Sökning: "Ferroelectrics"

Visar resultat 6 - 10 av 27 avhandlingar innehållade ordet Ferroelectrics.

1. 6. Nanosecond optical parametric oscillators and amplifiers based on periodically poled KTiOPO4

   Författare :Jonas Hellström; KTH; []
   Nyckelord :optical parametric oscillators; optica parametric amplifiers; quasi-phasematching; KTiOPO4; nonlinear optics; frequency conversion; periodic electric field poling; ferroelectrics; high-order second harmonic generation; electro-optic effect;

   Sammanfattning : Optical parametric oscillators (OPOs) and optical parametricamplifiers (OPAs) constitute a class of optical frequencyconverting devices that have many possible applications, e.g.in range finding, molecular spectroscopy and medicine. LÄS MER

3. 7. High Temperature Superconducting and Tunable Ferroelectric Microwave Devices

   Författare :Erik F. Carlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; varactors; tunable microwave circuits; conformal mapping; cryogenic probe station; ferroelectrics; high temperature superconductors; microwave circuits; narrow-band filters; phase-shifter;

   Sammanfattning : This thesis addresses some applications of High Temperature Superconductors (HTS) and ferroelectric materials in tunable microwave devices and circuits. The work is divided into three main areas: i) modeling of multilayered structures including ferroelectric layers, ii) realization and characterization of tunable coplanar waveguides (CPW), capacitors and resonators based on ferroelectrics, and iii) an investigation of microstrip HTS K-band filters. LÄS MER

4. 8. Engineering ferroelectric domains and charge transport by proton exchange in lithium niobate

   Författare :Michele Manzo; Katia Gallo; Marin Alexe; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lithium niobate; Ferroelectrics; Teknisk materialvetenskap; Materials Science and Engineering; Fysik; Physics;

   Sammanfattning : Ferroelectrics are dielectric materials possessing a switchable spontaneous polarization, which have attracted a growing interest for a broad variety of applications such as ferroelectric lithography, artificial photosynthesis, random and dynamic access memories (FeRAMs and DRAM), but also for the fabrication of devices for nonlinear optics, etc. All the aforementioned applications rely on the control of the ferroelectric domains arrangement, or the charge distribution and transport. LÄS MER

5. 9. Processing and On-Wafer Test of Ferroelectric Film Microwave Varactors

   Författare :Jang-Yong Kim; Alexander Grishin; Dag Winkler; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; : ferroelectrics; sodium potassium niobates; silver tantalite niobate; barium strontium titanate; thin films; pulsed laser deposition; rf magnetron sputtering; coplanar waveguide; photolithography; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Sammanfattning : Microwave materials have been widely used in a variety of applications ranging from communication devices to military satellite services, and the study of materials properties at microwave frequencies and the development of functional microwave materials have always been among the most active areas in solid-state physics, materials science, electrical and electronic engineering. In recent years, the increasing requirements for the development of high speed, high frequency circuits and systems require complete understanding of the properties of materials function at microwave frequencies. LÄS MER

7. 10. Electro-Optical Na0.5K0.5NbO3 Films

   Författare :Mats Blomqvist; Alexander M. Grishin; Prof. Bruce Wessels; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Functional materials; ferroelectrics; sodium potassium niobates; thin films; rf-magnetron sputtering; waveguiding; refractive index; prism-coupling; electro-optic effects; dielectric tunability; Funktionella material; Functional materials; Funktionella material;

   Sammanfattning : Ferroelectric oxides are a group of advanced electronic materials with a wide variety of properties useful in applications such as memory devices, resonators and filters, infrared sensors, microelectromechanical systems, and optical waveguides and modulators.Among the oxide perovskite-structured ferroelectric thin film materials, sodium potassium niobate or Na0. LÄS MER