Effect of Internal Optical Loss on Threshold Characteristics of Semiconductor Quantum Dot Laser

• Main Authors: Po-Hung Lin, 林柏宏
• Other Authors: Tei-Chen Chen
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/16327456701063159649

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 93 === 　The technology of quantum dot laser has attracted great attention recently due to the low threshold current density, higher characteristic temperature, and wider modulation band-width. Its applications include the read write head of the CD-ROM drive, infrared remote sensing the optical fiber and so on. Theoretically, we can find that the more level occupancy in the absence of internal loss, the more intensity of laser will be generated. Considering the fixed external loss and the internal loss on the threshold characteristics, the free-carrier density does not pin in the presence of light generation, and the free-carrier-density dependence of internal loss gives rise to the existence of the second lasing threshold above the conventional threshold. Above the second threshold, the light–current characteristic is two-valued up to a maximum current at which the lasing is quenched. As the temperature effect is concerned, we obtain a range form 270K to 307K under specific conditions. When the temperature becomes higher, the range between two lasing thresholds will be less than the case of lower temperature. In additions, the structure critical tolerable parameters are closely dependent on temperature.