1 天津大学精密测试技术及仪器国家重点实验室, 天津 300072
2 北京航天计量测试技术研究所, 北京 100076
针对调频非线性和快速傅里叶变换（FFT）精度不高的问题，基于等光频间隔重采样的调频连续波测距系统，采用相位差测频法测量了待测目标点的距离；对调频连续波激光测距原理进行分析和推导，并依靠该系统进行了测距稳定性和测距误差的分析实验。结果表明：在8.3～9.3 m测量范围内，相位差测频法的测距单点稳定性范围为50～95 μm，测得的距离与理论距离的残余误差不超过100 μm；所提算法比快速傅里叶变换具有更好的测距精确性和稳定性。
测量 相位差测频 等光频间隔重采样 调频连续波 测距精度 中国激光
2018, 45(11): 1104002
天津大学精密仪器与光电子工程学院,激光与光电子研究所,天津大学教育部光电信息技术科学重点实验室, 天津 300072
传统的大模场光纤是通过设计光纤结构来获得大模场面积的,可以实现的模场面积只能达到几百平方微米。增益导引和折射率导引相结合是实现大模场单模光纤的一种新方法。通过分析增益因子对折射率以及归一化频率的影响,得到了光纤中各阶模式截止条件与纤芯包层折射率差和增益因子的关系。最后以包层折射率为1.5734,纤芯折射率为1.5689,纤芯半径为50 μm,10%(原子数分数)重掺杂钕离子的磷酸盐光纤作为模拟计算对象,当波长为1.064 μm时,得到其模场直径大于90 μm。对于普通光纤,增益导引和负折射率导引相结合的方法对实现大模场单模传输很有前景。
光纤光学 光纤激光器 大模场单模光纤 增益导引 折射率导引
Tieli Zhang 1,2,3,*Baigang Zhang 1,2,3Haifeng Li 1,2,3Feng Ji 1,2,3[ ... ]Jianquan Yao 1,2,3
Author Affiliations
Abstract
1 College of Precision Instrument and Opto-Electronics Engineering, Institute of Laser and Opto-Eletronics, Tianjin University, Tianjin 300072
2 Cooperated Institute of Nankai University and Tianjin University, Tianjin 300072
3 Key Laboratory of Opto-Electric Information Science and Technology (Ministry of Education), Tianjin University, Tianjin 300072
We report a tunable quasi-phase-matched optical parametric generator (OPG) with different wedge angles, pumped by a commercially available Q-switched diode-pumped Nd:YVO4 laser with a repetition of 50 kHz. The nonlinear crystal is a periodically poled MgO-doped LiNbO3 (PPMgOLN) with a period of 30 um. A congruent bulk LiNbO3 (LN) with three different wedge angles of 0, 4, and 9 deg. is placed in front of PPMgOLN. Rapid tuning has been achieved by simply moving the LN crystal along its lateral direction and over 60-mW average signal output power was obtained in the whole wavelength tuning range of 1539-1570 nm.
190.2620 Frequency conversion 190.4410 Nonlinear optics, parametric processes 190.4970 Parametric oscillators and amplifiers Chinese Optics Letters
2006, 4(4): 04234
