EP1565725A2 - Spectrometre d'absorption renforce par un resonateur - Google Patents

Spectrometre d'absorption renforce par un resonateur

Info

Publication number
EP1565725A2
EP1565725A2 EP03795842A EP03795842A EP1565725A2 EP 1565725 A2 EP1565725 A2 EP 1565725A2 EP 03795842 A EP03795842 A EP 03795842A EP 03795842 A EP03795842 A EP 03795842A EP 1565725 A2 EP1565725 A2 EP 1565725A2
Authority
EP
European Patent Office
Prior art keywords
resonator
light beam
detector
sample
measuring light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP03795842A
Other languages
German (de)
English (en)
Inventor
Albert A. Ruth
Sven E. Fiedler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP1565725A2 publication Critical patent/EP1565725A2/fr
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/28—Investigating the spectrum
    • G01J3/42—Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G01N2021/3595—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using FTIR

Definitions

  • the invention relates to a device for determining the absorption in a sample containing
  • the invention further relates to driving a ner to operate such a north direction.
  • a classic method for measuring the wavelength-dependent absorption of a substance is known from classic absorption spectroscopy.
  • the sample is irradiated with white light.
  • White light continuous radiation
  • wavelength continuum ie in the wavelength range under consideration, light is emitted at every wavelength.
  • monochromatic light is understood to mean radiation which is limited to a very narrow wavelength range, ie which consists of only one “color”.
  • absorption spectroscopy the light behind the sample is split into the different wavelengths using a monochromator.
  • the spectrum that arises in this way can be recorded by line or area detectors at the output of the monochromator.
  • the sample does not absorb equally at all wavelengths.
  • the absorption spectrum of the sample can be determined by measuring the radiation, for example with and without a sample or with the aid of a reference beam which leads through a reference medium without absorption.
  • the molecules present in the sample can be identified on the basis of the absorption spectrum recorded, for example by comparison with known molecular spectra. Furthermore, the amount of the molecule present in the sample can be determined. This is done by determining the absorption coefficient, which depends on the concentration and the wavelength-dependent extinction of the substance under consideration.
  • the well-known ner driving is simple and inexpensive, but has only a low sensitivity.
  • DOAS Different Optical Absorption Spectroscopy
  • MPAS multi-pass cells
  • continuum radiation is guided through the sample several times by mirrors, which increases the length of the absorption path. This results in an improved sensitivity.
  • MPAS still suffers from a lack of sensitivity and an unfavorable signal-to-noise ratio due to the losses with each mirror pass.
  • Absorption spectroscopy (CEAS) methods using lasers are known as coherent, monochromatic sources of radiation.
  • the laser light is coupled into an optical resonator.
  • a resonator consists of at least two mirrors with high reflectivity. They are particularly known from laser technology.
  • the coupled light circulates in the resonator and forms so-called modes on the resonator wavelength, i.e. standing waves from minima and maxima. These modes do not develop at other wavelengths.
  • the simplest resonator consists of two parallel planar concave mirrors, the reflecting surfaces of which face each other. But there are also ring resonators from several mirrors. At one of the resonator mirrors, light is coupled out of the resonator and directed to a detector for measurement, where the measurement signal is generated.
  • an absorbent sample is placed in the resonator.
  • a laser pulse from a pulsed laser beam is coupled into the resonator. Due to the reflection losses and losses during decoupling, the light of this laser pulse circulating, ie stored, in the resonator becomes weaker and the signal received at the detector decreases.
  • the temporal signal curve follows an exponential function with the decay time ⁇ 0 if the sample does not absorb. If there is an additional
  • the decay curve of the laser pulse intensity must be reproducible. Correspondingly high demands are made on the individual components that make the process expensive. A particular disadvantage is that the absorption coefficient is only ever measured on one wavelength. In order to measure at other wavelengths, the laser 10. be tunable and the wavelength is passed through, which is time-consuming.
  • Lasers is continuously tuned over the wavelength range around the resonator wavelength.
  • the light is coupled into the resonator in a defined manner and, just like with the CRDS method, can form JVIodes in the resonator
  • the reciprocal temporally integrated transmitted light intensity is proportional to the absorption coefficient of the sample.
  • concentration of a substance in the sample can be determined by simply integrating the signals over time. This method also only works at one wavelength with narrow-band lasers. In addition, regularly occurring fashion jumps in
  • Intracavity spectroscopy in which the measuring light beam is generated by a laser-active medium inside the resonator, only works on one wavelength or is limited to the bandwidth of the laser.
  • broadband, pulsed dye lasers are also used in the "Pulse-stacked cavity ring-down spectroscopy" by E.R. Crosson, P. Haar, G.A. Marcus, H.A. Schwettmann, B.A. Paldus, T.G. Spence and R. N. Zare in Rev. Sei. Instr. 70, 4 used device published in 1999.
  • the method described disperses the recorded laser pulses using a monochromator before they are recorded.
  • the structure described comprises a large number of components and is therefore expensive and, in particular because of the dye laser used, is difficult to handle.
  • A. O'Keefe in Chem. Phys. Lett. 293 (1988) 331 describes a structure in which a pulsed dye laser is used to generate a measuring light beam for CRDS, the signal of which is integrated over time. This structure is also complex because of the used dye laser.
  • Disclosure of the invention It is therefore an object of the invention to provide a device of the type mentioned in the introduction in which measurements can be carried out with high sensitivity over a large spectral range. It is also an object of the invention to provide a device which works more cost-effectively, faster and with less effort in the evaluation.
  • the object is achieved in that spectrometric or interferometric means for spectrally splitting the measuring light beam are provided between the radiation source and the detector and means are provided for generating a signal which represents the amplitude of the measuring light beam independently of the phase.
  • a resonator also increases the sensitivity of an absorption measurement when an incoherent, continuously spectrally radiating radiation source is used.
  • Decomposition of the measuring light beam can then be determined in a particularly simple manner, the absorption coefficient at the desired wavelength.
  • the phase-independent measurement of the amplitude does not necessarily require complex production — a time-varying intensity of the measurement light beam.
  • the device can be made considerably more compact than with broadband dye lasers.
  • the arrangement can also be implemented as a portable device. In contrast to the DOAS applications, a very long absorption path with the associated high sensitivity of the process is realized without large device dimensions.
  • incoherent radiation sources Another and essential advantage of the use of incoherent radiation sources is that broadband radiation can be coupled into the resonator at the same time over wide areas of the visible spectrum. Due to the principle of superposition, the rays do not influence each other. The signals of different wavelengths can can be recorded simultaneously with a monochromator or polychromator. This leads to considerable time savings if measurements have to be carried out at different points in the spectrum.
  • the spectral decomposition enables simple and simultaneous measurement of a spectrum. This simplifies the evaluation and calibration, and reduces the vulnerability of the structure. In addition, the identification of the substances in the sample is made easier and there is the possibility of correcting unwanted background during the measurement. This improves the accuracy of the results.
  • the spectral decomposition means is preferably a dispersing element.
  • a dispersion grating or prism is particularly suitable here.
  • the grating can be configured as a holographic or as an Echelle grating.
  • other means for spectral decomposition can also be used, such as a Fourier transform spectrometer.
  • the spectral decomposition can be in the wavelength range, in the frequency range, in the -wave number range- or on any other suitable scale. be generated. It can scan the spectral range in monochromator mode or in
  • a charge-coupled device (CCD) detector is particularly suitable as a detector. This is characterized by high sensitivity and easy handling. However, any other area detector is also suitable.
  • the radiation source is a xenon high-pressure short-arc lamp.
  • Such lamps work under a high operating pressure of up to 60 bar and emit a spectrum from a little under 200 nm to the near infrared range.
  • the radiance is very high and the emitting light spot of the lamps can be made very small depending on the operating state.
  • Deuterium lamps, simple arc lamps and powerful light bulbs are possible provided they have a sufficient luminance.
  • the resonator mirrors have a high reflectivity in a selected wavelength range and the rest
  • the wavelength range of high reflectivity is the measuring range, while all other light is suppressed to avoid stray light.
  • the reflectivity can be values in the
  • filter means can be provided which limit the wavelengths of the measurement light beam that can be coupled into the resonator to the wavelength range in which the resonator mirrors have a high reflectivity.
  • filters can be interference filters, red and UV filters and combinations of these filters. This reduces the scattered light and prevents higher diffraction orders of the monochromator from falling onto the detector. Wavelengths with high mirror transmission generate a particularly high level of stray light in the monochromator without such filter means.
  • An iris diaphragm is preferably provided to reduce the beam diameter of the measurement light beam in the beam path. With this cover the edge of the
  • Means are preferably provided for imaging the radiation source into the resonator. This can be a lens or a mirror. In one embodiment of the
  • means for focusing the measuring light beam are provided behind the resonator.
  • incoherent light sources can be very divergent. Then the radiation must be focused on the entrance slit of the monochromator or on the detector in order to obtain an optimal signal.
  • the detector can be designed as a line or area detector, with which the signals of the measurement light beam can be recorded on several wavelengths or wavelength ranges. Simultaneous measurement means that more information is recorded at the same time, which can save time, particularly when quantitative analysis of several known substances is carried out. Whole absorption spectra with which molecules can be identified can also be recorded. With reduced measuring times, it is also possible to detect dynamic processes with these detectors.
  • the evaluation of the absorption data obtained which can be composed of the individual spectra of many substances, can be carried out similarly to DO AS, so that the know-how obtained there can be used, at least in part.
  • the sample volume can be evacuated.
  • the arrangement can be used in the atmosphere. Due to the high sensitivity, the detection of weak transitions is also possible.
  • the device is particularly suitable for the detection of atmospheric gases and air pollution, for the observation of flames and combustion processes, liquids and thin layers. It can also be used for long-term measurements of
  • Atmospheric processes photochemical kinetics
  • the measurement of absolute extinction coefficients allows the expansion of databases.
  • Fig.l is a schematic representation of a resonator amplified
  • Fig.2 shows a three absorption spectra of the S j - S 0 transition of azulene
  • the spectrometer 10 comprises a xenon high-pressure short-arc lamp 12, a resonator 14, a monochromator 16 and a detector 18.
  • the lamp 12 essentially consists of a vitreous body in which an anode is located above one
  • Cathode is arranged.
  • the vitreous is filled with xenon.
  • a short arc is formed between the anode and cathode when a voltage is applied.
  • the operating pressure can then rise to around 60 bar.
  • the shortbow emits radiation in the Wavelength range between approximately 200 ⁇ m and 1200 nm.
  • the arc is up to 150 micrometers small. As a result, it has good imaging properties.
  • the lamp 12 also has a high spectral luminance, ie a high output per radiation area, solid angle and wavelength unit. It can assume values in the range of 10-20 W / (cm 2 sr nm).
  • the divergent radiation represented by the marginal rays 20 is focused in the center 22 of the resonator 14.
  • an achromatic lens 24 is used in the present exemplary embodiment.
  • Lamp in the resonator about 3 to 4 mm in size.
  • a mirror can of course also be used instead of a lens.
  • UV filter 26 An ultraviolet filter (UV filter) 26 is arranged between the lamp 12 and the lens 24.
  • the filter 26 only transmits light above 335 nm and prevents the second and higher diffraction orders of the UV filter in the monochromator 16 from falsifying the measurement data when working in a range around 610 nm.
  • An interference filter 28 is also provided in front of the resonator 14.
  • Interference filter only allows radiation in the range of about 40 n around the measuring wavelength (corresponding to a half-value width of 40 nm). This is part of the wavelength range for which the resonator mirrors 30 and 32 of the resonator 14 are highly reflective. All other wavelengths are suppressed. Wavelengths at which the mirrors have a high transmission produce a high level of stray light in the monochromator. Using the interference filter 28 reduces the level of stray light. Depending on the wavelength range in which the measurement is carried out, an interference filter with a different transmission maximum can be used.
  • a first iris diaphragm 34 is provided between the resonator 14 and the interference filter 28.
  • a second iris diaphragm 36 is provided behind the resonator 14. The edge of the beam path is cut off with the iris diaphragms 34 and 36. This will make the order the oscillating transverse modes of the resonator are reduced and the optical quality of the beam is improved.
  • the resonator 14 comprises two mirrors 30 and 32. These are mirrored for a selected wavelength range of approximately 60 nm around the central wavelength of 610 nm in such a way that they have a reflectivity of 99.99%. This means that 99.99% of the incident radiation is reflected and 0.01% of the radiation - if other losses are not taken into account - is transmitted.
  • the mirrors are designed as two dielectric plan Kohkav mirrors. They are 45 cm apart and their position can be adjusted. The resonator is in an evacuable
  • the volume 38 can be evacuated via a first valve 40 with a pump. Furthermore, a second valve 42 is provided, via which a gaseous sample can be let into the volume 38.
  • cuvettes or the like with a sample can also be introduced into the resonator. Then it is possible to provide the cuvettes themselves instead of providing their own resonator mirrors so that their sides form the resonator.
  • a red filter 44 is provided behind the aperture 36. This serves to suppress
  • Monochromator 16 shown.
  • the monochromator generates a spectrum of the transmitted radiation on the detector 18, which is located in the exit plane of the monochromator 16.
  • the monochromator has an entrance slit of 0.2 mm width, a focal length of 25 cm and a grating with 600 lines / mm. This results in a resolution of 1.2 nm in the considered wavelength range at 610 nm.
  • the wavelength calibration is carried out by means of a neon hollow cathode lamp 56.
  • the radiation from the lamp 56 can be calibrated via a mirror 52 and a lens 54 are mapped onto the entrance slit of the monochromator.
  • an aperture 58 is provided to limit the beam path.
  • the neon hollow cathode lamp 56 emits a large number of narrow-band, very well-known lines over a large wavelength range and is therefore well suited for calibration.
  • a photodiode array is used as the detector, which is connected to a MicroChannel plate by glass fibers
  • MCP image intensifier
  • FIG. 2 shows an example 60 for an absorption spectrum of azulene and in FIG. 3 an example 62 for a very weak absorption of gaseous oxygen.
  • spectra are shown that were recorded using CRDS and CRDS with a jet.
  • the spectrum 64 for azulene or 66 for oxygen recorded with incoherent light source is broadened compared to the nozzle flow CRDS spectrum 68 or 70, since the effective temperature in the nozzle jet is considerably lower than room temperature. Pressure and Doppler broadening mechanisms therefore no longer play a role. It can be seen that the spectra recorded with CRDS show a course comparable to an offset, like the spectra recorded with incoherent light source.
  • the arrangement described can be used for trace gas analysis
  • the arrangement is used as a detector for the
  • High pressure liquid chromatography used.
  • the molecules separated on the chromatographic column are examined in a cell as in conventional absorption spectroscopy.
  • Conventional absorption spectroscopy uses an arrangement with a lamp, a cell, a monochromator and a suitable detector.
  • the arrangement according to the present exemplary embodiment additionally uses an optical resonator or built around the cuvette mirrored cell walls. The previous components do not need to be replaced.
  • a conventional absorption spectrometer can therefore be used with only low conversion costs.

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  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Biochemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Spectrometry And Color Measurement (AREA)

Abstract

L'invention concerne un dispositif (10) utilisé pour déterminer l'absorption d'un échantillon, qui comprend une source de rayonnement incohérente (12) servant à produire un rayon lumineux de mesure (20), un résonateur (14) comportant au moins deux miroirs (30, 32), dans lequel peut être injecté le rayon lumineux de mesure, un volume à échantillon (38) destiné à recevoir un échantillon soumis à l'absorption à l'intérieur du résonateur (14) et un détecteur (18) destiné à capter le rayonnement pouvant sortir du résonateur (14). Ce dispositif se caractérise en ce qu'entre la source de rayonnement (12) et le détecteur (18) se trouvent des moyens spectrométriques ou interférométriques (16) servant à la décomposition spectrale du rayon lumineux de mesure, ainsi que des moyens générant un signal qui représente l'amplitude du rayon lumineux de mesure indépendamment de la phase.
EP03795842A 2002-11-25 2003-11-24 Spectrometre d'absorption renforce par un resonateur Ceased EP1565725A2 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10255022 2002-11-25
DE10255022A DE10255022A1 (de) 2002-11-25 2002-11-25 Resonatorverstärktes Absorptions-Spektrometer
PCT/EP2003/013174 WO2004048907A2 (fr) 2002-11-25 2003-11-24 Spectrometre d'absorption renforce par un resonateur

Publications (1)

Publication Number Publication Date
EP1565725A2 true EP1565725A2 (fr) 2005-08-24

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Family Applications (1)

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EP03795842A Ceased EP1565725A2 (fr) 2002-11-25 2003-11-24 Spectrometre d'absorption renforce par un resonateur

Country Status (5)

Country Link
US (1) US7755767B2 (fr)
EP (1) EP1565725A2 (fr)
AU (1) AU2003298140A1 (fr)
DE (1) DE10255022A1 (fr)
WO (1) WO2004048907A2 (fr)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0624148D0 (en) * 2006-12-02 2007-01-10 Univ Teesside Detection method
DE102007042172A1 (de) 2007-09-05 2009-03-12 Fabiola Basan Verfahren und optische Anordnung zur breitbandigen Messung geringer optischer Verluste
WO2011134111A1 (fr) * 2010-04-30 2011-11-03 Siemens Aktiengesellschaft Spectromètre optique et procédé pour augmenter l'intensité de signal en spectroscopie optique
DE102010030549B4 (de) 2010-06-25 2016-04-28 Siemens Aktiengesellschaft Nichtdispersiver Gasanalysator
DE102012106867B4 (de) * 2012-07-27 2016-10-13 Universität Hamburg Vorrichtung und Verfahren zur resonator-verstärkten optischen Absorptionsmessung an Proben mit kleinem Absorptionswirkungsquerschnitt
US9052232B2 (en) * 2012-12-19 2015-06-09 Thermo Scientific Portable Analytical Instruments Inc. Spheroid sample cell for spectrometer
DE102015100395B4 (de) 2014-02-03 2020-06-18 Bürkert Werke GmbH Spektrometer und Fluid-Analysesystem
WO2017044303A1 (fr) * 2015-09-11 2017-03-16 Ocean Optics, Inc. Filtre de suppression de lumière au xénon pour spectrométrie
US9709491B1 (en) * 2016-03-28 2017-07-18 The United States Of America System and method for measuring aerosol or trace species
US10705407B2 (en) 2017-05-08 2020-07-07 Analog Photonics LLC Speckle reduction in photonic phased arrays
US11513224B2 (en) 2018-05-03 2022-11-29 Analog Photonics LLC Multi-static coherent LiDAR
US11525915B2 (en) 2018-05-03 2022-12-13 Analog Photonics LLC Multi-static coherent LiDAR
EP3650833A1 (fr) * 2018-11-09 2020-05-13 Technische Universität München Résonateur optique multicolore pour procédés d'imagerie
RU188171U1 (ru) * 2018-12-25 2019-04-02 Федеральное государственное автономное образовательное учреждение высшего образования "Национальный исследовательский Томский государственный университет" (ТГУ, НИ ТГУ) Радиоволновой спектрометр
KR20210141512A (ko) * 2019-03-20 2021-11-23 아날로그 포토닉스, 엘엘씨 멀티-스태틱 간섭성 라이더

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3524066A (en) * 1966-08-22 1970-08-11 Monsanto Co Fluid measurement system having sample chamber with opposed reflecting members for causing multiple reflections
GB2181536A (en) * 1985-08-09 1987-04-23 Plessey Co Plc Wavelength scanning optical sensor
DE3813152A1 (de) * 1988-04-20 1989-11-02 Felten & Guilleaume Energie Einrichtung mit einem optischen gassensor zur dichtemessung und -ueberwachung von gasen
US5528040A (en) * 1994-11-07 1996-06-18 Trustees Of Princeton University Ring-down cavity spectroscopy cell using continuous wave excitation for trace species detection
DE19528919A1 (de) 1995-08-07 1997-02-20 Microparts Gmbh Mikrostrukturiertes Infrarot-Absorptionsphotometer
US5742054A (en) * 1995-09-01 1998-04-21 Innovative Lasers Corporation Ultra-sensitive detection of contaminants in corrosive gas via intracavity laser spectroscopy (ILS)
US5986768A (en) * 1997-10-31 1999-11-16 The United States Of America, As Represented By The Secretary Of Commerce Intra-cavity total reflection for high sensitivity measurement of optical properties
JP2000206035A (ja) * 1999-01-19 2000-07-28 Anritsu Corp ガス検出装置
US6094267A (en) * 1999-04-21 2000-07-25 The Board Of Trustees Of The Leland Stanford Jr. University Optical heterodyne detection for cavity ring-down spectroscopy
WO2002004903A1 (fr) * 2000-07-12 2002-01-17 Macquarie Research Ltd Detection optique heterodyne en spectroscopie optique de ringdown de cavite
US6839140B1 (en) 2002-07-03 2005-01-04 Los Gatos Research Cavity-enhanced liquid absorption spectroscopy
US7695680B2 (en) * 2003-03-19 2010-04-13 The Trustees Of Boston University Resonant cavity biosensor

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
DASGUPTA P K ET AL: "Optical cells with partially reflecting windows as nonlinear absorbance amplifiers", ANALYTICAL CHEMISTRY, AMERICAN CHEMICAL SOCIETY, US, vol. 59, 1 January 1987 (1987-01-01), pages 783 - 786, XP003025398, ISSN: 0003-2700, DOI: DOI:10.1021/AC00132A022 *
DASGUPTA P.K. ET AL: "Optical cells with partially reflecting windows as nonlinear absorbance amplifiers", AMERICAN CHEMICAL SOCIETY, vol. 59, 1987, pages 783 - 786, XP003025398
GHERMAN T ET AL: "Mode-locked cavity-enhanced absorption spectroscopy", QUANTUM ELECTRONICS CONFERENCE,, vol. 10, no. 19, 23 September 2002 (2002-09-23), pages 1033 - 1042, XP003025397 *
GHERMAN T. ET AL: "Mode-locked cavity-enhanced absorption spectroscopy", QUANTUM ELECTRONICS CONFERENCE, vol. 10, no. 19, 20 September 2002 (2002-09-20), pages 1033 - 1042, XP003025397

Also Published As

Publication number Publication date
AU2003298140A1 (en) 2004-06-18
AU2003298140A8 (en) 2004-06-18
WO2004048907A2 (fr) 2004-06-10
US20060072117A1 (en) 2006-04-06
WO2004048907A3 (fr) 2004-08-26
US7755767B2 (en) 2010-07-13
DE10255022A1 (de) 2004-06-17

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