Research On Aberration Compensation Of Non-interference Phase Reconstruction Of Holographic Optical Storage

In today’s era of big data,with the continuous development of computer technology,information exchanges in people’s daily life are becoming more and more frequent,and a large amount of new data is generated.Massive data makes the current traditional storage technology unable to meet the demand for data storage capacity and data conversion rate.People put forward higher requirements for the carrier of information — — storage technology: larger storage capacity,higher storage density and faster access speed.As a three-dimensional storage technology,holographic optical storage technology has been widely studied again because of its ultra-high storage density and ultra-fast data conversion rate.Starting from the holographic optical storage technology,aiming at the disadvantages of poor signal-to-noise ratio and low coding rate of the current traditional amplitude holographic data storage technology,this paper introduces a more efficient phase holographic data storage technology.Therefore,this paper mainly focuses on the phase holographic data storage technology.In the phase encoding stage,the effect and advantages of phase modulation,the relationship between phase order and encoding rate are analyzed.In the phase decoding stage,a non-interference decoding method is adopted,compared with the traditional interferometric decoding,the non-interference decoding system has a simpler structure and more stable reading results.Using the iterative Fourier transform algorithm,combined with the embedded data added in the phase encoding stage,can achieve more efficient phase reconstruction.The objective lens used in holographic storage system for information recording has complex structure,large volume and heavy weight,which is not conducive to the rapid recording and reading of information and the miniaturization of the system.When recording with a single lens,it will bring large aberration noise.These aberration noise will distort the wavefront of the light field,and then change the Fourier intensity,which will affect the subsequent phase reconstruction.The main research content of this paper is to establish the scalar diffraction theoretical model of light field with wavefront aberration,and simulate the influence of different types of aberration on phase reconstruction by Zernike polynomial.The principle of phase conjugation is proposed.The gray image of conjugate aberration combined with phase coding information is loaded on the liquid crystal spatial light modulator,so as to compensate the Fourier intensity affected by wavefront aberration.Simulation and experimental results show that under the same number of iterations,the signal-to-noise ratio of the Fourier intensity after aberration compensation is higher,the bit error rate of phase reconstruction is lower,and the phase reconstruction effect is better.The significance of the aberration compensation method is to optimize the structure of the optical system and achieve the goal of lightweight optical system.