Of Dmd In The Digital Real-time Holographic Applications

Real-time holography, as a method with high precision, high sensitivity and non-destruction, is widely used in flame analysis, stress and vibration analysis, and has received some achievement. With the development of technology, researchers introduced digital technology into real-time holography. Digital real-time holography which uses CCD or CMOS to record the holographic interference fringes which can be stored in the computer instead of traditional holographic plate, then people can reconstruct object's image by computer programming to detect the changing process of objects in real-time.Compared with the traditional real-time holography, digital real-time holography is free from harsh experiment conditions; digital real-time holography is operated more simply and faster. But, the reconstruction process of digital real-time holography can't reach good real-time effect usually because of the limitation of computer speed. As spatial light modulator (SLM) appears, the spatial distribution of light waves can be modulated, we use laser to irradiate SLM and reconstruct object's image by practical light diffraction. Especially digital micro-mirror device (digital micro-mirror device:DMD) with high luminous flux, high diffraction efficiency and quick response is widely used in holographic systems. This paper presents the DMD used in digital real-time holographic reconstruction process, using laser irradiate DMD, we reconstructed the object's image by actual light diffraction. Light computing instead of electricity computing achieved good real-time effect.To verify the feasibility of DMD-based real-time holography, a number of real-time holographic experiments such as temperature field produced by candle or electric iron and stress field of Plexiglas's plate were operated. Compared with results of digital real-time holographic processing, it proved the feasibility of DMD reconstruction method. The impact of low resolution and large pixel size of DMD was also analyzed and discussed, we took full advantage of the benefits of the DMD to achieve the purpose of real-time detection through experiment adjustment ultimately. Finally, with the comparison of other real-time detection methods, this real-time detection system based on DMD optical field reconstruction has full digital advantage and great future.