Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 14 of 14 for “"Back-reflection"”.
-
Characterization of Optical Coupling and Back-reflection of Few Mode Fibers
… setup is demonstrated, and the major issue of back reflection burying the intended signal is addressed, analyzed, and improved. Improvements in the signal-to-background contrast ratio (SBCR) of approximately 10dB were achieved depending on fibre type and proximal face. Suggestions for …
-
Preferred orientations in rolled metals, construction of pole figure by back-reflection method
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Metallurgy, 1943.
-
Influence of High Temperature Creep upon the Structure of ß-NiAl and ß-NiAl(Fe) Single Crystals
… the structure parameters according to the X-ray reflection intensity. Specifically, two special single crystal X-ray diffraction methods, namely the back reflection Kossel technique and the back reflection Laue method, are applied for the determination of lattice parameter and for the collection …
-
External cavity laser label-free biosensor
… illumination of the photonic crystal and direct back-reflection into the amplifier. We demonstrate single-mode, mode-hop-free, biomolecule-induced tuning of the continuous-wave laser wavelength. Because the approach incorporates external optical gain that is separate from the transducer, the …
-
Lattice parameter and thermal expansion in solid methane
… in the range 2.5 to 86.2 K with a precise, back-reflection x-ray camera. The lattice parameters differ significantly from previous imprecise values in the literature. A first-order transition with a discontinuity in the lattice parameter of 0.1% was unambiguously observed to occur at 20.48 K …
-
Low temperature bulk modulus of solid argon
… at constant temperature using a high precision back-reflection X-ray camera. Low temperature measurements, using helium as the pressure transmitting fluid, are reported which cover the pressure range of 10 to 300 bar. These measurements, which are the first direct measurements on a free-standing …
-
Lattice constant, thermal expansion, and isothermal compressibility measurements on argon single crystals
… as a function of temperature with a precision, back-reflection x-ray diffractometer. From this determination the total thermal expansion and the coefficient of thermal expansion have been obtained. Also', a preliminary measurement has been made on the isothermal compressibility of solid argon at …
-
Resolution limits and process latitude of comformable contact nano-lithography
… optimized trilayer stack design of 225nm of anti-reflection-coating chemically separated from the resist by 70nm of evaporated silicon oxide. This design results in less than 1.5% back-reflection from the oxide into the resist for 10% film thickness variation. Finite-difference time-domain …
-
Dynamic state-space estimation of the hemodynamic response with Near-Infrared Spectroscopy
… of the head as well as in the brain tissue. The back-reflection geometry of the measurement makes the DOI signal strongly contaminated by systemic interference occurring in the superficial layers. A recent development has been the use of signals from small source-detector separation (1 cm) …
-
Electron-reflector strategy for CdTe thin-film solar cells
… is a conduction-band energy barrier at the back surface of the solar cell, which can reduce the recombination due to the electron flow to the back surface. Different methods to create an electron reflector are explained in the thesis: (1) expanded band gap, either an expanded-band-gap layer …
-
Materials, methods and concepts for 21st century solar cells
… is explained in Chapter 1. Chapter 2 gives a background to solar panels, semiconductors and thesis relevant materials while main experimental and theoretical tools used are introduced in Chapter 3. Spectroscopic measurements are used to better understand recombination and passivation in halide …
-
Crystal growth of functional oxides using an image furnace
… dispersive x-ray analysis, x-ray diffractometry, back reflection x-ray Laue, polarised optical microscopy and vibrating sample magnetometry. The best quality TiO\(_2\) crystals were prepared when neither the growing crystal nor the feed rod were rotated during crystal growth. When rotation was …
-
Optimized grating coupler designs for integrated photonics
… analysed suggesting that 0.6dB are due to back-reflection from the optics interfaces, and 0.4dB due to spherical aberrations. Moreover, a detailed analysis of the manufacturing and alignment tolerances is conducted demonstrating their compatibility with current standard packaging processes.
-
Crosstalk and Signal Integrity in Ring Resonator Based Optical Add/Drop Multiplexers for Wavelength-Division-Multiplexing Networks
… and waveguides. Optical EMC issues are due to backscatter, crosstalk, stray light, and substrate modes. This thesis has focused on the crosstalk in Optical Add/Drop Multiplexers (OADMs) as an EMC problem. The main research question is: “How can signal integrity be improved and crosstalk effects …