35 research outputs found

    Femtosecond laser spectroscopy for Exploration of Space

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    Space agencies around the world have the exploration of solar system bodies in the focus of their activities for decades already. The search for traces of life and to a better understanding of the geology of planets, moons and asteroids motivates these explorations. Our (DLR institute for Optical Sensor Systems (DLR-OS)) contribution to this topic is the development of spectroscopic sensors for material identification. DLR-OS is developing a wide range of spectroscopic sensors that reach from passive infrared spectrometers for remote sensing employed on orbiters to active laser spectroscopies such as NIR spectroscopy, Raman spectroscopy or Laser-Induced Breakdown Spectroscopy that are employed on robotic lander missions. Space, weight and power restrictions as well as robustness against harsh environmental conditions are inherent prerequisites for space missions and lead to specific design solutions for these instruments. Driven by emerging technology of space ready shortpulsed (femtosecond) lasers we are introducing the new topic of time domain spectroscopies to space exploration. In this work, we present our first results on coherent phonon and THz time domain spectroscopies on space relevant minerals.XVI Photonics Workshop : Book of abstracts; March 12-15, 2023; Kopaonik, Serbi

    High contrast D1_{1} line electromagnetically induced transparency in nanometric-thin rubidium vapor cell

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    Electromagnetically induced transparency (EIT) on atomic D1_{1} line of rubidium is studied using a nanometric-thin cell with atomic vapor column length in the range of L= 400 - 800 nm. It is shown that the reduction of the cell thickness by 4 orders as compared with an ordinary cm-size cell still allows to form an EIT resonance for L=Ī»L= \lambda (Ī»=794\lambda =794 nm) with the contrast of up to 40%. Remarkable distinctions of EIT formation in nanometric-thin and ordinary cells are demonstrated. Despite the Dicke effect of strong spectral narrowing and increase of the absorption for L=L= Ī»/2\lambda /2, EIT resonance is observed both in the absorption and the fluorescence spectra for relatively low intensity of the coupling laser. Well resolved splitting of the EIT resonance in moderate magnetic field for L=L= Ī»\lambda can be used for magnetometry with nanometric spatial resolution. The presented theoretical model well describes the observed results.Comment: Submitted to Applied Physics B: Lasers and Optics, 9 pages, 10 figure

    Ultrafast High-Field THz beamline at X-ray FEL

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    THz sources at FLASH utilize spent electron beam from a soft X-ray FEL to generate very intense (up to 150ĀµJ), tunable frequency (1-300THz) and ultrafast narrowband (~10%) THz pulses, which are naturally synchronized to soft X-ray pulses [1]. This unique combination allows for wide range of element specific pump-probe experiments in physics, material science and biology. Here we discuss the unique features of the FLASH THz pulses and the accelerator source that bring along a set of challenges in the diagnostics of their key parameters: pulse energy, spectral, temporal and spatial profiles.VII International School and Conference on Photonics : PHOTONICA2019 : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 26-30; Belgrad

    Femtosecond laser spectroscopy for exploration of space

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    Space agencies around the world have the exploration of solar system bodies in the focus of their activities for decades already. The search for traces of life and to a better understanding of the geology of planets, moons and asteroids motivates these explorations. Our (DLR institute for Optical Sensor Systems (DLR-OS)) contribution to this topic is the development of spectroscopic sensors for material identification. DLR-OS is developing a wide range of spectroscopic sensors that reach from passive infrared spectrometers for remote sensing employed on orbiters to active laser spectroscopies such as NIR spectroscopy, Raman spectroscopy or Laser-Induced Breakdown Spectroscopy that are employed on robotic lander missions. Space, weight and power restrictions as well as robustness against harsh environmental conditions are inherent prerequisites for space missions and lead to specific design solutions for these instruments. Driven by emerging technology of space ready short-pulsed (femtosecond) lasers [1,2], we are introducing the new topic of time domain spectroscopies to space exploration. In this work, we present our first results on coherent phonon and THz time domain spectroscopies on space relevant minerals.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad

    Fine-Scale Structure Investigation of Nimonic 263 Superalloy Surface Damaged by Femtosecond Laser Beam

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    Due to the specific conditions of manufacturing, processing and utilization of nickel-base superalloys, the implementation of contemporary precision techniques is necessary in the research of the alloys features. Multi-component nickel-base superalloys, with about of 50% of nickel content, are commonly exploited in the conditions of high temperatures and pressures as well as in various aggressive operating environments. For successful quality control, which includes the monitoring of the changes in the alloy microstructure, fine-scale structure investigations are necessary. In this work, the samples of nickel-base superalloys have been exposed to 800 nm femtosecond laser in various operating regimes. Surface damages and dents caused by femtosecond laser pulses have been observed by optical and scanning microscopy

    Fine-Scale Structure Investigation of Nimonic 263 Superalloy Surface Damaged by Femtosecond Laser Beam

    No full text
    Due to the specific conditions of manufacturing, processing and utilization of nickel-base superalloys, the implementation of contemporary precision techniques is necessary in the research of the alloys features. Multi-component nickel-base superalloys, with about of 50% of nickel content, are commonly exploited in the conditions of high temperatures and pressures as well as in various aggressive operating environments. For successful quality control, which includes the monitoring of the changes in the alloy microstructure, fine-scale structure investigations are necessary. In this work, the samples of nickel-base superalloys have been exposed to 800 nm femtosecond laser in various operating regimes. Surface damages and dents caused by femtosecond laser pulses have been observed by optical and scanning microscopy

    XRF and LIBS measuring on metal and ceramic laser-cleaned surfaces

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    The use of lasers in the conservation of artefacts plays an important role since its posibilities of safe, efficient and efective cleaning on complex surfaces and wide range of materials. This paper presents the results of the laser cleaning effects on ceramic medieval artefacts originated from archaeological sites from region of Tyre and Sidon, Lebanon and naturally tarnished brass plate (unknown origin). Nd: YAG and Er: Glass lasers were used to clean unwanted layers from artefact surface. Before these investigations, some preliminary analyses were conducted on the comparable contemporary samples. Effects on the laser irradiated zones were investigated by optical and SEM microscopy and EDX analysis. LIBS and XRF were used for the morphological and chemical analysis of laser radiation impact on the examined materials. Also surface's profile roughness and surface hardness were measured. Some parameters for successfully and safely cleaning of brass surface without degrading the surrounding material were determined
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