산화 방식을 도입한 광양자테 레이저의 연구

Abstract

We have reported the photonic quantum ring (PQR) laser that exhibits ultra-low threshold currents and -dependent spectral red shifts, and thus the PQR is offering a better possibility for low power consumption and high density integration of smart pixel arrays. These PQR characteristics show a potential of outdoing light emitting diode (LED). This thesis proposes the PQR laser fabricated with an oxidation method which provides the reflection region needed for the PQR laser. In chapter 2, we demonstrate how to fabricate the oxide-distributed Bragg reflector (DBR) PQR laser. It gives a possibility for replacing the vertical cavity surface emitting laser (VCSEL) wafer by the resonant cavity light emitting diode (RCLED) wafer that is cheaper and easily found. In chapter 3, we describe the properties of the oxide-DBR PQR laser. I-V curves are analyzed to study electrical characteristics and the relation of Rayleigh band length and oxidation depth. The inverse dependence of series resistance on aperture size is due to the increased size of the conductive cross-sectional area, which is in agreement with Ohm’s law and increase optical scattering loss in the case of small-sized oxide apertures. The spectrum of the emitted light was measured using a portable spectrometer and single mode fiber (9/125μm). Spectra for the oxide-DBR PQR are quite distinct from those of conventional 3D PQR, thus we study the reason of this appearance using 3D ray analysis model. Consequently, PQR laser with oxide-DBRs have surface-normal dominant modes. We improve the performance of PQR laser through oxidation method and this oxidation technology will help a fabrication of blue PQR based GaN.