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Based on the secondary rainbow principle,three kinds of glass beads with typical refractive indices 1.90,1.93 and 2.2 are measured by semiconductor lasers with three different wavelengths(632.8 nm,532 nm and 404 nm).Then dispersion functions are determined according to Cauchy function and experimental results,which show that the normal dispersion characteristic belongs to the glass beads but with the large amount.By analyzing whether the dispersion has effect on retroreflective capability with different incident angles from 0° to 90°,it shows that the retroreflective capability of glass beads with refractive index 2.2 is inferior to those of 1.90 and 1.93.Additionally,the energy distribution of retroreflect lights in the paraxial region is simulated by ray tracing method.And the results indicate that the retroreflective energies of glass beads with refractive indices 1.90 and 1.93 are mainly concentrated in the range of 5°.

A method was proposed to evaluate visual fatigue in autostereoscopic displays by measuring the pupil diameter of viewers.And a pupil diameter measuring device was presented to record the viewers′ pupil diameter when the viewers watch three-dimensional videos.The conclusion was made that the degree of visual fatigue increases as the increase of viewing time according to viewers′ subjective evaluation,and experiments shown that the pupil diameter increases as the increase of the degree of visual fatigue.As a result,the pupil diameter can be used as a new measurement index of visual fatigue.The variation of viewers′ pupil diameter is 0.4 mm when viewers′ visual fatigue is medium which can be considered as a critical value of viewing comfort.

A realization of 3D-mouse is proposed.By the principle of stereo vision,the method based on autostereoscopic Display can make the common mouse point to any location at different depths in three-dimensional space which can be perceived by the viewers.And,a method of calculating the real position’s depth is also proposed and is verified experimentally.Theoretical analysis and experiment results show that the method of the realizing 3D-mouse and calculating the real position’s depth can make the autostereoscopic display be introduced into the digital photogrammetric system.