Unsymmetry Spiked Multiple-Quantum-Well Design and Electroabsorption Modulators Integrated Semiconductor Optical Amplifier Based on the InGaAsP/InGaAlAs Material system

• Main Authors: Ding-Guo Li, 李定國
• Other Authors: Yi-Jen Chiu
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/63072831223388930043

碩士 === 國立中山大學 === 光電工程研究所 === 94 === Semiconductor optical amplifiers (SOA) and electroabsorption modulators (EAM) have been become vital elements to obtain high-output-power and high-speed optical signal in the optical fiber communications. In this paper, we propose a novel type cascaded integrated SOAs and EAMs, which are monolithically integrated in the same chip without any regrowth. In the active region, high electron bandgap offset material, InGaAsP/InAlGaAs, is used in order to get high optical gain and also high modulation. Using cascaded SOAs and EAMs, high impedance of microwave stripe lines are the bridges connecting the small EAM elements, bring up higher impedance and thus enhancing the microwave transmission. The optical waveguide is made by selectively undercut etching InGaAsP/InAlGaAs material in order to reduce the optical scattering loss and also the microwave loss due to the low parasitic capacitance. The processing is described by the following steps: (1) ion implantation to get electrical isolation; (2) wet etching to form the optical waveguide ridge; (3) e-gun evaporation to get n- and p- metalization ; (4) spinning PMGI as planarization; (5)Final thick metalizations as for microwave transmission line. The final integrated cascaded SOAs and EAMs has been successfully fabricated and measured. In comparison with single EAM, higher than 10GHz of –3dB electrical transmission has been found, indicating the cascaded integration structure has better impedance matching and also higher electrical transmission. The measured optical gain is higher than 5dB with 11dB/V modulation efficiency at excitation wavelength of 1568nm.