在数字散斑干涉(DSPI)测量方法中，数字散斑时间平均法测量振动时得到的是贝塞尔条纹，其定量分析比较困难。该文采用贝塞尔条纹准相移技术进行数字散斑振动定量分析，即在参考光路中引入和物体同频率的偏置参考振动，当参考振动的相位改变时，振动条纹会产生移动，这相当于静态余弦条纹的相移，可以采用相移算法对数字散斑振动测量的贝塞尔条纹进行定量分析。文中开发了一种新的数字散斑振动定量分析系统，研制了一种低压光学相移器和测量控制电路，给出了圆周固定圆片和四周固定方铜板的振动测量结果。实验结果表明：采用本系统可以方便地定量测出物体的振动模态。

Vibration measurement by digital speckle pattern interferometry (DSPI) has the merits of high precision,no-contact and full-field measurement. Because the fringes achieved by the DSPI time-average vibration measurement are Bessel fringes,its quantificational analysis is difficult. The quasi-phase-shifting technique of Bessel fringes is used for the DSPI vibration quantificational analysis. A bias reference vibration at the same frequency is introduced into the reference beam as an object vibration. The Bessel fringes will shift when the phase of the bias reference vibration changes,which is equivalent to the phase-shifting of cosine fringes. So the Bessel fringes of DSPI vibration measurement can be analyzed quantitatively through the phase-shifting algorithm. A novel DSPI system for vibration quantificational analysis is developed. A low voltage phase-stepper and the measurement control electric circuit are designed and fabricated. The vibration testing results of a circumference fixed circular disc and a four-side mixed square copper piece are given. The vibration modality can be measured conveniently through this system,and the quality of the measurement result is good.