Applications and developments of digital holography
Digital holography is a new technology emerged in 1994. Because of developments of Laser, personal computer, and CCD sensor, digital holography is finding a remarkably wide range for applications. The reconstruction algorithm is the corner stone of digital holography. It simulates and models the optical reconstruction process with numerical algorithms. A number of reconstruction algorithms have been developed for digital holography in recent years, for instance, the digital implementations of the Fresnel transform, the Fraunhofer transform, and Wavelet transform. We examined all above reconstruction algorithms and developed our own variants of Angular Spectrum and Wavelet/Chirplet reconstruction algorithms. Further to these reconstruction algorithms, we developed miscellaneous algorithms to make digital holography more sophisticated. To detect the focus of an individual hologram, auto-focusing algorithms are developed. To break the resolution limitation introduced by the CCD sensor we present digital in-line holography illuminated by divergent light and corresponding reconstruction algorithms. To expand digital holography in a wider range of common applications, digital video holography is exploited. The holographic video can be reconstructed in both z and time axes. We integrated all the algorithms into software for holographic recording and processing electronically. We also applied the digital holography in a real biological application, sediment erosion study.