摘要
自混合激光多普勒测速(laser Doppler velocimetry,LDV)精度与激光器模式、多普勒信号频率展宽、激光器前腔镜到反射面距离(外腔长)的变化范围以及速度的动态范围等因素密切相关,研究结果表明,采用新型小功率单模垂直腔表面发射激光器(vertical-cavity surface-emitting laser,VCSEL)和模拟差频锁相技术,在外腔长度为30 mm±1 mm,速度范围为30～480 mm/s,采样时间为0.1 s的条件下,测速精度优于1%,重复精度优于0.2%,具有测速精度高、动态范围大、成本低等特点.
A self-mixing laster Doppler velocimetry（LDV） with a new single mode verticalcavity surface-emitting laser （VCSEL） is proposed. The results show that the accuracy of velocity measurement is related to laser mode, Doppler signal spectrum width, dynamic range of the length between the laser front mirror to surface （the external cavity length）, and dynamic range of velocity. The single mode laser and analog beat-frequency phase-locked loop （PLL） technique were used in the self-mixing LDV, and the accuracy of velocity measurement improved noticeably. With the external cavity length being 30 mm±1 mm, the velocity range between 30 mm/s and 480 mm/s and sampling time 0. 1 s, the accuracy of velocity measurement is better than 1%, and repeatable accuracy is better than 0. 2%. The self-mixing LDV has many characteristics, such as high accuracy of velocity measurement, wide dynamic range and low cost, etc.
