Author Affiliations
Abstract
1 State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai200062, China
2 Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan030006, China
3 Science and Technology on Electronic Test & Measurement Laboratory, The 41st Research Institute of CETC, Qingdao266000, China
We report on the generation of a mid-infrared (mid-IR) frequency comb with a maximum average output power of 250 mW and tunability in the 2.7–4.0 μm region. The approach is based on a single-stage difference frequency generation (DFG) starting from a compact Yb-doped fiber laser system. The repetition rate of the near-infrared (NIR) comb is locked at 75 MHz. The phase noise of the repetition rate in the offset-free mid-IR comb system is measured and analyzed. Except for the intrinsic of NIR comb, environmental noise at low frequency and quantum noise at high frequency from the amplifier chain and nonlinear spectral broadening are the main noise sources of broadening the linewidth of comb teeth, which limits the precision of mid-IR dual-comb spectroscopy.
fiber laser mid-infrared optical frequency comb High Power Laser Science and Engineering
2020, 8(4): 04000e32
华东师范大学精密光谱科学与技术国家重点实验室, 上海 200062
基于非线性放大环形镜,设计了一种全正色散掺镱光纤锁模激光器。在抽运功率为80 mW的情况下,该掺镱光纤锁模激光器可以实现平均功率为7.8 mW的稳定输出。输出激光脉冲的重复频率为9.9 MHz,中心波长为1064 nm,脉冲宽度约为18 ps,相应的光谱宽度为0.18 nm。该激光器具有结构简单、自启动、稳定性高的优点。
激光器 锁模激光器 光纤激光 掺镱激光 非线性光纤光学
中国科学院上海技术物理研究所 红外物理国家重点实验室, 上海 200083
采用磁控溅射法分别制备了不同组分的Mn-Co-Ni-O(MCNO)薄膜材料.通过对材料结构分析, 发现在Mn离子数目不变的情况下, 随着Co离子的增加, 晶粒尺寸逐渐增大, 且晶格常数先增大后减小; 在Co离子数目不变的情况下, 随着Mn离子的增加, 薄膜的择优生长晶面由(311)不晶面向(400)晶面转变.对电学性能测试进行分析, 可知薄膜材料既有Mn离子的导电机制, 也有Co离子的导电机制; Mn1.2Co1.5Ni0.3O4具有最低的电阻率(235 Ω·cm), 具有最高的室温负温度电阻系数︱α295︱(4.7%·K-1)值.
MCNO薄膜 电学特性 电阻率 激活能 MCNO thin films electrical properties resistivity activation energy
中国科学院上海技术物理研究所 红外物理国家重点实验室，上海200083
采用磁控溅射法制备了厚度为6.5 μm的Mn1.95Co0.77Ni0.28O4组分的薄膜材料，把材料分别在400℃，500℃，600℃，700℃，800℃下进行后退火处理.结果表明，室温下的负电阻温度系数α295值随退火温度增加先增大后减小，而电阻率ρ295则是随退火温度增加逐渐减小的；在相同频率下，500℃退火样品的归一化噪声谱密度 (SV·VR/V2) 最小，700℃退火样品的归一化噪声谱密度最大.退火温度越高会造成越多的晶体缺陷，从而降低有效导热系数、增大时间常数τ和器件噪声.
Mn1.95Co0.77Ni0.28O4薄膜 器件性能 退火温度 探测率 响应率 Mn1.95Co0.77Ni0.28O4 thin films detector properties annealing temperature detectivty responsivity
