基于Y型腔正交偏振激光器的微纳力值传递标准技术

In this project, we present a novel micro-nano force transfer artefact technique based on Y-shaped cavity orthogonal polarized He-Ne laser and mainly study its principles comprehensively. The main research contents include:(1)Adopting Lamb semi-classical gas laser theory and gas lasers kinetics theory, the effects of different factors on frequency difference lock-in threshold and their mechanism will be investigated and summarized detailedly, with the aid of experiments. Subsequently, the scheme aiming at achieving laser's zero lock will be put forward. By finite element analysis software ANSYS, thermodynamics model of laser will be built. Based on simulation analysis and experiments, the laser's optimal geometric parameters will be designed to reduce the temperature variation's effect on laser's frequency difference stability.(2)Applying differential equations for the elastic curved surface of circular flat diaphragm and Lamb semi-classical gas laser theory, a nonlinear correction to the ideal principle formula of micro-nano force transfer artefact will be carried out. Then the modified formula will be validated through the experiments. (3)The theoretical relationship between the low force transfer artefact's measurement error and force parameters including load position and direction will be established. Based on Lamb semi-classical gas laser theory and experiments, the effect of laser's operating point on measurement error and its mechanism will be analyzed. Then the rules of various interference factors' effects on measurement errors in the measurement environment will be researched on.This project will establish the corrected principle model and measurement error model of micro-nano force transfer artefact. The principle prototype of low force transfer artefact will be also developed. All of researches above are aimed at providing a theoretical basis for the development of our original micro-nano force transfer artefact technique.

本项目提出一种基于Y型腔正交偏振激光器的微纳力值传递标准技术，对其原理进行较为全面的研究。主要内容包括：（1）采用兰姆半经典理论、气体激光动力学理论，结合实验，研究影响频差闭锁阈值的因素及其影响机理，提出实现激光器零闭锁的方案；采用ANSYS建立激光器热力学模型，仿真分析与实验研究结合，对其几何参数进行优化设计,以减小温度变化对激光器频差稳定性的影响。（2）采用大挠度情况下平膜片弹性曲面方程和兰姆半经典理论，结合实验研究，对理想情况下传递标准仪的原理公式进行非线性修正。（3）建立力作用点和力作用方向与传递标准仪测量误差之间的理论关系；采用兰姆半经典理论，结合实验分析激光器工作点对测量误差的影响机理；通过实验分析测量环境中各干扰因素对传递标准仪的影响规律。通过上述研究，建立微纳力值传递标准技术的理论体系，包括修正的原理模型和测量误差模型，为我国微纳力值传递标准技术的发展提供理论基础。

微纳力值测量技术是纳米科技发展的重要基础研究之一，微纳力值传递标准技术又是微纳力值测量准确性和一致性的前提，但国际上微纳力值溯源体系仍未完全建立起来。本项目原创性地提出并研究了基于Y型腔正交偏振激光器的微纳力值传递标准技术，完成了项目总体目标。项目的主要研究进展如下：（1）采用气体激光动力学理论和兰姆（Lamb）半经典理论，建立了激光器模式耦合参量与起工作参数之间关系的理论模型，结合实验研究，总结了这些参数对频差闭锁阈值的影响规律和影响机理，通过优化参数，无磁场情况下频差闭锁阈值达到10MHz以下，这是迄今为止国际上公开报道的双频激光器的最小频差闭锁阈值。（2）首次推导出模式耦合参量与横向磁感应强度之间的解析表达式，在理论指导下优化设计并自制了具有均匀磁场分布的方体磁场线圈，实验表明当磁感应强度值大于0.01特斯拉时，激光器闭锁阈值频差降至KHz量级，有效抑制了频差闭锁。以上关于Y型腔正交偏振激光器的两项研究进展丰富了双频激光器的门类，进一步完善了双频激光器的学术体系。（3）利用ANSYS有限元软件建立了激光器的温度场模型，仿真分析与实验结合研究了激光器的稳态温度场分布特点、瞬态温度变化趋势，还通过实验研究了环境热对流对激光器温度分布的影响规律。综合优化激光器测试条件和测试环境，短时频差稳定性达到7.3KHz。（4）采用兰姆半经典理论，推导了激光器的频差修正公式，采用大挠度下集中力问题的完整解析解，推导出微纳力值传递仪原理公式的非线性修正项。开展了大挠度情况下微力测试实验，结果与非线性修正后的原理公式符合地较好。（5）开展了力作用点引起的力测量误差实验研究，表明力作用点是限制微纳力值传递标准仪精度提高的另一个主要因素。设计制作了激光器的拍频频率检测和微纳力值传递标准仪工作点控制电路，提出了待测力类型鉴别方法。分析了目前微纳力值传递标准仪的性能指标，力值测量范围为6.1μN-7.99mN，动态范围1.3×10^3。