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公开(公告)号：US5912740A
公开(公告)日：1999-06-15
申请号：US879975
申请日：1997-06-20
摘要： Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS).
摘要翻译： 用于光谱的环形谐振腔允许减少对光源的光学反馈，并提供关于s和p偏振光与样本的相互作用的信息。 激光光源被锁定到单腔模式。 可以使用腔内声光调制器将光耦合到腔中。 腔体几何形状特别适用于腔内环形光谱（CRDS）。
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公开(公告)号：US5815277A
公开(公告)日：1998-09-29
申请号：US949242
申请日：1997-10-10
摘要： Light is coupled into a cavity ring down spectroscopy (CRDS) resonant cavity using an acousto-optic modulator. The AOM allows in-coupling efficiencies in excess of 40%, which is two to three orders of magnitude higher than in conventional systems using a cavity mirror for in-coupling. The AOM shutoff time is shorter than the roundtrip time of the cavity. The higher light intensities lead to a reduction in shot noise, and allow the use of relatively insensitive but fast-responding detectors such as photovoltaic detectors. Other deflection devices such as electro-optic modulators or elements used in conventional Q-switching may be used instead of the AOM. The method is particularly useful in the mid-infrared, far-infrared, and ultraviolet wavelength ranges, for which moderately reflecting input mirrors are not widely available.
摘要翻译： 使用声光调制器将光耦合到空腔环形光谱（CRDS）谐振腔中。 AOM允许超过40％的耦合效率，这比使用用于耦合的腔镜的常规系统高两到三个数量级。 AOM关闭时间比空腔的往返时间短。 较高的光强度导致散粒噪声的降低，并且允许使用相对不敏感但快速响应的检测器，例如光伏检测器。 可以使用诸如电光调制器或常规Q开关中使用的元件的其它偏转装置来代替AOM。 该方法在中红外线，远红外线和紫外线波长范围内特别有用，对于中等反射输入反射镜不能广泛使用。
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3.发明授权
公开(公告)号：US5903358A
公开(公告)日：1999-05-11
申请号：US949241
申请日：1997-10-10
摘要： A cavity ring down spectroscopy (CRDS) system uses a free-running continuous wave (c.w.) diode laser stabilized by frequency-shifted optical feedback in the presence of strong reflections from a high-finesse Fabry-Perot resonator. The frequency-shifted feedback stabilization eliminates the need for tightly controlling the relative positions of the laser and resonator. Non-frequency-shifted feedback is used for linewidth broadening. An acousto-optic modulator placed between the diode laser output and the resonator input frequency-shifts light reflected by the resonator input, causing the laser to cycle in phase with a period equal to the inverse of the frequency-shift. The laser diode linewidth can be stabilized from several MHz for high resolution spectroscopy of species at low pressures, to several hundred MHz for lower resolution spectroscopy of species at atmospheric pressures.
摘要翻译： 空腔环形光谱（CRDS）系统使用在高精度Fabry-Perot谐振器存在强反射的情况下通过频移光学反馈稳定的自由运行连续波（c.w.）二极管激光器。 频移反馈稳定消除了对激光器和谐振器的相对位置的紧密控制的需要。 非频移反馈用于线宽展宽。 放置在二极管激光器输出和谐振器输入之间的声光调制器频移由谐振器输入反射的光，使得激光器以等于频移倒数的周期相位循环。 激光二极管线宽可以从几MHz稳定，用于低压物种的高分辨率光谱，到几百MHz，用于在大气压下物种的较低分辨光谱。
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公开(公告)号：US6084682A
公开(公告)日：2000-07-04
申请号：US61080
申请日：1998-04-15
CPC分类号： G01N21/39 , G01N2021/391
摘要： Distinct locking and sampling light beams are used in a cavity ring-down spectroscopy (CRDS) system to perform multiple ring-down measurements while the laser and ring-down cavity are continuously locked. The sampling and locking light beams have different frequencies, to ensure that the sampling and locking light are decoupled within the cavity. Preferably, the ring-down cavity is ring-shaped, the sampling light is s-polarized, and the locking light is p-polarized. Transmitted sampling light is used for ring-down measurements, while reflected locking light is used for locking in a Pound-Drever scheme.
摘要翻译： 不同的锁定和采样光束在空腔衰减光谱（CRDS）系统中被使用，以在激光和衰减腔被连续锁定的同时进行多次衰减测量。 采样和锁定光束具有不同的频率，以确保采样和锁定光在腔内解耦。 优选地，环形腔是环形的，采样光是s偏振的，并且锁定光是p偏振的。 发射采样灯用于衰减测量，而反射锁定灯用于锁定Pound-Drever方案。
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公开(公告)号：US06233052B1
公开(公告)日：2001-05-15
申请号：US09273195
申请日：1999-03-19
IPC分类号： G01N2100
CPC分类号： G01N21/39
摘要： An analog detection system for determining a ring-down rate or decay rate 1/&tgr; of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.
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公开(公告)号：US6094267A
公开(公告)日：2000-07-25
申请号：US295213
申请日：1999-04-21
IPC分类号： G01J3/26 , G01J3/30 , G01J3/42 , G01J3/447 , G01J9/04 , G01N21/03 , G01N21/21 , G01N21/27 , G01N21/39 , H01S3/00 , G01B9/02
摘要： A cavity ring-down system for performing cavity ring-down spectroscopy (CRDS) using optical heterodyne detection of a ring-down wave E.sub.RD during a ring-down phase or a ring-up wave E.sub.RU during a ring up phase. The system sends a local oscillator wave E.sub.LO and a signal wave E.sub.SIGNAL to the cavity, preferably a ring resonator, and derives an interference signal from the combined local oscillator wave E.sub.LO and the ring-down wave E.sub.RD (or ring-up wave E.sub.RU). The local oscillator wave E.sub.LO has a first polarization and the ring-down wave E.sub.RD has a second polarization different from the first polarization. The system has a combining arrangement for combining or overlapping local oscillator wave E.sub.LO and the ring-down wave E.sub.RD at a photodetector, which receives the interference signal and generates a heterodyne current I.sub.H therefrom. Frequency and phase differences between the waves are adjustable.
摘要翻译： 一种空穴衰减系统，用于在振铃阶段期间使用环形衰减波ERR的环外波检测来执行空腔衰减光谱（CRDS）。 该系统将本地振荡器波ELO和信号波ESIGNAL发送到腔，优选地是环形谐振器，并且从组合的本地振荡器波ELO和衰减波ERD（或振铃波ERU）导出干扰信号。 本地振荡器波ELO具有第一极化，并且降波波ERD具有与第一极化不同的第二极化。 该系统具有用于组合或重叠本地振荡器波ELO和在光电检测器处的衰减波ERD的组合布置，其接收干扰信号并从其产生外差电流IH。 波之间的频率和相位差可调。
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公开(公告)号：US06532071B2
公开(公告)日：2003-03-11
申请号：US09755253
申请日：2001-01-04
IPC分类号： G01N2117
CPC分类号： G01N21/39
摘要： An analog detection system for determining a ring-down rate or decay rate 1/&tgr; of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.
摘要翻译： 一种模拟检测系统，用于确定在衰落阶段期间从寿命或衰落腔中发出的指数衰减衰减波束的衰减速率或衰减速率1 /τ。 或者，模拟检测系统确定在振铃阶段期间从空腔发出的指数增长的光束的累积速率。 模拟系统可用于连续波腔衰减光谱（CW CRDS）和脉冲CRDS（P CRDS）布置，利用任何类型的环形腔包括环形腔和线性腔。
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公开(公告)号：US06466322B1
公开(公告)日：2002-10-15
申请号：US09470903
申请日：1999-12-23
申请人： Barbara A. Paldus , Richard N. Zare
发明人： Barbara A. Paldus , Richard N. Zare
IPC分类号： G01N2161
CPC分类号： G01N21/39
摘要： An ring-down spectroscopy instrument comprising a ring-down cavity (RDC) and CW light source (CWLS). The CWLS produces light having components with different polarizations. The ring-down cavity is optically isolated from the light source so that light reflected from the cavity is precluded from perturbing the light source. A frequency shifter shifts a mean frequency of the first component of input light with respect to a mean frequency of the second component of input light by a frequency shift &Dgr;&ngr;. A first detector measures a signal beam with the a polarization. A second detector measures a tracking beam having a second polarization. The frequency shift &Dgr;&ngr; is equal to a difference between a resonant frequency of a first cavity mode with the first polarization and a resonant frequency of a second cavity mode having the second polarization. A threshold detector delivers a trigger pulse to the frequency shifter when an intensity of the signal beam reaches a predetermined value. The trigger pulse causes the frequency shifter to temporarily change the frequency shift &Dgr;&ngr;, thereby temporarily decoupling the first component of input light from the ring-down cavity. An embodiment of the invention includes a ring down spectroscopy method. Radiation coupled into a ring-down cavity is swept in frequency by to excite one or more resonant modes of the cavity. When a fundamental mode of the cavity reaches a predetermined threshold value a digitizer produces a ring-down decay curve. An absorption spectrum is determined by extrapolating a decay constant from a logarithm of the decay curve.
摘要翻译： 一种振铃光谱仪，包括一个环形腔（RDC）和CW光源（CWLS）。 CWLS产生具有不同偏振分量的光。 环形腔与光源光学隔离，使得从空腔反射的光不被扰乱光源。 频移器将输入光的第一分量的平均频率相对于输入光的第二分量的平均频率移位频移DELTA＆lt; ngr。 第一检测器测量具有偏振的信号光束。 第二检测器测量具有第二偏振的跟踪光束。 频移DELTA＆ngr; 等于具有第一极化的第一腔模式的谐振频率和具有第二极化的第二腔模式的谐振频率之间的差。 当信号光束的强度达到预定值时，阈值检测器将触发脉冲传送到移频器。 触发脉冲使得移频器暂时改变频移DELTA＆ngr，从而暂时将输入光的第一分量与衰减腔分离。 本发明的实施例包括环形光谱法。 通过激发耦合到环形腔中的一个或多个谐振模式的频率来扫描耦合到环形腔中的辐射。 当空腔的基本模式达到预定阈值时，数字转换器产生衰减衰减曲线。 通过从衰减曲线的对数外推衰减常数来确定吸收光谱。
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公开(公告)号：US06452680B1
公开(公告)日：2002-09-17
申请号：US09497309
申请日：2000-02-03
IPC分类号： G01N2100
摘要： Method and system for cavity ring down spectroscopic analysis of non-cavity-filling sample. An interface of a sample (gas, liquid, thin film, bulk solid, etc.) is positioned at a Brewster angle relative to a p-wave polarized light beam propagating in an optical cavity so that substantially no light beam energy is lost by reflection at the interface. The light beam cycles one or more times in the cavity for each of a sequence of selected wavelengths, is extracted from the cavity, and is analyzed to determine an absorption spectrum for the sample. The cavity, except for the sample region may be filled with a solid, optionally dielectrically active and optionally having an electrical field applied thereto to vary the solid's refractive index according to the light beam wavelength used.
摘要翻译： 空腔填充样品的腔环下光谱分析方法与系统。 样品（气体，液体，薄膜，体积固体等）的界面相对于在光腔中传播的p波偏振光束位于布鲁斯特角，使得基本上没有光束能量被反射损失 在界面。 对于所选波长序列中的每一个，光束在空腔中循环一次或多次，从空腔中提取，并且被分析以确定样品的吸收光谱。 除了样品区域之外的空腔可以填充固体，任选地介电活性并且任选地具有施加到其上的电场以根据所使用的光束波长改变固体的折射率。
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公开(公告)号：US06959023B1
公开(公告)日：2005-10-25
申请号：US10231647
申请日：2002-08-29
CPC分类号： H01S5/141 , H01S5/0265 , H01S5/142
摘要： A tunable laser and laser tuning method based on the use of a tunable etalon in reflection as a mirror within a laser cavity. The laser emission wavelength is not necessarily at a wavelength of peak etalon reflectivity. A preferred embodiment makes use of a microelectromechanical etalon to tune an external cavity semiconductor laser.
摘要翻译： 基于在激光腔内作为反射镜使用可调标准具的可调谐激光和激光调谐方法。 激光发射波长不一定在标准具有峰值反射率的波长。 优选的实施例利用微机电标准具来调谐外腔半导体激光器。
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