Sökning: "Short wavelength"

Visar resultat 16 - 20 av 113 avhandlingar innehållade orden Short wavelength.

1. 16. Integrated Nonlinear Optics in Silicon Nitride Waveguides

   Författare :Clemens Krückel; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; integrated optics devices; nonlinear optics materials; four-wave mixing; nonlinear optical signal processing; wavelength conversion devices; nanostructure fabrication;

   Sammanfattning : Current nanofabrication techniques allow patterning of optical waveguides with submicron cores. This results in strong confinement of light, which leads to high optical intensities. LÄS MER

3. 17. Mode and Polarization Control in VCSELs using Surface Structures

   Författare :Åsa Haglund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; single mode; dynamics; surface relief; Semiconductor laser; polarization; vertical-cavity surface-emitting laser; sub-wavelength grating; fabrication;

   Sammanfattning : The vertical-cavity surface-emitting laser (VCSEL) is a novel, low-cost light source with many attractive performance characteristics, such as low operating current, circular output beam, and high modulation bandwidth at low currents. This together with its easy integration into two-dimensional arrays has made it an established transmitter in short-distance single and parallel fiber-optical links, and new applications are continuously arising. LÄS MER

4. 18. 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

5. 19. VCSEL Cavity Engineering for High Speed Modulation and Silicon Photonics Integration

   Författare :Emanuel Haglund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-speed modulation; on-chip laser source; vertical-cavity surface-emitting laser VCSEL ; semiconductor lasers; optical interconnects; large signal modulation; laser dynamics; heterogeneous integration; vertical-cavity silicon-integrated laser VCSIL ; silicon photonics;

   Sammanfattning : The GaAs-based vertical-cavity surface-emitting laser (VCSEL) is the standard light source in today's optical interconnects, due to its energy efficiency, low cost, and high speed already at low drive currents. The latest commercial VCSELs operate at data rates of up to 28 Gb/s, but it is expected that higher speeds will be required in the near future. LÄS MER

7. 20. Optical Guiding and Feedback Structures in GaN-Based Vertical-Cavity Surface-Emitting Lasers

   Författare :Seyed Ehsan Hashemi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The Vertical-Cavity Surface-Emitting Laser (VCSEL) made from GaAs-based materials is an established infrared light source, and is produced in large volumes for short-distance optical links, computer mice, and thermal processing systems. A wide range of applications, such as high-resolution printing, general lighting, and biomedical diagnosis and treatment could benefit from using a VCSEL with blue or ultraviolet emission. LÄS MER