时间： 2014年4月24日(周四) 上午10：00
主讲人：英国帝国理工大学 张梦 博士
张梦博士，现为英国帝国理工大学物理学院博士后研究员，主要从事非线性光学领域的研究，在超快锁模激光器和超连续谱方面取得了显著的成绩，并在Laser Physics Review、Optics Express等光学重要期刊和会议上发表一批论文。张梦博士2007年本科毕业于天津大学精密仪器与光电子工程学院，获得电子信息工程专业学士学位。2010年硕士毕业于北京大学信息科学技术学院，师从区域光纤通信国家重点实验室张志刚教授，获得了无线电物理专业的硕士学位。2013年博士毕业于英国帝国理工大学物理学院，师从非线性光学领域权威Taylor教授。目前在帝国理工大学进行博士后阶段研究。
Nonlinear optics enables the manipulation of spectral and temporal characteristics of optical pulses interacting with a dielectric medium. Optical fibres, as a uniquely practical medium, provide an environment for effectively exploiting the nonlinear effects. This has facilitated the rapid growing interest in this field focused on the investigation of fibre based sources incorporating with various novel saturable absorber devices for ultrashort pulse generation
In this seminar, I will report a series of experiments exploring the ongoing research in the field of nonlinear optics, including the development of ultrafast mode-locked fibre sources and their applications in supercontinuum generation.
Firstly, the integration of carbon-based materials with rare-earth doped media allows the demonstration of ultrafast mode-locked laser sources operating at wavelengths across the near-infrared region in a compact, low-cost and environmentally robust scheme. Power scaling of such sources can be achieved by operating in the all-normal dispersion regime making use of a glass-substrate saturable absorber device that exhibits a higher damage threshold. Additionally, the demonstration of a simple and compact nano-material based dual-wavelength system shows the performance of such devices as a simultaneous saturable absorber and passive synchroniser.
Supercontinuum generation has been used as an effective method for spectral broadening. Pumping with a conceptually simple and reliable fibre-based system, a continuum covering from 2 to 3 μm is generated in a high nonlinear GeO2 fibre. This experiment demonstrates a robust and long-term stable source of radiation in an important band, coincident with a portion of the atmospheric transmission window.