高功率飞秒光梳相干合成新方法研究

项目名称： 高功率飞秒光梳相干合成新方法研究

项目编号： No.11504235

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 杨康文

作者单位： 上海理工大学

项目金额： 24万元

中文摘要： 高精度宽谱带的飞秒光梳在时频域精密光谱测量、物质成分检测、表面形貌分析等领域都有着广泛的应用。飞秒光梳光谱范围向紫外、极紫外以及中红外、远红外拓展，都离不开高功率高精度的飞秒光梳作为驱动源。大模场光纤制造工艺的成熟以及啁啾脉冲放大技术的广泛应用，推动了高功率飞秒光梳的发展。然而，随着飞秒光梳功率的提高，光纤中的非线性不断增大，放大器输出脉冲的时频域特性发生畸变，放大过程中累积的附加相位噪声将严重影响高功率飞秒光梳的精度。本项目采用主动式相干合成技术，结合自相似放大技术与超短脉冲载波包络相位控制方法，突破单一放大器的功率极限，实现高功率高精度飞秒光梳。对于单路光纤放大器，自相似放大技术有效利用放大过程中的自相位调制效应，克服增益窄化，有利于提高飞秒光梳控制的精度；对于相干合成方式，采用基于最小值寻找算法的主动式结构，研究合成过程中脉冲时频域特性、偏振态特性对合成效果的影响。

中文关键词： 光纤激光；高功率放大；光纤飞秒光梳；相干合成

英文摘要： Optical femtosecond frequency combs with high accuracy and broadband spectral range have many applications in the fields of precision spectroscopy, matter composition analysis and surface topography measurement. Especially for the application of ultraviolet or mid-infrared frequency comb generation, high-power high accurate femtosecond frequency combs are essential to acting as the driving sources. The advanced large-mode-area fiber manufacturing technology and the widespread use of chirped pulse amplification method promote the development of high-power optical femtosecond frequency combs. However, with the increase of output power, the nonlinear effects during amplification will distort the pulse characteristics in time and frequency domain and thus affect the accuracy of high-power femtosecond frequency combs. Based on the proposed coherently combining of optical femtosecond frequency combs, this program has the potential to break through the limitation of single fiber amplifier and generate high-power high accuracy femtosecond frequency combs by the use of self-similar amplification and carrier-envelope phase control methods. The nonlinear effects, especially the self-phase modulation, were used to compensate the gain narrowing in amplification process via pre-chirp management amplification method. We used active phase control method which is based on minimum-searching algorithm to investigate coherently combining of femtosecond frequency combs, and provide a possible solution for high-power high accuracy femtosecond frequency combs both in theory and experiment.

英文关键词： fiber laser;amplifier;fiber femtosecond frequency combs;coherent combing