Sökning: "mid-IR"

Visar resultat 1 - 5 av 22 avhandlingar innehållade ordet mid-IR.

1. 1. Highly efficient optical parametric oscillators in the mid-IR

   Författare :Nicky Thilmann; Valdas Pasiskevicius; Fredrik Laurell; Klaus Boller; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

   Sammanfattning : This thesis shows how sources of coherent radiation in the mid-infrared (mid-IR) region can be enhanced. To achieve this, optical parametric oscillators (OPOs) employing improved novel materials, new optical elements, and novel cavity designs have been implemented. LÄS MER

3. 2. Mid-infrared photonic devices for on-chip optical gas sensing

   Författare :Floria Ottonello Briano; Kristinn B. Gylfason; Delphine Marris-Morini; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mid-infrared; mid-IR; photonics; silicon photonics; gas sensing; optical sensing; optical gas sensing; spectroscopy; absorption; dispersion; carbon dioxide; CO2; CO2 sensing; trace gas; ethanol sensing; alcohol sensing; waveguide; photonic waveguide; ring resonator; nanowire; nanoheater; emitter; thermal source; bolometer; microbolometer; thermal detector; high frequency; 3 omega method; plasmonic; platinum; Kanthal; silicon-on-insulator; micro-electro-mechanical systems MEMS ; microfabrication; microsystems; microtechnology; nanotechnology; Optik och fotonik; Optics and Photonics; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Gas detection is crucial in a wide range of fields and applications, such as safety and process control in the industry, atmospheric sciences, and breath diagnostics. Optical gas sensing offers some key advantages, compared to other sensing methods such as electrochemical and semiconductor sensing: high specificity, fast response, and minimal drift. LÄS MER

4. 3. Thermal detector with integrated absorber structure for mid-IR gas detection

   Författare :Shakeel Ashraf; Göran Thungström; Peter Enoksson; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal detectors; Thermopile detectors; Infrared absorbers; SU-8 epoxy; Interferometric and Multi-layered absorber; Seebeck coefficient; Molybdenum di-sulfide;

   Sammanfattning : Measurement of the concentration of greenhouse gases, such as carbon dioxide(CO 2 ) and methane (CH 4 ), in the atmosphere has received significant attention in the last few decades. This work focusses on the development of high-performance thermopile detectors for use with the non-dispersive infrared (NDIR) measurements of such gases. LÄS MER

5. 4. Novel materials for Yb and Er-Yb doped microchip lasers

   Författare :Jonas Hellström; Fredrik Laurell; Lars Sjöqvist; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mid-IR lasers; laser materials; Optical physics; Optisk fysik;

   Sammanfattning : The objective of this thesis has been to investigate novel host material configurations for high-power end-pumped Er-Yb co-doped, or Yb doped microchip lasers and try to increase their performance. In Er-Yb co-doped systems, the main limitation is the thermal shortcomings of the phosphate glass host material. LÄS MER

7. 5. Nonlinear optics in KTiOPO4 for spectral management of ultra-short pulses in the near- and mid-IR

   Författare :Anne-Lise Viotti; Valdas Pasiskevicius; Fredrik Laurell; Paulina Kuo; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nonlinear optics; Ferroelectrics; Fysik; Physics;

   Sammanfattning : This thesis explores the possibilities of controlling nonlinear optical interactions in ferroelectric materials for bandwidth tailoring of ultrashort pulses in the pico- and femto-second range. The control is achieved through quasi-phase matching, which is based on alternating the material’s spontaneous polarization into different domains. LÄS MER