Study of Inter-Track Crosstalk in Holographic Read Only Memory to Determine Optimal Track Format

홀로그래픽 롬 시스템의 최적 트랙 포맷을 결정하기 위한 인접 트랙간 간섭 현상에 대한 연구

The effects of track format on the inter-track crosstalk of holographic ROM system are investigated. To quantify the effect of inter-track crosstalk for various track width and pitch, we defined Signal to Crosstalk noise Ratio(SCR) as a criterion. A numerical simulation is used to obtain the SCR as a function of track widths and pitches. We compared different 4 track widths having 0.3, 0.4, 0.5, and 0.6 ${\mu}m$ considering resolving power of lens and recording density. The simulation results show that the SCRs for each track width are maximized at the track pitch which has the value of 0.72, 0.72, 0.74, and 0.5 ${\mu}m$ respectively. Next, for the three sets with track width-pitch(0.4-0.72, 0.5-0.74, 0.6-0.8 ${\mu}m$) which showed the maximum SCR, we set a minimum pit length so that all sets have a DVD equivalent data density and compared RF signals passed from the slit. The simulation results show that when the track width, pitch, and minimum pit length have 0.5, 0.74, and 0.4 ${\mu}m$ respectively, the difference between the maximum and minimum value of the RF signal showed the greatest value. Also, we investigated RF signal in case of using an amplitude inversion mask, which transmitted regions are inversed against the conventional mask. The simulation results show that the better RF signal may be obtained by using an amplitude inversion mask.