경사진 도파로를 가지는 고휘도 레이저 다이오드 설계 및 제작

Abstract

SLDs(Superluminescent Laser Diodes) are known as proper optical sources for the optical measurements, since their properties are intermediate between those of the LEDs and LDs. And it is expected that the demands of SLD will be increased with the progress of optical industries.

In this research, we proposed a novel SLD with a window region without AR coating(Anti-Reflection coating). Also the active region consists of straight and tilted waveguide. The straight waveguide is introduced to have high power, and the window region and tilted waveguide were introduced to suppress lasing oscillation. The most important thing is that the facet reflectivity of SLD has to be lowered than 10-4 for a stable operation without lasing oscillation.

The reflectivity of window region and laterally tilted angle was calculated with the gaussian beam approximation and mode analysis. Based on the theoretical analysis, we designed and fabricated the SLD with 50㎛ window region and 7o tilted stripe. And then we measured the optical characteristics of SLD. The fabricated SLD has 3mW output power under continuous wave driving and 0.8dB spectrum ripple at room temperature.

From the results, we confirm that the proposed SLD is possible to apply for the semiconductor optical amplifier in integrated device with arrayed DFB-LD, and the light source of fiber-optic gyroscope and optical coherence tomography system.