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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 211 for “"Mid-infrared"”.
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Mid infrared spectroscopic imaging and tomography
Fourier Transform Infrared (FT-IR) Spectroscopic Imaging is an optical technique that simultaneously provides morphological (two dimensional) and mid-infrared spectral (one dimensional) information for a specimen under observation. In this dissertation, we develop a new instrument that extends the …
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Parametric amplification of mid-infrared picosecond radiation
High power, tunable, mid-infrared sources are important in many fields, like spectroscopy and medical applications. This thesis presents a technique for realising a high power tuneable mid-infrared picosecond source, by combining the radiation from a free electron laser with a powerful Nd:YAG pump …
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GaAs/AlGaAs mid-infrared quantum cascade laser
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.
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Characterization of mid-infrared quantum cascade lasers
… highest output powers available for light in the mid-infrared range (from 3 to 8 m). As many of their applications require portability, designs that have a high wall-plug efficiency are essential, and were designed and grown by others to achieve this goal. However, because a large fraction of …
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Femtosecond optical parametric oscillators for the mid-infrared
… of femtosecond pulses in the near and mid-infrared spectral regions. The three optical parametric oscillators which were constructed were synchronously- pumped by a self-modelocked femtosecond Ti:sapphire laser. Noncollinear critical birefringent phasematching was used in an oscillator …
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Mid-Infrared Integrated Devices for Optical Chemical Sensing
The mid-infrared (MIR) spectral range is of special interest for establishing optical chemical sensor technologies by allowing specific molecular identification and quantification, whether the sample is in a liquid, gas or solid form, in addition to providing highly sensitive, rapid, reagent-free …
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Novel dilute nitride semiconductor materials for mid-infrared applications
A new approach to room temperature mid-infrared applications in the 3 -5 µm spectral range has been proposed through the development of novel dilute nitride materials. InAsN shows a large bandgap reduction with a small lattice mismatch when a small amount of nitrogen is introduced into the host …
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Mid-infrared optical absorption in undoped lamellar copper oxides
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1994.
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Technologies for Room-Temperature Mid-Infrared Photodetection using Graphene
Mid-infrared light is used for thermal imaging, relying on thermal radiation, and chemical analysis, based on vibrational absorption spectra. Ironically, these applications require detector materials and architectures with resilience to thermal noise and infrared-transparent optical materials with …
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Low-Temperature Germanium Waveguides for Mid-Infrared Sensing Applications
Waveguide integrated devices that operate in the mid-infrared (mid-IR) wavelength range (2.5-12 µm) are used for sensing the fundamental absorption bands in a variety of molecules. Germanium (Ge) is commonly used for photodetection in the nearinfrared (near-IR) wavelength range of 1.2-1.6 µm due to …
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Mid-Infrared Spectral Characterization of Aflatoxin Contamination in Peanuts
Contamination of peanuts by secondary metabolites of certain fungi, namely aflatoxins present a great health hazard when exposed either at low levels for prolonged times (carcinogenic) or at high levels at once (poisonous). It is important to develop an accurate and rapid measurement technique to …
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Optically Pumped Type-II Mid-Infrared Tunable Distributed Feedback Lasers
Optically-pumped type-II mid-infrared index-coupled tunable distributed feed- back (DFB) semiconductor lasers have been developed to provide continuous-wave (CW) single longitudinal mode (SLM) operation with features including narrow spec- tral linewidth, high output power, good beam quality and …
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Calibration of MIDI, the Mid-infrared Interferometer for the VLTI
Das MIDI-Instrument (MID-infrared Interferometric Instrument) wird am VLTI (Very Large Telescope Interferometer) stellare Langbasisinterferometrie im N-Band (8...13µm) durchführen. Im Vorfeld des Aufbaus von MIDI waren einige vorbereitende Aufgaben zu lösen, die die Kalibrierung des Instruments im …
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Progress in sensitive mid-infrared spectroscopy of cooled molecular ions
The spectroscopic investigation of molecular ions is key to facilitating a better understanding of chemical and physical processes that occur both here on Earth and among distant stars. However, numerous challenges are encountered when attempting to study these highly reactive species in the …
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Thermomechanical sensitivity of microcantilever in the mid-infrared spectral region
… sensitivity of bimaterial cantilevers over a mid-infrared (IR) spectral range (5-10 µm) that is critical both for chemical analysis via vibrational spectroscopy and for direct thermal detection in the 300-700 K range. Mechanical bending sensitivity and noise were measured and modeled for six …
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Discrete frequency mid-infrared spectroscopic imaging using quantum cascade lasers
Infrared (IR) spectroscopic imaging is an analytical technique that directly images the spatial distribution of chemical components within a sample in the absence of external contrast agents. This is especially advantageous with biological samples where the mid to far-infrared wavelength range …
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The mid-infrared spectrum of lightly doped La₂CuO₄₊y
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1997.
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A novel single-cycle optical source in the mid-infrared
… generation of single-optical-cycle pulses in the mid-infrared, which are generated using adiabatic difference frequency in an aperiodically polled lithium niobate crystal. The input pulses were generated in amplified Ti:Sapphire laser system, the construction of which is covered in detail, along …
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A novel few-cycle optical source in the mid-infrared
… exceptionally short optical pulses in the mid-infrared, tunable from 2-4[mu]m with pulse widths as low as 1.5 optical cycles at 3.5[mu]m (18fs). Energies as high a 1[mu]J were achieved, representing a peak power of roughly 100MW, at a 1kHz repetition rate, with excellent beam quality. The …
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