Xie Chenbo

Polarization-multiplexing ghost imaging

Abstract A novel technique for polarization-multiplexing ghost imaging is proposed to simultaneously obtain multiple polarimetric information by a single detector. Here, polarization-division multiplexing speckles are employed for object illumination. The light reflected from the objects is detected by a single-pixel detector. An iterative reconstruction method is used to restore the fused image containing the different polarimetric information by using the weighted sum of the multiplexed speckles based on the correlation coefficients obtained from the detected intensities. Next, clear images of the different polarimetric information are recovered by demultiplexing the fused image. The results clearly demonstrate that the proposed method is effective.

Simultaneous fusion, imaging and encryption of multiple objects using a single-pixel detector

A novel technique for the simultaneous fusion, imaging and encryption of multiple objects using a single-pixel detector is proposed. Here, encoded multiplexing patterns are employed to illuminate multiple objects simultaneously. The mixed light reflected from the objects is detected by a single-pixel detector. An iterative reconstruction method is used to restore the fused image by summing the multiplexed patterns and detected intensities. Next, clear images of the objects are recovered by decoding the fused image. We experimentally obtain fused and multiple clear images by utilizing a single-pixel detector to collect the direct and indirect reflected light. Technically, by utilizing the patterns with per-pixel exposure control, multiple objects’ information is multiplexed into the detected intensities and then demultiplexed computationally under the single-pixel imaging and compressed sensing schemes. An encryption experiment is performed by setting the multiplexed patterns’ encoding as keys.

New mobile Raman lidar for measurement of tropospheric water vapor

The content of water vapor in atmosphere is very little and the ratio of volume of moisture to air is about 0.1%–3%, but water vapor is the most active molecule in atmosphere. There are many absorption bands in infrared (IR) wavelength for water vapor, and water vapor is also an important factor in cloud formation and precipitation, therefore it takes a significant position in the global radiation budget and climatic changes. Because of the advantages of the high resolution, wide range, and highly automatic operation, the Raman lidar has become a new-style and useful tool to measure water vapor. In this paper, first, the new mobile Raman lidar’s structure and specifications were introduced. Second, the process method of lidar data was described. Finally, the practical and comparative experiments were made over Hefei City in China. The results of measurement show that this lidar has the ability to gain profiles of ratio of water vapor mixing ratio from surface to a height of about 8 km at night. Meanwhile, the measurement of water vapor in daytime has been taken, and the profiles of water vapor mixing ratio at ground level have been detected.