High-sensitivity laser confocal tomography based on frequency-shifted feedback technique

Laser confocal tomography faces severe challenges in weak signal detection such as biological tissue imaging and low-reflection interfaces measurement. An ultra-high sensitive optical confocal tomography based on laser frequency-shifted feedback imaging technology is presented, whose theoretical magnification can reach 10(6) notably without using high-gain detectors. In addition, this achievement possesses the same tomographic resolution as conventional laser confocal tomography without the need for spatial filtering devices. In this work, supported by theories and experiments, the lateral and vertical resolution, optical sensitivity, and system repeatability of LFCT and traditional LCT are investigated and analyzed quantificationally. Finally, comparison on the results of measuring the microfluidic device and biological tissue sections is conducted.