Research of Single Lightpath Rainbow Hologram Based on Digital Micro-Mirror

The utilization rate of optical wave energy is limited because of the use of slit in the rainbow hologram technology.A new method of making rainbow hologram is proposed.Due to the special two dimensional grating structure of digital micro-mirror,a number of spectrum points would be formed in the back focal plane of the Fourier transform lens.In the diffraction spread of these spectrum points from the back focal plane to the imaging plane,these spectrum points are expanding continuously.These points superpose completely in the imaging plane except the zero level spectrum points.Interference fringes have been observed.As a result,we can make the approximate rainbow hologram without slit and reference beam,by use of the characteristic of digital micro-mirror.In this paper,we have discussed some related theory in detail and described the experiment about it.In the experiment,we have recorded the image by the dry plate and also acquired the laminated hologram by rotating the dry plate.Under the microscope,we can watch the interference fringe clearly.And we can survey the rainbow spectrum in the white light.