Toshihiro Fujiki

Numerical analysis of real-time holography in bacteriorhodopsin films

A flexible numerical method for analyzing diffraction of real- time holograms written in bacteriorhodopsin films is described. The method calculates the propagation of writing and reading beams in bac- teriorhodopsin films using the finite-differential beam propagation method. The changes of the films in refractive index and absorption are deduced from rate equations for B-state and M-state molecules. We ap- ply this method to a real-time holographic lens and calculate the spot profile on the focal plane and the diffraction efficiencies for various pa- rameter values. We also measured diffraction efficiencies experimentally and compared the values with numerical results.

Recent progress in electron beam mastering for 100Gb/in2 and beyond

We improved the electron beam recorder with a differential pumping head for higher density discs and mass production. The beam diameters were improved by exchanging the aperture size of the objective lens and beam stability were also improved by adding a sound proof case. As for the performance of the improved electron beam recorder, we showed that a 104Gb/in2 (150GB capacity/layer) density disc with EFM plus modulation codes can be fabricated. We also improved the pit shape uniformity and a margin of the process by introducing the appropriate write strategy that is simulated by the Monte Carlo simulation to the recording pulses.