| Summary: | 碩士 === 國立臺灣大學 === 光電工程學研究所 === 91 === Photonic crystals are crystal structures with periodic variation of material refractive indices or dielectric constants. The periodicity can be one, two, or three dimensional. When light propagate in photonic crystals, it will experience continuous reflection, refraction, and scattering. As a result, light within some specific wavelength ranges cannot propagate in some directions.
The aim of this work is the fabrication of three-dimensional photonic crystals with the face-centered cubic structure. We apply the auto-cloning technique [1,2,3], which is by means of alternating deposition of two materials with different refractive indices on a two-dimensional pre-patterned substrate. We adopt the GaAs material system. The Al0.98Ga0.02As/Al0.3Ga0.7As alternating layers will be deposited on a GaAs template. After wet oxidation from the lateral direction, a three-dimensional Al0.3Ga0.7As/AlxOy photonic crystal is formed. We use also the software Rsoft to simulate the photonic band structures and compare our results with those in the literature [3].
We have successfully fabricated a series of three-dimensional face-centered-cubic photonic crystals. Through the optical transmission measurement, the existence of photonic band-gap is demonstrated in the 1300nm~1500nm near-infrared wavelength range and the bandgap position shows red-shift with increasing the feature size of the photonic crystals. Furthermore, we also fabricate photonic crystals with line defects. From our preliminary results, the line-defect modes are observed. Systematic investigations on these structures will be carried out in the future to explore the properties of defect modes.
|
|---|
