硫系化物悬吊芯光纤产生温控可调谐超连续谱  

Tunable Supercontinuum Generation in Chalcogenide Suspension Core Fibers via Temperature Control

作　　者：王中垚 张甜甜 施伟华 Wang Zhongyao;Zhang Tiantian;Shi Weihua(College of Electronic and Optical Enghieering&College of Microelectronics,Nanjing University of Posts and Telecommunications,Nanjing,Jiangsu 210023,China)

机构地区：[1]南京邮电大学电子与光学工程学院、微电子学院,江苏南京210023

出　　处：《中国激光》2021年第3期46-54,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(61571237,61275067)。

摘　　要：设计了一种以高非线性三硫化二砷(As2Se3)作为纤芯、以温敏材料甲苯填充包层的悬吊芯光纤,并提出了一种产生可调谐超连续谱(SC)的方法。通过全矢量有限元法数值模拟了光纤中传输光的色散和非线性特性,利用非线性薛定谔方程和分步傅里叶算法分析了在甲苯临界温度为-90~110℃范围内产生的SC,并进行了结构参数和泵浦参量的优化;引入光谱平坦度(SFM)的概念,对模拟产生的SC进行定量分析。研究发现,当光纤纤芯直径为3μm时,利用中心波长为3.1μm、峰值功率为20 kW、脉冲宽度为300 fs的泵浦源可在临界温度下实现1.20μm光谱宽度的调谐;随着可调谐光谱宽度的增大,SFM略有下降,SFM的取值范围为0.89~0.92,这说明SC保持平坦。产生的可调谐SC在物质探测、光谱学和环境分析等领域具有广阔的应用前景。Objective At present,a supercontinuum(SC) has characteristics of wide spectrum,high brightness,and high coherence,and thus it can be widely used in spectroscopy,biomedicine,environmental detection,and other fields.In recent years,the spectral range of SC has covered infrared,ultraviolet,and visible bands.Due to the controllability of the spectral width,the tunable SC has a wider spectrum and an adjustable spectral range,and can be applied in many areas.However,most of the SC studies in current papers are tuning SC range by changing pump source parameters.In addition,the SC tuning range mentioned in some papers is relatively small.Based on the above information,a method for generating tunable SC is proposed in a suspended core fiber with a highly nonlinear arsenic trisulfide(As2 Se3) core and a toluene-filled cladding layer,which is highly sensitive to temperature.In the suspended core fiber,the linear and nonlinear refractive indexes and change in nonlinear coefficient are controlled by the thermal energy through the toluene-filled cladding layer,and a temperature-controlled tunable SC can be generated.Under conditions of unchanged pumping parameters,the spectral width of the SC at different temperatures can be changed by controlling the temperature,and a controllable and tuned SC can be obtained.Methods The dispersion and nonlinear characteristics of the proposed optical fiber were simulated by the full vector finite element method combined with COMSOL Multiphysics software.The generalized nonlinear Schrodinger equation and the split-step Fourier algorithm were used to simulate the optical pulse transmission process in the optical fiber.As2 Se3 was selected as the base material of the optical fiber,and the toluene-filled cladding was filled in the air holes of the optical fiber.The refractive index of the toluene solution changed with temperature,where the maximum difference of refractive index could be 0.105 at the critical temperature range of the toluene solution from-90℃ to 110℃.To obtain the maximum spe

关 键 词：光纤光学 超连续谱 可调谐光谱 悬吊芯光纤 温控 光谱平坦度 

分 类 号：O437[机械工程—光学工程]