拆除旋转二极管，关闭电流供应，控制箱和导线。该ECDL温度控制可以在此过程中保持。记住处理二极管时始终佩戴接地带。 </li><li>如果有必要重新定位二极管重复上一步重新准直二极管。 </li></ol></li><li>光栅的衍射平面通常标记由生产商以垂直于光栅线的箭头和在闪耀反射的方向。双通过观察从宽带光源的反射，如灯泡，作为角度的函数来检查。 <ol><li>如果光栅举行箭头指向背对着观察者和宽波段光源在头上，反射光会在颜色改变，因为光栅角度的函数。 </li><li>安装光栅使箭头指向背面朝向二极管，从而调整光栅的角度而变化的波长反射回二极管（ 图1A和1B）。 </li></ol></li><li>一旦光栅方向已经证实胶水使用快速固化胶，如乐泰的ECDL调整臂的光栅。 </li></ol> 3，反馈对齐<ol><li>放置一个可视卡相一致的ECDL输出是是。这将被用于监控激光功率的调整在该衍射光束的指向。也可以使用功率计，但在它的响应速度较慢。 </li><li>调节在二极管控制箱设置电流到刚好低于阈值电流为反射前方端面二极管和1/3的最大电流为AR涂覆的二极管增益芯片。反光前端面二极管将不会对他们的规范或数据表的阈值电流，同时AR镀膜增益芯片没有。 </li><li>调整光栅臂的角度在水平方向和垂直方向，引导衍射光束返回到二极管，有效地使外部反馈空腔。当光束被引导到激光二极管还会有显著增加输出功率，可观察到如在观看卡或功率时使用功率计或光电二极管测得的显着增加的显着增加或明亮的闪光。 <ol><li>一个可视卡不是很定量测量ØF功率，因此它可能是必要的，即可逐渐降低激光二极管的电流和调整反馈光束直到上述行为可以在尽可能低的电流可以看出。 </li><li>调整所述准直透镜的焦点或轴向位置，以优化聚焦在二极管面可以进一步降低阈值，提高输出功率后，它会是必要的水平和垂直方向重新优化的光栅角。 </li></ol></li></ol> 4，初始频率选择<ol><li>用于对激光的初始频率对应的波长的&lt;1纳米的精确度的绝对测量和理想&lt;0.1 ​​nm的是理想的。这个粗测频将使它更容易调谐激光频率上的原子跃迁在后面的步骤。有许多选项，包括使用波长计，光频谱分析仪，光谱仪，或用照相机单色器。确保校准正确使用设备或检查其Calibration例如，使用氦氖激光器。可替换地，粗的频率调节通常可以通过步行光栅角和电流，而激光是扫描直到从蒸汽基准单元的吸收或荧光信号可以看出实现。 <ol><li>通常一个辅助光束从主光束采摘下来，用玻璃楔形棱镜或λ/ 2波片和偏振分束器，将作为一个输入的波长计。此光学系统设置是出现在图1D。请参阅材料清单在这个演示中使用的材料。 </li></ol></li><li>调整ECDL直到获得所需的输出波长。二极管的驱动电流，温度，光栅角和外腔长度，均会影响激光频率24（ 图3）。 <ol><li>通过调整光栅角度开始，要么通过手工或使用压电。其次，调整二极管电流。 </li><li>如果所需的frequeNCY是光栅扫描范围的蓝，二极管的温度应降低，反之亦然，如果所期望的波长是红色的。 </li></ol></li></ol> 5，精细频率调节和频率锁定<ol><li>设置饱和吸收光谱上的ECDL输出使用图1F 3,14,17配置。激光后立即使用的光隔离器是必不可少的（ 图1C）。避免背反射到激光，这可能会导致不稳定是很重要的。使用引用的单元格，包含感兴趣的原子饱和吸收光谱法是一种简单的方法来锁定一个激光窄原子跃迁25。 <ol><li>确保引用的单元格是在一个角度，以避免背部反射和镜面反射复古光束通过回用最大重叠的蒸汽室。双通传输功率可以使用光电二极管作为电子监视CDL波长扫描。 </li></ol></li><li>最二极管控制器将具有一个内置的扫描功能，将通过调整光栅的压电电压，因此在光栅角和外腔长度或者通过调整二极管电流扫描的波长。的宽度，扫描偏移和激光器温度和电流应被调整，直到吸收信号可以在连接到光电检测器的范围内进行观看。当激光扫描过的原子跃迁应该可以看到激光束路径在汽细胞发出荧光或闪烁，用肉眼或通过一个红外观众。 </li><li>每单位面积的参考光束对饱和吸收光谱中的功率必须等于或高于饱和强度的原子跃迁。使用的λ/ 2波片的偏振分束器之前，以增加功率，直到一个明确的吸收信号可以看出。饱和强度的计算可以在脚16被发现。 </li><li>用激光扫描在780nm的铷原子跃迁，宽多普勒加宽吸收信号应该可以看出，〜5GHz的宽度，与几个急剧过渡〜10兆赫烧脚16（ 图4）。最小化用于产生饱和吸收信号的功率是必要的，以减少功率展宽和产生更清晰的功能来锁定。 </li><li>为了锁定ECDL频率，误差信号是必要的。通过将参考单元周围的线圈， 如图5和10的振荡磁场中，塞曼水平和跃迁从而中的频率被调制。在这种情况下，电流通过塞曼线圈被调制在约250千赫的1〜G的大小</li><li>从与从函数发生器的调制信号的饱和吸收光检测器混合的吸收信号。当从混频器的输出被认为在范围应该是一个错误信号SImilar参照图4的误差信号的幅度将取决于两个混合信号之间的相对相位。旋转的λ/ 4分束器的蒸气细胞之前来调整相位。 </li><li>逐步减少扫描范围和调整偏移到中心扫描在感兴趣的转变与目前还没有其他的转换。 </li><li>比例-积分-微分（PID）回路（例如见麦克亚当等 3）然后可以用于利用所述误差信号，锁定ECDL波长。将PID增益应减少至低于在该振荡是由（利用频谱分析仪或傅里叶误差信号迹线的变换例如 ）寻找调制的误差信号的存在下观察到的点。 </li></ol> 6，线宽测量<ol><li>为了获得准确的线宽计测，有必要有或者是已知的窄线宽光源（另一个激光与升inewidth显著小于ECDL），两个相同的ECDLs或与ECDL的相干长度长相比的延迟线的。这里有两个ECDLs会干扰测量线宽。另外，也可以更容易地锁定到通过原子转移或一个法布里 - 珀罗腔，并适合于锁定环路的带宽以上的噪声产生的共振。 </li><li>锁定两个激光器，以不同的超精细跃迁，最好在100 MHz偏移。这将电子噪声的影响最小化。 </li><li>模式下，功率和偏振匹配的两束光，并使用50/50，非偏振分束器干涉在一起。对准光电检测器所产生的光束。上的光检测器的输出信号应该是一个正弦波与两个激光器的频率的频率偏移。它可能是必要的，以衰减或散焦所产生的光束，以便不破坏或饱和的光电二极管。 <ol><li>两束跳动的重叠将决定边缘续RAST线宽测量过程中所观察的范围。如果条纹对比度差，花费额外的时间提高了模式匹配的光束和重叠在分束器和检测器。一个好的方法是使用两个虹膜&#39;重叠的两束光束，或销孔，通过相对大的距离分隔开，约1微米。 </li></ol></li><li>这将是很难解决的一个范围的频率波动。为了获得最佳的测量使用频谱分析仪，这将给一个福格特配置中心的拍频的线宽 Δ 楼等于卷积激光线宽（ 图6）。一个很好的近似轨迹可以适合于高斯和拟合得到的线宽。测得的噪声或线宽将取决于收购或整合的时间，这可以通过调节频谱分析仪的分辨率带宽进行设置。出于这个原因，它引用了M当引用的积分时间是很重要的easured线宽。 </li></ol>

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作者什么都没有透露。具体的产品和公司引文仅用于澄清的目的，并非背书作者。

该出版物表明了如何从拆卸ECDL通过对齐和频率锁定移动，以产生激光线宽的测量。机械设计及电子设备，如PID伺服系统，二极管驱动器和温度控制器的设计过于专业要在这里讨论，但都引用了出版物1,3,5得到了全面的讨论。 虽然二极管ECDL的已经成为原子物理实验室，物种和转场，这些不可同日而语可以达到有限的主食。很大的进展已经取得了扩大的波长范围从基础的二极管激光器然而目前许多差距仍然特别是在紫外线。 ECDL系统的功率限制继续限制他们的应用程序。裸单模二极管不等功率从μWatts到100 mWatts系列的。此外，锥形放大器可以被添加到一个ECDL系统增加单模激光的总功率到瓦特的水平。如果单模权力比一瓦或其他波长大得多，需要另一种激光的架构是必需的。这些包括光纤激光器26，固体激光器27如TiSaph激光器，或者它们可以依赖于非线性频率转换处理27，如拉曼激光器，四波混频，和频产生，或光学参量振荡器。 此出版物集中于一个锁定机构是依赖于一个原子蒸气细胞。对于在原子物理的简单玻璃蒸气细胞许多应用中，如这里所讨论的，可能不可用，例如对于物种如镱的情况。许多其它技术用于获得与各种物质的参比样品已被证实，例如，热原子束，放电灯中，缓冲气体的细胞，碘的细胞，并溅射细胞。 这种激光系统的设计本质上是限于≈30 kHz的线宽28，通常接近100千赫。如果应用程序需要一个更窄的线宽其他稳定技术或替代激光设计26顷必需的。 每当与光学系统的工作，清洁是最重要的。这是很好的做法，当第一次被介绍给和处理的手套戴，以防止意外接触光学表面的光学元件。如果光学元件被划伤它不应该在激光系统中使用。在大多数情况下使用的光学指纹或灰尘可以用丙酮或压缩空气分别进行清洗。任何缺陷的光学表面可以与将引入的损失和潜在的噪声进入系统。光学支架应固定在光学台在​​任何时候都应该坚决囫囵吞下一次到位。 当对准光学器件如波片和偏振分束器，确保光入射接近垂直于光轴的表面上，同时AVOiding反射回到激光器。随着入射角从90°偏离这些光学元件的行为从理想变得越来越远。为了尽量减少像差，最大限度地提高数值孔径的光束应该总是通过镜片的中心行进，并垂直于镜头。与此相反，一个蒸气细胞应该被放置在一个很小的角度入射的光束，以避免标准具效应。出于这个原因，许多汽细胞具有非平行端面的制造。 这里所用的激光器是类3B。即使杂散反射对眼睛的损害的可能性。这种类型的激光器的工作只能由经过培训的人员熟悉激光器的危害进行。激光防护镜应该在任何时候都可以穿。切勿直接小看任何激光的光学对准的路径，并采取特别小心，以避免产生危险的镜面反射了光学元件。总是积极地终止束线环电纳克梁转储。

测量和操纵原子的量子态是原子物理的心脏，需要解决的原子的电子态之间转换的具体能力。例如，考虑铷，一个典型的多使用碱性原子。在这里，光耦合地面的波长和第一激发电子态为〜780纳米（384赫兹）和激发态的寿命，由于自发发射〜26纳秒给人的6兆赫4的吸收线宽。因此，与至少一个部分在108的频率稳定性的光源是必需的，以可靠地解决这一过渡。 前ECDLs，染料激光器和钛蓝宝石激光器的发展进行了通常用于原子物理。这些是大的，昂贵的，复杂的系统，提供光学增益在一个大的带宽，因此可以进行调节，以重叠的原子跃迁。用便宜的，简单的二极管激光器设计的无线替代这些增益介质的潜力第一个带隙匹配所需的波长是在20世纪80年代初1,2确认。简单，容易地创建实现100 kHz的线宽是很好的理解和共同的地方由20世纪90年代3,5,6早期的设计。许多不同的配置和设计已被证明与各的优点和缺点。也许最常见的配置是利特罗3,5,7,8和利特曼9配置。这样的讨论集中在最简单的，在图1A所示的利特罗配置。 若干调谐机制被同时使用，实现了高精度的激光频率。首先，一个二极管是必需的带隙产生足够的增益在所需的波长在一个可以实现的操作温度。典型的激光二极管将有增益超过几纳米（太赫兹）。其次，一反射式衍射光栅是角度调整提供光学反馈到二极管在所希望的波长。取决于光栅，二极管，聚焦透镜使用，它们的对准，光栅将选择的通常50-100千兆赫的频率范围。激光器的振荡频率在共振波长与外部激光腔（二极管后侧面和光栅之间）。调谐跨越波长空腔长度允许激光被经过一自由光谱范围（C /（2L））调谐围绕光栅增益峰值，其中c是光且L的速度，是腔长度，通常为1 - 5厘米（FSR 3-15千兆赫）。当两个腔模式从光栅峰值波长反馈了类似的波长的激光可以运行多。作为振荡腔模进一步从增益峰值比其相邻模式调谐激光器将模式跳限制调谐范围。腔模相对于所述光栅模式的行为可以看出，在图3中的模式跳自由调谐范围为ECDL一个关键的性能指标。通过同时调整光栅角度和腔长，可以跨越许多自由光谱范围内连续地调谐无跳模，使得定位和锁定到光谱特征更容易8。空腔用于锁定的光路长度的电子调谐可以通过使用压电致动器（ 图1A）（扫描带宽〜1千赫）调谐光栅角度/位置和调整二极管电流，主要调节折射率的组合来实现二极管（扫描带宽≥100千赫）的索引。使用激光二极管，而不是防反射（AR）涂层的增益芯片的增益介质。添加加激光二极管的内部腔响应可具有100-200千兆赫的典型的自由光谱范围的附加的复杂性。在这种情况下，空腔必须是温度调谐，以匹配来自光栅的响应。使用激光二极管，而不是一个AR镀膜增益芯片将大大减少跳模自由吨uning范围内，除非有一种方法来同步调整二极管的电流或温度。最后，实现了线宽小于100 kHz的小心注意更好地必须支付消除其他噪声源。这需要坐骑谨慎机械设计，以尽量减少声学振动，mK的水平温度稳定，在≤30 nA的水平，并仔细调整所有锁定的增益回路10 有效值二极管的电流稳定。选择合适的电子器件的应用程序是一样的激光和光学设计一样重要。二极管控制器和规范的列表可以在表1中可以找到。 一旦稳定激射已经实现，接下来的要求是，锁的激光频率与参考如原子跃迁，光学腔或其他激光。这消除缓慢漂移，如小的温度波动的影响，从根本上消除噪音的频率与在锁定环路的带宽。有锁已被开发用于获得误差信号，每个适合于一个特定的参考系统技术的无数。可以通过将两个激光器的光束分离器获得相位锁定两个激光器的误差信号。磅德雷弗大厅11或倾斜锁12可用于锁定到空腔中。锁定到一个原子吸收线DAVLL 13或饱和吸收光谱3,14与电流调制10，塞曼调制10，或倾斜锁15可组合使用。 一个ECDL的使用饱和吸收塞曼调制在汽细胞铷跃迁的锁定将在这里说明。如果一个低强度的光束穿过一个铷蒸汽细胞在室温下，频率被调谐为在780nm的原子跃迁附近的数多普勒加宽吸收特性〜500 MHz的宽将观察到的，而不是6 MHz宽的自然线宽（计算自然和多普勒线宽可以在脚部16中找到）。然而，如果该光束被复古的反射，在第二遍将不会对共振吸收少的原子与一个零纵向速度已经由所述第一通17部分地激发。其它频率将不同速度的人群被吸收在每次通过，因此吸收不会饱和。在这样一个明显的传输特性重叠在多普勒加宽吸收跃迁，其宽度大约自然线宽可以得到。这提供了一个尖锐的绝对频率参考锁定。的原子跃迁的频率可以利用塞曼效应通过抖动的磁场的大小在参考单元进行调制。一种合适的均匀的磁场可以用一个电磁线圈设置为如图5中所示来制备。电混合用饱和吸收传输的调制波形生成可以用来调整二极管电流与集成来调整压电电压的误差信号。因此，激光可能被锁定到过渡，而无需调制激光频率。 一个ECDL的线宽通常是通过在分束器18的干扰的两 ​​个相同类型的频率锁定的激光器测量。激光器之间的差拍频率，然后利用快速光电二极管和一个RF频谱分析仪测量。噪声频谱超出了锁定环路带宽，然后安装到配置文件的福格特（高斯和洛伦兹的卷积）。从不同的激光器的噪声增加正交。在两个相等的激光器而言，这给出了一个√装线宽（2）倍单激光线宽。如果激光可与已知的线宽比从ECDL预期显著较小，它是E的调谐范围内CDL，那么，可以用来代替。通常用于测量线宽的另一种方法是延迟自零差技术19,20，其中束的一部分沿着光延迟线发送诸如纤维，然后混合，在光束分离器与激光。这种技术依赖于延迟比下测量的激光的相干长度更长。这非常适用于嘈杂的激光器，但对于一个100 kHz线宽激光器的相干长度约3公里，其中开始变得不切实际。或者，在一个饱和吸收单元或一个法布里 - 珀罗腔的原子跃迁可用于提供激光线宽计测的频率参考。在该系统中，激光的频率将需要坐在醚的线性部分的饱和吸收或法布里 - 珀罗共振，而不是允许的频率进行扫描。通过测量光电二极管的信号噪声，并知道共振线宽，频率噪声可以被发现。李下限newidth测量，然后由传输共振的斜率的限制。 高阶激射模的存在可以通过看强度噪声​​的自由光谱范围中的频率利用RF频谱分析仪或通过使用扫描法布里 - 珀罗或光学频谱分析仪的分辨率高于自由光谱更好的被检查范围ECDL的。粗调谐范围可通过测量功率作为波长的函数（使用波长计，单色器，或光学频谱分析仪），同时使用光栅调谐激光穿过它的极限进行测定。的跳模自由调谐范围使用扫描法布里 - 珀罗腔，其中一个模式一跳可以被检测为在频率上的不连续跳跃通常测定。

<table border="0" cellpadding="0" cellspacing="0" width="870">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="20">
			<td height="94" rowspan="3" style="height:94px;width:253px;">Laser Diode 
			(Rubidium, 780nm)</td>
			<td rowspan="3" style="width:181px;">Roithner</td>
			<td rowspan="3" style="width:195px;">ADL-78901TX</td>
			<td rowspan="3" style="width:241px;">Various wavelengths, powers, case sizes and AR coatings are available (Thor Labs, Eagle Yard Photonics, Rothnier)</td>
		</tr>
		<tr height="21">
		</tr>
		<tr height="53">
		</tr>
		<tr height="61">
			<td height="61" style="height:61px;width:253px;">Diffraction Grating 
			(Rubidium, 780nm)</td>
			<td style="width:181px;">Newport</td>
			<td><a href="http://search.newport.com/?q=*&amp;x2=sku&amp;q2=05HG1800-500-1">05HG1800-500-1&#160;</a></td>
			<td style="width:241px;">Holographic or rullered 
			&#160;(Optional blazing) 
			(Thor Labs, Newport)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">Viewing Card</td>
			<td style="width:181px;">Thor Labs</td>
			<td>VRC5</td>
			<td style="width:241px;">Infared viewing card</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:253px;">Diode&#160; Lens</td>
			<td style="width:181px;">Thor Labs</td>
			<td>C330TME-B</td>
			<td>Coated for 780 nm</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:253px;">Glass Wedge</td>
			<td style="width:181px;">Thor Labs</td>
			<td>PS814</td>
			<td>10 &#176; wedge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">1/2 Waveplate</td>
			<td style="width:181px;">Thor Labs</td>
			<td>WPH10M-780</td>
			<td style="width:241px;">780 nm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">1/4 Waveplate</td>
			<td style="width:181px;">Thor Labs</td>
			<td>WPQ10M-780</td>
			<td style="width:241px;">780 nm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">Rotation mounts</td>
			<td style="width:181px;">Thor Labs</td>
			<td style="width:195px;">RSP1C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">PBS</td>
			<td style="width:181px;">Thor Labs</td>
			<td style="width:195px;">PBS252</td>
			<td style="width:241px;">780 nm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">Isolator</td>
			<td style="width:181px;">Thor Labs</td>
			<td style="width:195px;">IO-5-780-HP</td>
			<td style="width:241px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">Vapor Cell</td>
			<td style="width:181px;">Thor Labs</td>
			<td><a href="http://www.thorlabs.com/thorProduct.cfm?partNumber=GC25075-RB">GC25075-RB</a></td>
			<td>Rubidium&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">Photo Detector</td>
			<td style="width:181px;">Moglabs</td>
			<td>PDD-001-400-1100-&#955;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">Scope</td>
			<td style="width:181px;">Tektronix</td>
			<td style="width:195px;">TDS1001B</td>
			<td></td>
		</tr>
		<tr height="78">
			<td height="78" style="height:78px;width:253px;">Wavemeter</td>
			<td style="width:181px;">Yokogawa</td>
			<td style="width:195px;">AQ-6515A</td>
			<td style="width:241px;">We use an optical spectrum analyzer but a cheaper wavemeter would also be sufficient</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">Electronic spectrum analyzer</td>
			<td style="width:181px;">Agilent</td>
			<td style="width:195px;">E4411B</td>
			<td style="width:241px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:253px;">&#160;IR Viewer</td>
			<td style="width:181px;">FJW Optical Systems Inc</td>
			<td>84499A-5</td>
			<td style="width:241px;">Infared viewer</td>
		</tr>
	</tbody>
</table>

construction and characterization of external cavity diode lasers for atomic physics

由于他们在20世纪80年代后期，开发便宜的，可靠的外腔半导体激光器（ECDLs）已经取代了复杂而昂贵的传统染料和钛蓝宝石激光器作为原子物理实验室1,2的主力激光器。其多功能性和整个原子物理中的应用，如吸收光谱和激光冷却1,2大量使用使得它必须传入学生获得这些激光器的坚定实践的理解。本出版物是建立在开创性的工作，威曼3，更新组件，并提供了视频教程。一个ECDL的设定，频率锁定和性能特征进行说明。讨论元件选择和两个二极管和光栅的正确安装的，在腔体内影响模式选择的因素，以达到最佳的外部反馈，光学设置为粗，细频率敏感的测量，激光locki的简要概述适当的调整毫微技术，和激光线宽测量也包括在内。

有参与调整，频率锁定和表征ECDL的线宽5个主要步骤。它们是：取得从光栅反馈，并使用它来设置一个波长计测得的粗ECDL频率，观察激光吸收在引用单元格，查看周围的饱和吸收光谱设置自然线宽分辨率的原子跃迁，获得了各地所需的过渡，并锁定它，最后观察跳动的音符两个激光器和测量激光线宽误差信号。第一步成功完成，相当平凡，当为已读的波长计的波长对应于感兴趣的原子跃迁。当试图实现吸收，在参考单元，花期可以沿着光束路径中的细胞与一个IR观察者观察时的过渡被击中。如果ECDL是扫描单元格将闪烁。饱和吸收信号可能很难发现磨片<html> n个第一对准，因为相比于多普勒吸收峰的传输线路可以是非常小的。当峰，类似于图4中所示，可以看出，在饱和吸收系统是否正常工作。通过调整相位和扫描参数相似，在图4中所示的误差信号应获得。为了测量ECDL线宽有必要获得两束光之间的拍频信号。作为光束变得越来越重叠正弦波将开始出现，所看到的从光检测器范围。保持对准，直至节点和反节点之间的对比度最大。当拍子信号，然后通过一个电子频谱分析仪的信号通过类似于图6应当看到。激光线宽可以从这个信号进行测量。完整的光学系统的设置可以看出，在图1中 。 <img alt="&lt;/ HTML">“图1”FO：内容宽度=“5英寸”FO：SRC =“/ files/ftp_upload/51184/51184fig1highres.jpg”SRC =“/ files/ftp_upload/51184/51184fig1.jpg”/&gt; 。图1完整的光学系统设置这是一个完整的光学设置为讨论的ECDL系统A的一个例子：这显示了ECDL的Littrow结构。一个百分比的光束入射在光栅上的，通常为20-30％，被衍射放回二极管。衍射角和反射角相等。光栅被安装到一个调谐阶段，使用压电来控制光栅角度B：从激光二极管的输出光束入射在光栅上以角度θ与0阶反射离开并在第一级衍射被送回沿着与入射光束的路径。 ，光学是位置和方向：衍射光的波长为λ= 2 D罪（θ）Littrow结构给出Çolator以减少不需要的信息反馈给激光二极管D：从激光箱的输出光束通过λ/ 2波片和PBS中并对齐到波长计。在反射和透射的光束的功率可以通过转动波片来调节E：用于实验束线。这条线将包含大部分激光的功率F：通过PBS传递一个参考光束或高于饱和强度，λ/ 4波片，参照气体单元，和复古反映它放回PBS。重要的是，两个光束是公重叠以获得适当的饱和光谱。波片将确保光的偏振的复古反射光束会从入射光束允许其退出分束器的另一端旋转90°上。 <a href="https://www.jove.com/files/ftp_upload/51184/51184fig1highres.jpg" target="_blank">点击这里查看大IMAG</a>Ë。 <img alt="图2" fo:content-width="2in" src="/files/ftp_upload/51184/51184fig2highres.jpg" width="200" /> 图2。激光二极管保护电路。举例保护电路为激光二极管电流。R 1 和 C 1形成基本的RC电路，并滤除高频噪声。D 1和D 2分别肖特基二极管和齐纳二极管。肖特基二极管，其具有快速的响应时间，在这里，以防止逆向电压和齐纳二极管，它具有较长的响应时间，被设计为允许电流通过，如果上面的激光二极管的最大工作电压，从而避免损坏激光二极管。各组分的典型值将是R 1 = 1Ω，C 1 = 1 MF，D 1 = 30 V，D 2 = 6 V.选择R1和C1的值，将限制上述二极管的电流调制带宽。这可以小于理想的，如果一个误差信号正在通过电流调制，而不是讨论塞曼调制而产生。 <img alt="图3" fo:content-width="5in" fo:src="/files/ftp_upload/51184/51184fig3highres.jpg" src="/files/ftp_upload/51184/51184fig3.jpg" /> 图3竞争模式中的ECDL绿：光栅衍射级≈50千兆赫取决于光栅的线宽红色固体：带线的激光二极管的内部腔模宽度≈10 MHz和自由光谱范围≈80千兆赫红色虚线：防反射涂层二极管的内部腔体。这些二极管将具有线宽在纳米范围内蓝：外部腔模式具有线宽≈500千赫和≈5 GHz的自由光谱范围。从3厘米长外腔。调整光栅角度将转向绿色曲线和Si的中心<html> multaneously改变外腔长度依次转移蓝色曲线为好。二极管的电流和温度的调整将转向红色曲线。 <img alt="图4" fo:content-width="5in" fo:src="/files/ftp_upload/51184/51184fig4highres.jpg" src="/files/ftp_upload/51184/51184fig4.jpg" /> 。图4饱和吸收光谱和相应的误差信号铷87下曲线：从多普勒免费光谱形成的更广泛的多普勒吸收峰饱和吸收峰。上部曲线：误差信号为相应的饱和吸收系统。该误差信号上面的标签对应的原子跃迁（F→F&#39;）。 JPG“/&gt; 图5。塞曼线圈。线圈缠在塞曼调制使用的铷蒸汽室。 <img alt="图6" fo:content-width="5in" fo:src="/files/ftp_upload/51184/51184fig6highres.jpg" src="/files/ftp_upload/51184/51184fig6.jpg" /> 由两个类似的激光形成的跳动音符的频谱分析仪图6。激光线宽。信号获取。从该图中，节拍为206.24兆赫和0.3兆赫的20毫秒的积分时间的线宽的频率。 <table border="0" cellpadding="0" cellspacing="0" width="635"><colgroup><col /><col /><col /></colgroup><tbody><tr height="24"><td height="24" style="height:24px;width:237px;"> 电流控制 </td><td style="width:123px;"> 范围 </td><td style="width:275px;"> 噪音 </td></tr><tr height="21"><td heighT =“21”的风格=“高度：21px;”&gt; 雷神实验室： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> LDC200CV </td><td> 0-20毫安</td><td> &lt;1μA（10赫兹-10兆赫） </td></tr><tr height="21"><td height="21" style="height:21px;"> LDC201CU </td><td> 0-100毫安</td><td> &lt;0.2μA（10赫兹-10兆赫） </td></tr><tr height="21"><td height="21" style="height:21px;"> LDC202C </td><td> 0-200毫安</td><td> &lt;1.5μA（10赫兹-1兆赫） </td></tr><tr height="21"><td height="21" style="height:21px;"> LDC205C </td><td> 0至500 mA </td><td> &lt;3μA（10赫兹-1兆赫） </td></tr><tr height="21"><td height="21" style="height:21px;"> Moglabs： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> DLC-202 </td><td> 0-200毫安</td><td> &lt;300尼龙/√Hz的</td></tr><tr height="21"><td height="21" style=“高度：21px;”&gt; DLC-252 </td><td> 0-250毫安</td><td> &lt;300尼龙/√Hz的</td></tr><tr height="21"><td height="21" style="height:21px;"> DLC-502 </td><td> 0至500 mA </td><td> &lt;300尼龙/√Hz的</td></tr><tr height="21"><td height="21" style="height:21px;"> 斯坦福研究系统： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> LDC500 </td><td> 0-100毫安</td><td> &lt;0.9μARMS（10赫兹-1兆赫） </td></tr><tr height="21"><td height="21" style="height:21px;"> LDC501 </td><td> 0至500 mA </td><td> &lt;4.5μARMS（10赫兹-1兆赫） </td></tr><tr height="21"><td height="21" style="height:21px;"> TOPTICA： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> DCC百分之一百一</td><td> 0-100毫安</td><td> 200 nA的RMS（5 Hz至1 MHz的） </td></tr><tr height="21"><td height="21" style="height:21px;">直流Ç五百分之一百十</td><td> 0至500 mA </td><td> 1μARMS（5 Hz至1 MHz的） </td></tr><tr height="24"><td height="24" style="height:24px;"> 温度控制器 </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> 托尔实验室： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> TED200C </td><td> -45到145°C </td><td> ±2 mK的</td></tr><tr height="21"><td height="21" style="height:21px;"> Moglabs： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> DLC-202 </td><td> -40〜50℃ </td><td> ±5 mK的</td></tr><tr height="21"><td height="21" style="height:21px;"> DLC-252 </td><td> -40〜50℃ </td><td> ±5 mK的</td></tr><tr height="21"><td height="21" style="height:21px;"> DLC-502 </td><td> -40〜50℃ </td><td> ±5 mK的</td> &lt;/ TR&gt; <tr height="21"><td height="21" style="height:21px;"> 斯坦福研究系统： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> LDC500 </td><td> -55到150°C </td><td> ±2 mK的</td></tr><tr height="21"><td height="21" style="height:21px;"> LDC501 </td><td> -55到150°C </td><td> ±2 mK的</td></tr><tr height="21"><td height="21" style="height:21px;"> TOPTICA： </td><td></td><td></td></tr><tr height="21"><td height="21" style="height:21px;"> DTC 110 </td><td> 0-50°C </td><td> ±2 mK的</td></tr></tbody></table> 表1。二极管电流和温度控制器，各种公司的二极管电流和温度控制器，其范围和噪音水平。

Watch this Scientific Journal Video about Construction and Characterization of External Cavity Diode Lasers for Atomic Physics at JoVE.com

Construction and Characterization of External Cavity Diode Lasers for Atomic Physics

这是一个指导性文件，以指导的外腔半导体激光器（ECDLs），包括元件的选择和光学校准，以及频率的参考光谱和激光线宽测量原子物理领域应用的基础建设和诊断。

外腔半导体激光器的原子物理的构建与鉴定

Since their development in the late 1980s, cheap, reliable external cavity diode lasers (ECDLs) have replaced complex and expensive traditional dye and ...

construction-characterization-external-cavity-diode-lasers-for-atomic

Research

JoVE Journal

Engineering

27.4K 次观看.  The Australian National University. 这是一个指导性文件，以指导的外腔半导体激光器（ECDLs），包括元件的选择和光学校准，以及频率的参考光谱和激光线宽测量原子物理领域应用的基础建设和诊断。 

视频: Construction and Characterization of External Cavity Diode Lasers for Atomic Physics

Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view and for its considerable potential for practical applications. Slow light photonic crystal waveguides, in particular, have played a major part and have been successfully employed for delaying optical signals1-4 and the enhancement of both linear5-7 and nonlinear devices.8-11
Photonic crystal cavities achieve similar effects to that of slow light waveguides, but over a reduced band-width. These cavities offer high Q-factor/volume ratio, for the realization of optically12 and electrically13 pumped ultra-low threshold lasers and the enhancement of nonlinear effects.14-16 Furthermore, passive filters17 and modulators18-19 have been demonstrated, exhibiting ultra-narrow line-width, high free-spectral range and record values of low energy consumption.
To attain these exciting results, a robust repeatable fabrication protocol must be developed. In this paper we take an in-depth look at our fabrication protocol which employs electron-beam lithography for the definition of photonic crystal patterns and uses wet and dry etching techniques. Our optimised fabrication recipe results in photonic crystals that do not suffer from vertical asymmetry and exhibit very good edge-wall roughness. We discuss the results of varying the etching parameters and the detrimental effects that they can have on a device, leading to a diagnostic route that can be taken to identify and eliminate similar issues.
The key to evaluating slow light waveguides is the passive characterization of transmission and group index spectra. Various methods have been reported, most notably resolving the Fabry-Perot fringes of the transmission spectrum20-21 and interferometric techniques.22-25 Here, we describe a direct, broadband measurement technique combining spectral interferometry with Fourier transform analysis.26 Our method stands out for its simplicity and power, as we can characterise a bare photonic crystal with access waveguides, without need for on-chip interference components, and the setup only consists of a Mach-Zehnder interferometer, with no need for moving parts and delay scans.
When characterising photonic crystal cavities, techniques involving internal sources21 or external waveguides directly coupled to the cavity27 impact on the performance of the cavity itself, thereby distorting the measurement. Here, we describe a novel and non-intrusive technique that makes use of a cross-polarised probe beam and is known as resonant scattering (RS), where the probe is coupled out-of plane into the cavity through an objective. The technique was first demonstrated by McCutcheon et al.28 and further developed by Galli et al.29

Use of photonic crystal slow light waveguides and cavities has been widely adopted by the photonics community in many differing applications. Therefore fabrication and characterization of these devices are of great interest. This paper outlines our fabrication technique and two optical characterization methods, namely: interferometric (waveguides) and resonant scattering (cavities).

光子晶体慢光波导和腔体的制备与表征

Slow light has been one of the hot topics in the photonics community in the past decade, generating great interest both from a fundamental point of view ...

科研

工程学

Construction of a High Resolution Microscope with Conventional and Holographic Optical Trapping Capabilities

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular organelles 2,3, as well as for high spatial and temporal resolution readout of their position relative to the center of the trap. The system described herein has one such "traditional" trap operating at 980 nm. It additionally provides a second optical trapping system that uses a commercially available holographic package to simultaneously create and manipulate complex trapping patterns in the field of view of the microscope 4,5 at a wavelength of 1,064 nm. The combination of the two systems allows for the manipulation of multiple refractive objects at the same time while simultaneously conducting high speed and high resolution measurements of motion and force production at nanometer and piconewton scale.

The system described herein employs a traditional optical trap as well as an independent holographic optical trapping line, capable of creating and manipulating multiple traps. This allows for the creation of complex geometric arrangements of refractive particles while also permitting simultaneous high-speed, high-resolution measurements of the activity of biological enzymes.

高分辨率显微镜与常规和全息光学捕获能力建设

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular ...

Sputter Growth and Characterization of Metamagnetic B2-ordered FeRh Epilayers

Chemically ordered alloys are useful in a variety of magnetic nanotechnologies. They are most conveniently prepared at an industrial scale using sputtering techniques. Here we describe a method for preparing epitaxial thin films of B2-ordered FeRh by sputter deposition onto single crystal MgO substrates. Deposition at a slow rate onto a heated substrate allows time for the adatoms to both settle into a lattice with a well-defined epitaxial relationship with the substrate and also to find their proper places in the Fe and Rh sublattices of the B2 structure. The structure is conveniently characterized with X-ray reflectometry and diffraction and can be visualised directly using transmission electron micrograph cross-sections. B2-ordered FeRh exhibits an unusual metamagnetic phase transition: the ground state is antiferromagnetic but the alloy transforms into a ferromagnet on heating with a typical transition temperature of about 380 K. This is accompanied by a 1% volume expansion of the unit cell: isotropic in bulk, but laterally clamped in an epilayer. The presence of the antiferromagnetic ground state and the associated first order phase transition is very sensitive to the correct equiatomic stoichiometry and proper B2 ordering, and so is a convenient means to demonstrate the quality of the layers that can be deposited with this approach. We also give some examples of the various techniques by which the change in phase can be detected.

A method to prepare epitaxial layers of ordered alloys by sputtering is described. The B2-ordered FeRh compound is used as an example, as it displays a metamagnetic transition that depends sensitively on the degree of chemical order and the exact composition of the alloy.

变磁B2有序化的FeRh外延层溅射生​​长和表征

Chemically ordered alloys are useful in a variety of magnetic nanotechnologies. They are most conveniently prepared at an industrial scale using ...

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement is used. Here we operate a Nd:YAG laser at a frequency of 10 Hz at the fundamental wavelength of 1,064 nm. The 14 nsec pulses with anenergy of 190 mJ/pulse are focused to a 50 &#181;m spot size to generate a plasma from optical breakdown or laser ablation in air. The microplasma is imaged onto the entrance slit of a 0.6 m spectrometer, and spectra are recorded using an 1,800 grooves/mm grating an intensified linear diode array and optical multichannel analyzer (OMA) or an ICCD. Of interest are Stark-broadened atomic lines of the hydrogen Balmer series to infer electron density. We also elaborate on temperature measurements from diatomic emission spectra of aluminum monoxide (AlO), carbon (C2), cyanogen (CN), and titanium monoxide (TiO).
The experimental procedures include wavelength and sensitivity calibrations. Analysis of the recorded molecular spectra is accomplished by the fitting of data with tabulated line strengths. Furthermore, Monte-Carlo type simulations are performed to estimate the error margins. Time-resolved measurements are essential for the transient plasma commonly encountered in LIBS.

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown

Time-resolved atomic and diatomic molecular species are measured using LIBS. The spectra are collected at various time delays following the generation of optical breakdown plasma with Nd:YAG laser radiation&#160;and are analyzed to infer electron density and temperature.

测量和原子氢和双原子分子ALO，C分析<sub&gt; 2</sub&gt;，CN和二氧化钛光谱承接激光诱导光学击穿

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement ...

Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator

Most modern radiation therapy devices allow the use of very small fields, either through beamlets in Intensity-Modulated Radiation Therapy (IMRT) or via stereotactic radiotherapy where positioning accuracy allows delivering very high doses per fraction in a small volume of the patient. Dosimetric measurements on medical accelerators are conventionally realized using air-filled ionization chambers. However, in small beams these are subject to nonnegligible perturbation effects. This study focuses on liquid ionization chambers, which offer advantages in terms of spatial resolution and low fluence perturbation. Ion recombination effects are investigated for the microLion detector (PTW) used with the Cyberknife system (Accuray). The method consists of performing a series of water tank measurements at different source-surface distances, and applying corrections to the liquid detector readings based on simultaneous gaseous detector measurements. This approach facilitates isolating the recombination effects arising from the high density of the liquid sensitive medium and obtaining correction factors to apply to the detector readings. The main difficulty resides in achieving a sufficient level of accuracy in the setup to be able to detect small changes in the chamber response.

A growing number of radiation therapy devices offer the advantage of delivering the dose through very small beams to the tumor, allowing for increased conformity and higher doses per fraction. Many different detectors can be used for the dosimetry of these small fields. In the present study, the effect of ion recombination is investigated for a liquid ionization chamber using a stereotactic radiation therapy system.

重组的影响在液体电离室表征用于一个电波加速器的剂量学

Most modern radiation therapy devices allow the use of very small fields, either through beamlets in Intensity-Modulated Radiation Therapy (IMRT) or via ...

Writing and Low-Temperature Characterization of Oxide Nanostructures

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions. Oxide interfaces exhibit a wide range of properties that can be controlled include conduction, piezoelectric behavior, ferromagnetism, superconductivity and nonlinear optical properties. Recently, methods for controlling these properties at extreme nanoscale dimensions have been discovered and developed. Here are described explicit step-by-step procedures for creating LaAlO3/SrTiO3 nanostructures using a reversible conductive atomic force microscopy technique. The processing steps for creating electrical contacts to the LaAlO3/SrTiO3 interface are first described. Conductive nanostructures are created by applying voltages to a conductive atomic force microscope tip and locally switching the LaAlO3/SrTiO3 interface to a conductive state. A versatile nanolithography toolkit has been developed expressly for the purpose of controlling the atomic force microscope (AFM) tip path and voltage. Then, these nanostructures are placed in a cryostat and transport measurements are performed. The procedures described here should be useful to others wishing to conduct research in oxide nanoelectronics.

Oxide nanostructures provide new opportunities for science and technology. The interfacial conductivity between LaAlO3 and SrTiO3 can be controlled with near-atomic precision using a conductive atomic force microscopy technique. The protocol for creating and measuring conductive nanostructures at LaAlO3/SrTiO3 interfaces is demonstrated.

写作和氧化物纳米结构的低温特性

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions.  Oxide ...

Convergent Polishing: A Simple, Rapid, Full Aperture Polishing Process of High Quality Optical Flats &amp; Spheres

Convergent Polishing is a novel polishing system and method for finishing flat and spherical glass optics in which a workpiece, independent of its initial shape (i.e., surface figure), will converge to final surface figure with excellent surface quality under a fixed, unchanging set of polishing parameters in a single polishing iteration. In contrast, conventional full aperture polishing methods require multiple, often long, iterative cycles involving polishing, metrology and process changes to achieve the desired surface figure. The Convergent Polishing process is based on the concept of workpiece-lap height mismatch resulting in pressure differential that decreases with removal and results in the workpiece converging to the shape of the lap. The successful implementation of the Convergent Polishing process is a result of the combination of a number of technologies to remove all sources of non-uniform spatial material removal (except for workpiece-lap mismatch) for surface figure convergence and to reduce the number of rogue particles in the system for low scratch densities and low roughness. The Convergent Polishing process has been demonstrated for the fabrication of both flats and spheres of various shapes, sizes, and aspect ratios on various glass materials. The practical impact is that high quality optical components can be fabricated more rapidly, more repeatedly, with less metrology, and with less labor, resulting in lower unit costs. In this study, the Convergent Polishing protocol is specifically described for fabricating 26.5 cm square fused silica flats from a fine ground surface to a polished ~&#955;/2 surface figure after polishing 4 hr per surface on a 81 cm diameter polisher.

A novel optical polishing process, called &#8220;Convergent Polishing&#8221;, which enables faster, lower cost polishing, is described. Unlike conventional polishing processes, Convergent Polishing allows a glass workpiece to be polished in a single iteration and with high surface quality to its final surface figure without requiring changes to polishing parameters.

收敛抛光：高品质光学平面与球的一种简单，快速，全口径抛光工艺

Convergent Polishing is a novel polishing system and method for finishing flat and spherical glass optics in which a workpiece, independent of its initial ...

Electrochemical Etching and Characterization of Sharp Field Emission Points for Electron Impact Ionization

A new variation of the drop-off method for fabricating field emission points by electrochemically etching tungsten rods in a NaOH solution is described. The results of studies in which the etching current and the molarity of the NaOH solution used in the etching process were varied are presented. The investigation of the geometry of the tips, by imaging them with a scanning electron microscope, and by operating them in field emission mode is also described. The field emission tips produced are intended to be used as an electron beam source for ion production via electron impact ionization of background gas or vapor in Penning trap mass spectrometry applications.

A method for electrochemically etching field emission tips is presented. Etching parameters are characterized and the operation of the tips in field emission mode is investigated.

电化学腐蚀和电子碰撞电离夏普场发射点的表征

A new variation of the drop-off method for fabricating field emission points by electrochemically etching tungsten rods in a NaOH solution is described. ...

Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection

The ability to perform simultaneous resonant excitation and fluorescence detection is important for quantum optical measurements of quantum dots (QDs). Resonant excitation without fluorescence detection &#8211; for example, a differential transmission measurement &#8211; can determine some properties of the emitting system, but does not allow applications or measurements based on the emitted photons. For example, the measurement of photon correlations, observation of the Mollow triplet, and realization of single photon sources all require collection of the fluorescence. Incoherent excitation with fluorescence detection &#8211; for example, above band-gap excitation &#8211; can be used to create single photon sources, but the disturbance of the environment due to the excitation reduces the indistinguishability of the photons. Single photon sources based on QDs will have to be resonantly excited to have high photon indistinguishability, and simultaneous collection of the photons will be necessary to make use of them. We demonstrate a method to resonantly excite a single QD embedded in a planar cavity by coupling the excitation beam into this cavity from the cleaved face of the sample while collecting the fluorescence along the sample&#39;s surface normal direction. By carefully matching the excitation beam to the waveguide mode of the cavity, the excitation light can couple into the cavity and interact with the QD. The scattered photons can couple to the Fabry-Perot mode of the cavity and escape in the surface normal direction. This method allows complete freedom in the detection polarization, but the excitation polarization is restricted by the propagation direction of the excitation beam. The fluorescence from the wetting layer provides a guide to align the collection path with respect to the excitation beam. The orthogonality of the excitation and detection modes enables resonant excitation of a single QD with negligible laser scattering background.

Resonant excitation of a single self-assembled quantum dot can be achieved using an excitation mode orthogonal to the fluorescence collection mode. We demonstrate a method using the waveguide and Fabry-Perot modes of a planar microcavity surrounding the quantum dots. The method allows complete freedom in the detection polarization.

用正交激励和检测方法研究平面腔内铟量子点的共振荧光

The ability to perform simultaneous resonant excitation and fluorescence detection is important for quantum optical measurements of quantum dots (QDs). ...

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.

A protocol for the production of simple structured organic light-emitting diodes (OLEDs) is presented.

真空沉积有机发光二极管的生产与表征

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex ...