High saturation power anti-waveguide asymmetric super-large optical cavity SOA with low confinement factor and ultra-narrow vertical divergence angle

• Published in: Applied physics letters 2024-11, Vol.125 (22)
• Main Authors: Hao, Shuang, Liu, Suping, Qi, Qiong, Xiong, Cong, Chang, Jinyuan, Zhu, Lingni, Wei, Xin, Ma, Xiaoyu
• Format: Article
• Language: English
• Subjects: Asymmetry; Confinement; Epitaxial growth; Light amplifiers; Light sources; Power amplifiers; Quantum wells; Semiconductor optical amplifiers; Waveguides
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0240831

As a power amplifier in nonlinear frequency conversion, semiconductor optical amplifiers around 1 μm can effectively realize the miniaturization of the light source system. In this paper, a low confinement factor anti-waveguide asymmetric super-large optical cavity semiconductor optical amplifier (AT-SLOC-SOA) with high saturation power is reported. We introduced a high-refractive-index mode filtration layer under the n-cladding layer, ensuring fundamental mode output in the epitaxial direction while reducing the optical confinement factor to 0.615% per quantum well. The SOA exhibits a fundamental mode in the epitaxial direction with an ultra-narrow vertical divergence angle of merely 13.8°, which can enhance the fiber coupling efficiency. At 20 °C and 3 A, the AT-SLOC-SOA showed a peak wavelength of 1017.15 nm and a −3 dB spectral bandwidth of 27.491 nm. The small-signal gain reaches a maximum of 22.3 dB, with a −3 dB saturated output power up to 26.4 dBm and a maximum output power as high as 30 dBm. The fabrication process utilizes conventional epitaxial growth and etching techniques to ensure low cost and high reliability while achieving high saturated output power.