关键词: 激光, 折射指数, 干涉相移效应, 毛细管电泳

Abstract: This paper describes a novel optical interference effect, namely retroreflective laser beams interference phase-shift effect. When a focused He-Ne laser beam passes through a cuvette containing liquid sample, the two reflective beams (retroreflective beams)coming from the front and the back surfaces of the cuvette will recombine and generate optical interference effect. The optical-phase-shift between retroreflective beams at the time t depends upon the changes in refractive index of the sample △n. It has been deduced that the relative change of signal intensity at the detector is proportional to △n under the condition of △nl<<λ, where l is the length of the sample within the cuvette and λ is the laser wavelength.The possibility of determining the small changes in the concentration of micro-volume sample was verified experimentally. Its application to the capillary electrophoresis detector was also demonstrated.

Key words: Laser, Refractive index, Interference phase-shift effect, Capillary electrophoresis