空间分辨率优化分布的光学时域延展单像素成像系统的研究

超高速实时成像是观测和研究瞬时物理现象、化学反应、细胞演化等不可或缺的工具。作为最常用的成像器件，CCD和CMOS成像速率通常限制于1kHz，远不能满足高速实时成像的需求。光学时域延展单像素成像是超高速成像的新兴技术手段，该方法利用空间频谱编码、色散傅里叶变换和时序编码，将被测目标的空间信息编码于时域延展光脉冲的时间序列上，并通过光电二极管探测和示波器采样并形成图像，成像速率可大于100MHz。然而超高速成像产生的大量数据对于采集和存储提出了巨大挑战，昂贵的采集和存储设备都极大的提高了实验成本，也很大程度上限制了光学时域延展成像系统的小型化和实用化。本项目拟基于光学时域延展成像的原理，建立实验系统参数与成像分辨率之间的关联，结合现代光学设计方法并根据目标的信息分布优化成像分辨率，利用非等间隔采样的方法有效压缩总数据量，为突破高速成像数据采集和传输的瓶颈提供支持。

Ultrafast real-time optical imaging is a powerful tool for observing fast dynamic phenomena, for instance, physical process, microfluidics, chemical reaction and cell evolution. Nevertheless, traditional CCD (Charge-coupled device) and their complementary CMOS (Complementary metal-oxide-semiconductor) counterparts are incapable of capturing fast dynamical processes with high sensitivity and resolution. As a newly emerging technique for ultrafast imaging, photonic time stretch image (PTSI) utilizes the procedures of spatial spectrum coding, dispersive Fourier transformation and temporal coding to perform the images. The information of object is normally coded in the time serials of light pulse and then is captured by a high-speed photodiode and a wide bandwidth oscilloscope, the imaging frame of which could beyond 100 MHz. However, huge data generated by the ultrafast imaging system puts forward great challenges to sampling and storage. High-priced sampling and storage devices not only greatly increases the cost of PSTI experiment, but also largely restricts the miniaturization and practicality of the PSTI system. Based on the principle of time stretch imaging, we will firstly establish an appropriate theoretical model to describe the relationship between image resolution and experimental parameters of the system. In the project, the key procedure is effectively compressing the total data of the image in view of non-uniform sampling method, which is based on the spatial distribution of the object and modern optical design method. The research achievements will offer strong support to break the technical bottleneck of data sampling and storage for ultrafast PTSI systems.