Connecticut College, New London, Connecticut usa general Physics Institute, Russian Academy of Sciences, Moscow, Russia
ASSYST - ADVANCED LASER SENSOR SYSTEMS FOR LEADING EDGE MANUFACTURING
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E9.ASSYST - ADVANCED LASER SENSOR SYSTEMS FOR LEADING EDGE MANUFACTURING V.Hopfe1, P.A. Martin2, R.J.Holdsworth3, D.W.Sheel4, P.Kaspersen5, P.K.de Bokx6, P.Mackrodt7, M.E.Pemble8, A.Linton9, F.Petzold10 1 Fraunhofer Institute for Material and Beam Technology, Winterbergstrasse 28, D-01277 Dresden, Germany 2University of Manchester Institute of Science and Technology (UMIST), Department of Chemical Engineering, PO Box 88. Manchester M60 1QD. UK 3 TDL Sensors Ltd., UVL, Sackville Street, ManchesterM60 1QD, UK 4 CVD Technologies Ltd., Cockcroft Building, Salford Campus, Salford, M5 4WT, UK 5 Norsk Elektro Optikk A/S, Solnheimveien 62A, PO Box 384, N-1471 Skaarer, Norway 6 Philips CFT, Materials Analysis Department, Prof. Holstlaan 4/WB 72, 5656 AA Eindhoven, Netherlands 7 Physikalisch Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig, Germany 8 University of Salford, Materials Research Institute, Salford M5 4WT, UK 9 PDZ Europa Ltd.,Langdale House Gadbrook Business Centre, Rudheath, Northwich, Cheshire, CW9 7TN, UK 10 Intega GmbH, Bergener Ring 51, D-01458 Ottendorf-Okrilla, Germany ASSYST is an EU Framework 5 project which targets the development of novel sensors to achieve next generation product quality and process control levels. Optical sensors based on tunable diode lasers in the near-infrared have clear advantages in many applications where, for instance, non-invasive, in-situ technique is required. It can also be the only industrial choice where reactive or corrosive gases are involved. Recent rapid developments in technologies critical to NIR-Diode Laser spectroscopy, mainly in the telecoms industry, and the emergence of potential new application areas have catalysed this project and hold out the potential for a step-change in spectroscopic monitoring. Five promising applications have been first selected. The partnership is well-balanced between equipment and technology developers and end users many having a large share in the market they operate in. 4 countries (including less favoured) and 5 innovative expanding SMEs are included. Details of the project will be presented. E10.DIODE-LASER-BASED DOPPLER-FREE SPECTROSCOPY OF RARE EARTH ATOMS IN NIR AND NUV REGION Hyunmin Park, Duck-hee Kwon, Yongho Cha, Jaemin Han and Yongjoo Rhee Laboratory for Quantum Optics, Korea Atomic Energy Research Institute P. O. Box 105, Yuseong, Daejeon, 305-600, Korea For the last few decades, the atomic spectroscopic data on rare earth elements has been widely investigated experimentally and theoretically because they are very important in industrial and medical applications and they provide valuable information regarding the fundamental properties of the nucleus and the atom. However, in the NUV and NIR region, only a limited number of results have been reported due to the lack of tunable laser sources in the regions. Recently, the tunable diode lasers have been widely used in high resolution spectroscopy in NUV and NIR range because of their narrow linewidth, wide tunability and compactness. In this work, we conducted a high-resolution spectroscopy of rare-earth elements such as La, Sm, Yb, Er, and Dy in the 397-400nm and 635-690nm region by using a single-mode tunable diode laser. The oscillators of the diode laser are Littrow-type (UV region) and Littman-type(IR region) which enable the lasers to be operated in a single longitudinal mode and to be continuously tunable with minimum mode hops. The power of the diode laser was normally about 5mW and especially it was amplified to more than 500mW by using master-oscillator power-amplifier(MOPA) configurations in the wavelength region of 670-690nm. For atomic sources of rare earth elements, a hollow-cathode-lamp(HCL) was used for elements(La, Er, Dy) with a high melting point and a long vapor cell for elements(Yb, Sm) with a low melting point, respectively. To obtain the Doppler-free spectra on the transition lines of above mentioned elements, we used a saturation absorption spectroscopy. Moreover, we adopted a polarization intermodulated excitation method (POLINEX) in order to decrease the velocity-changing-collision(VCC) effects which produce a Gaussian pedestal on the Lorentzian shape of a narrow spectral line. As experimental results, isotope shifts and hyperfine structures of many transition lines of rare earth elements were newly measured with a good resolution and were analyzed by using several methods. We expect that our results will be helpful for a theoretical consideration, such as multi-configuration Dirac-Fork calculation of the large mass atoms. E11.Cavity Enhanced and Polarisation Studies using Tunable Diode Lasers G. Hancock, A. Hutchinson, R. Peverall, G. Ritchie Physical and Theoretical Chemistry Laboratory, The University of Oxford, South Parks Road, Oxford, OX1 3QZ A simple fibre based cavity enhanced diode laser spectrometer is described for the accurate measurement of isotope ratios in carbon dioxide. Radiation from a fibre pigtailed distributed feedback diode laser is coupled into a vacuum vessel containing a high finesse optical cavity. The cavity provides an effective optical pathlength of several km. The technique of cavity enhanced absorption spectroscopy is used to record the spectrum of a few Torr of CO2 around 1.6 m where there are adjacent 13CO2 and 12CO2 lines of similar strength for the naturally occurring 12C/13C ratio. The sensitivity of the technique allows the ratio to be measured with a precision that approaches that of the mass spectrometric gold standard, within a relatively short time. Tunable diode laser systems have also been developed for the non-invasive interrogation of technical plasmas. In particular, Doppler free polarisation spectroscopy is demonstrated in a neon plasma, using single mode Fabry-Perot devices between 635 nm and 660 nm to probe excited states of neon. Spectral line widths as low as 50 MHz are observed for those transitions from metastable states (i.e. those transitions involving states with a long lifetime). The suitability of this technique for the elucidation of magnetic and electric fields within the plasma is investigated. E12.INFLUENCE OF TEMPERATURE ON THE COLLISION BROADENING OF IR SPECTRAL LINES OF CO2 MOLECULES S.N. Andreev, V.N. Ochkin, S.Yu. Savinov P.N.Lebedev Physical Institute, Leninskii prosp. 53, 119991 Moscow, Russia CO2 gas transmission at 4.5μ band (vibrational-rotational radiating transitions  ) have been measured by means of tunable diode laser spectroscopy technique. On this base the IR linewidths of CO2 molecules were obtained in wide field of a gas temperature (T) and rotational quantum numbers (J). It has been found that there are no existing semiclassical models of pressure broadened linewidths to describe satisfactorily our and other published experimental results.
A new cutoff-free semiclassical model of pressure broadening of rotation-vibration spectra in gases was provided. It corresponds to all experimental results quite well. The model takes into account: trajectory bend of moving particles by intermolecular forces, increasing of optical cross section for molecules with low relative energy of translation motion due to orbiting collisions. I Figure 1. Experimental and calculated (using the ATC approximation and the model proposed in this paper) dependences of the collision half-widths of CO2 spectral lines on Ji at T=170K and p=77,6Torr t takes not so much computing time to calculate the impact broadened linewidths (only slightly more time than calculations by Anderson-Tsao-Curnutte theory). It enables us to compute the shape of IR spectral lines with correct averaging over a distribution of relative velocities. The important role of particles collisions with low relative energy of translation motion E (E/ < 0.8, where is constant of Lennard-Jones itermolecular potential) even under room temperature has been shown. This role is increased essentially at lower temperature. In Figure 1 experimental dependence of the collision half-widths of CO2 spectral lines on Ji at T=170K and p=77,6Torr is represented. The calculated results also displayed. One can see that discussed above model quite sufficiently fits experimental data. It has been found that commonly applied calculation scheme of average linewidths over a Maxwell-Boltzmann distribution of relative velocities can lead to systematic errors. The above features make our results attractive for its usage for determinations of exact linewidths in molecular infrared spectra. The work was partially supported by Federal programs “Integration” (project A0133), “Optics, laser physics”, Sc.Progr. of RAS ”Optical spectroscopy”, grant of the RFBR 02-02-81008, NATO research grant JSTC.CLG.978204. Directory: 2003 2003 -> Tr-41. 4-03-05-024 Telecommunications 2003 -> Review of some tsunamis in canada 2003 -> The skill of multi-model seasonal forecasts of the wintertime North Atlantic Oscillation 2003 -> 2930 Kerry Forest Parkway 2003 -> Canadian Interuniversity Sport (cis) Athletes of the Week 2003 -> Senior Airman Jason Plite Hometown 2003 -> Technical announcements: My apologies for the comparison pages; they were 2003 -> Pool Play Round 1 9: 20: 00 am 2003 -> 2004 Division II men's Golf Championships Final Round Results deland, fla 2003 -> Go Figure Edited by Kostya Kennedy and Mark Bechtel 645 Passing yards, an ncaa division II record, by University of Indianapolis quarterback Matt Kohn, in a 59-52 victory over Michigan Tech Download 1.65 Mb. Share with your friends:
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