Experimental and Theoretical Study on 3D Photonic Crystals

1. Improvement of polarization splitter characteristicsBy optimizing the shape of a unit cell of thecrystal, extinction ratio, insertion lossand their performance for angled-incidence case are improved. In addition，by adjusting the thickness of surface layersanti- rection termination was made possible.2. Development of photonic crystals in visible rangeWehave made photonic crystals for visible wavelength range with TiO - D22 - D2/Ta - D22 - D2O - D25 - D2material systems. By utilizing it，我们也有demonstrated birefringent plates and polarization-sensitive gratings.3. Investigationfor brand-gap wideningWe have theoretically demonstrated an feasibility of the absolute bandgap bycombination of the autocloning technology and RIE etching process.已有经验4. Proposal of novel optical waveguidesWe have proposed novel opticalwaveguides by an introduction of lattice-modulation into the autocloned crystals. Results ofnumerical calculations revealed that such waveguide structure wseful for practicalapplications.5. Combination of functional materials and autocloned photonic crystalsWe havedeveloped processes which enable introduction of Group II-IV materials such as CdS and Group III-Vcompound semiconductors such as GaAs into autocloned photonic crystals. Photoluminescencecharacteristics也被监测。

1. Improvement of polarization splitter characteristicsBy optimizing the shape of a unit cell of the crystal, extinction ratio, insertion loss, and their performance for angled-incidence case are improved. In addition, by adjusting the thickness of surface layers, anti-reflection termination was made possible.2. Development of photonic crystals in visible rangeWe have made photonic crystals for visible wavelength range with TiOィイD22ィエD2/TaィイD22ィエD2OィイD25ィエD2 material systems. By utilizing it, we have also demonstrated birefringent plates and polarization-sensitive gratings.3. Investigation for brand-gap wideningWe have theoretically demonstrated an feasibility of the absolute bandgap by the combination of the autocloning technology and RIE etching process. Preliminary experiments have been also carried out.4. Proposal of novel optical waveguidesWe have proposed novel optical waveguides by an introduction of lattice-modulation into the autocloned crystals. Results of numerical calculations revealed that such waveguide structure were useful for practical applications.5. Combination of functional materials and autocloned photonic crystalsWe have developed processes which enable introduction of Group II-IV materials such as CdS and Group III-V compound semiconductors such as GaAs into autocloned photonic crystals. Photoluminescence characteristics were also observed.