相位对比读出三维光数据存储的实验研究

使用波长800 nm、脉冲宽度150f s的近红外激光脉冲紧聚焦到PMMA（聚甲基丙烯酸甲酯）和熔融石英中实现了三维逐位式光数据存储,分别记录下了5、10、 15和20层数据位点.利用相位对比光学显微原理对各层数据并行读出,实验分析了各层数据位点的读出对比度的变化.结果表明:各层数据位点的折射率对比度由内至外依次增加,记录层数越多,其内部层的对比度下降越明显.由于飞秒激光脉冲与透明介质相互作用中,熔融石英内部产生的残余应力比PMMA内大,因此数据位点参数相同的情况下,利用PMMA材料记录的层数更多.

Experimental Study of Phase Contrast Reading out of Three-dimensional Optical Data Storage

Three dimensional optical data storage in PMMA(ploymethyl metacrtlate) and fused silica is demonstrated by a chirped amplified femtosecond laser pulses at 800 nm,150 fs,1kHz repetition rate. The writing and reading of the bits in 5,10,15 and 20 layers are presented. The signal/noise ratio (S/N) of multi layers bits reading by a phase contrast optical microscope is analyzed experimentally and the phase contrast change of each bits plane is given. The results show that the phase contrast of each layer increases monotonously from interior to surface of the sample, and the contrast of the interior bits planes will be decreased as the number of written layers increased. Due to residual stress in the interaction between femtosecond laser pulse and fused silica, PMMA is more suitable for 3 D optical storage with femtosecond laser pulse.