光学技术, 2019, 45 (1): 40, 网络出版: 2019-04-16
基于铯133原子D1线直接吸收光谱的多普勒展宽热力学温度测量
Doppler broadening thermodynamic temperature measurement based upon direct laser absorption spectroscopy on Cs133 D1 line
热力学温度测量 多普勒展宽 直接吸收光谱 铯133原子D1线 thermodynamic temperature measurement Doppler broadening direct laser absorption spectroscopy Cs133 D1 line
摘要
玻尔兹曼常量的定值致使温度测量逐步从协议温标向热力学温标过渡。为实现一种量子化的热力学温度测量传感方案,利用直接吸收光谱方法精密测量铯133原子D1(6S1/2→6P1/2)跃迁吸收谱线,依据谱线多普勒展宽分量获得原子气体在该平衡态下的热力学温度。实验验证将外腔扫描激光器输出频率锁定于精密波长计,实现1000s稳定时长条件下10-9量级的频率稳定度; 通过振幅型声光调制器闭环控制实现优于1000∶1的测量信噪比; 通过福格特线型拟合得到多普勒展宽半高全宽宽度。在室温条件下,初步结果显示温度测量误差为0.12%。由此验证了基于原子直接吸收光谱的多普勒展宽测温方法可用来实现芯片尺度、免标定的热力学温度测量。
Abstract
Fixing Boltzmann constant in SI unit redefinition directly impacts temperature measurement regarding to merging current used the international temperature scale to thermodynamic temperature scale. In order to reach a quantum thermodynamic temperature sensing, this research implemented a Doppler broadening thermometry which takes advantages of direct laser absorption spectroscopy on Cs133 D1(6S1/2→6P1/2 transition) line to retrieve Doppler broadened linewidth, and calculated the thermodynamic temperature of the thermal-equilibriumed atomic gas. The proof-of-concept experiment locked frequency of beam of an external cavity diode laser to a high-precision wavelength meter obtaining a 10-9 short term stability at 1000 second period, stabilized probe beam by the use of an intensity modulated acousto-optic modulator elevating signal-to-noise ratio to above 1000:1, and fitted the detected absorption spectral line using the Voigt line shape. The preliminary result showed that, under room temperature, the error of the measurement could reach 0.12%. It is verified that the Doppler broadening temperature measurement method based on atomic direct absorption spectroscopy can be used to realize chip-scale and calibration-free thermodynamic temperature sensing.
廖文汉, 潘奕捷, 王贺, 武梦萱, 冉洁, 姚燕, 屈继峰. 基于铯133原子D1线直接吸收光谱的多普勒展宽热力学温度测量[J]. 光学技术, 2019, 45(1): 40. LIAO Wenhan, PAN Yijie, WANG He, WU Mengxuan, RAN Jie, YAO Yan, QU Jifeng. Doppler broadening thermodynamic temperature measurement based upon direct laser absorption spectroscopy on Cs133 D1 line[J]. Optical Technique, 2019, 45(1): 40.