提出了一种基于光时分复用技术的高速成像系统。飞秒激光器中心波长1557 nm,脉冲宽度90 fs,对USAF-1951分辨率板线性扫描成像,扫描频率为38.88 MHz。在连续时间序列编码放大显微成像技术的基础上,运用光时分复用技术,复制光脉冲信号并携带检测物体相同的空间信息。原光脉冲和复制光脉冲以相同的采样率分别采样,通过相应的数据处理将两次采样数据整合在一起还原图像。实验结果表明,与传统的超快成像方法相比,成像系统利用10 GHz的数字采样设备可以达到20 GHz的采样率,采样点数是传统超快成像方法的两倍。该方法有效克服了成像系统采样率不足的问题,提高了成像系统的空间分辨率。与此同时,该系统算法复杂程度不高,有利于进一步促进超高速成像技术的发展。

Ultrafast imaging system based on optical time-division multiplexing is proposed. A femtosecond fiber laser with center wavelength 1557 nm and pulse width about 90 fs, is used in the line-scan imaging system at 38.88 MHz for observing the USAF-1951 standard resolution test target. Based on the serial time-encoded amplified microscopy (STEAM) technology with the optical time-division multiplexing to achieve high resolution of ultrafast imaging, the imaging system has two times the sampling rate and the pixel number of the image is doubled. The result of the experiment demonstrates that the imaging system has achieved 20 GHz sampling rate by employing a 10 GHz of digital sampling device and doubling the sampling points comparing with the conventional ultrafast imaging system. The problem of low pixel number is addressed and image quality is enhanced effectively.