飞秒脉冲在透明介质中的三维光存储及读出对比度研究

将波长为800nm，脉冲宽度为150fs的近红外激光脉冲，聚焦到聚甲基丙烯酸甲酯(Ploymethyl Metacrtlate，简记PMMA)和熔融石英中，实现了三维逐位式光数据存储．分别记录了5，10，15和20层数据位点，并利用相位对比光学显微原理，对各层数据并行读出，从而分析了各层数据位点读出对比度的变化．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，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比PMMA内部产生的残余应力大，因此，在数据位点参数相同的情况下，利用聚甲基丙烯甲酯(PMMA)材料记录的层数更多．

Three-dimensional optical data storage and phase contrast read-out in transparent medium by using femtosecond pulse

Three-dimensional optical data storage in ploymethyl metacrtlate (PMMA) and fused silica is demonstrated by a chirped amplified femtosecond laser pulses at 800 nm,150 fs,1 kHz repetition rate. The writing and reading of the bits in 5,10,15 and 20 layers are presented. The phase contrast 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 the interior to surface of the sample, and the contrast of the interior bits planes will decrease as the number of written layers increase. Due to residual stress in the interaction between femtosecond laser pulse and fused silica, ploymethyl metacrtlate is more suitable for 3-D optical storage with femtosecond laser pulse.