Ultrafast Photonics

超快光子学是光子学的前沿课题之一，由活跃的大学研究人员作为成员组织合作研究。典型成果有：Yamashita教授提出了利用非线性光学效应展宽光谱产生单周期光脉冲的方案，H.Ito教授利用准相位匹配技术利用可见光泵浦参量振荡器产生了高效的相干THz辐射，Yanshita教授提出了利用非线性光学效应展宽光谱产生单周期光脉冲的方案，Yanshita教授提出了利用准相位匹配技术利用可见光泵浦参量振荡器产生相干THz辐射的方案，Yanshita教授提出了利用非线性光学效应展宽光谱产生相干THz辐射的方案，Yanshita教授提出了利用准相位匹配技术产生相干THz辐射的方案，Yanshita教授提出了利用非线性光学效应展宽光谱产生相干THz辐射的方案。K.K.菊池教授针对超长距离光纤的情况，通过四波混频，阐明了使用中途光谱转换进行色散补偿的条件，T.Kamiya改进了基于半导体激光器的飞秒脉冲源，并提出了一种新的基于非线性光纤开关的全光信号转换方案。Tsuchiya发现了锁模半导体激光器通过射频信号注入实现的次谐波同步，并讨论了其在毫米波光子网络中的应用。F.Koyama改进了垂直腔半导体激光器（VCSEL）的特性，特别强调偏振稳定。S.Noda研究了利用子带间光跃迁控制半导体量子阱威尔斯中的带间跃迁。利用自由电子激光泵浦，实现了超快光开关。小林将频谱控制的思想推广到时间波形控制，并讨论了各种方法的优点。

Collaborative research on ultrafast photonics which is one of the leading edge topics of photonics is organized with active university researchers as members. Typical achievements are summarized : Prof.M.Yamashita proposed a scheme of generating monocycle optical pulse by broadening optical spectra using nonlinear optical effect ; Prof.H.Ito generated efficiently coherent THz radiation via parametric oscillator pumped by visible laser using quasi-phase matching techuique ; Prof.K.Kikuchi calrified the condition of dispersion compensation usng mid-way spectral conversion by four wave mixing for the case of ultra-long distance fiber-optic trans-oceanic transmission system with multiple wavelength ; T.Kamiya improved semicoductor-laser-based femtosecond pulse source and also proposed a new all optical signal conversion scheme using nonlinear fiber-optic switch. M.Tsuchiya discovered the subharmonic synchronization of mode-locked semiconductor laser by means of rf signal injection and discussed its application to milliwave photonic network. F.Koyama improved the characteristics of vertical cavity semiconductor lasers (VCSELs), with special emphasis on polarization stabilization. S.Noda investigated the control of interband transition in semiconductor quantum wells via intersubband optical transition. Using free electron laser pump, ultrafast optical switching capability was demonstrated. T.Kobayashi extended the idea of controlling temporal waveform by the control of spectrum and discussed the merits of different apporaches.