Study on optical short-pulse generation from intensely excited gain-switched semiconductor lasers

2016 Fiscal Year Final Research Report

• Project/Area Number: 26390075
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Optical engineering, Photon science
• Research Institution: National Institute of Advanced Industrial Science and Technology (2016); The University of Tokyo (2014-2015)
• Principal Investigator: YOSHITA MASAHIRO 国立研究開発法人産業技術総合研究所, 太陽光発電研究センター, 主任研究員 (30292759)
• Co-Investigator(Renkei-kenkyūsha): AKIYAMA Hidefumi 東京大学, 物性研究所, 教授 (40251491)
• Research Collaborator: CHEN Shaoqiang 華東師範大学, 教授 ; ITOH Takashi 東京大学, 物性研究所, 博士研究員 ; NAKAMURA Takahiro 東京大学, 物性研究所, 学生 ; NAKAMAE Hidekazu 東京大学, 物性研究所, 学生
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 半導体レーザー / 利得スイッチング動作 / 超短パルス / 光エレクトロニクス / 光学非線形効果 / 光源技術

Outline of Final Research Achievements

Lasing performance of gain-switched semiconductor lasers under intense excitation was systematically studied. At low photo-excitation, optical pulses were generated in accordance with a conventional rate-equation analysis in a gain-switched GaAs bulk laser. However, as the photo-excitation intensity increased, the pulse width of the generated optical pulses became shorter and simultaneously spectrally broadened toward shorter-wavelength region, which was not explained by the conventional rate-equation analysis. It was also confirmed that the pulse width at the shorter-wavelength region of the optical pulses was shorter than 1 ps. The generation mechanisms of the observed unique optical pulses under intense excitation were discussed with a phenomenological carrier-dynamics model taking into account transient energy distributions and intra-band relaxations of the photo-excited carriers in the active gain region.

Free Research Field

工学