Optimizing the ordering of the Hadamard masks of ghost imaging suitable for the efficient face reconstruction using the max-projection method.

One crucial component of ghost imaging (GI) is the encoded mask. Higher-quality reconstruction at lower sampling rates is still a major challenge for GI. Inspired by deep learning, max-projection method is proposed in the paper to reorder the Hadamard masks for its efficient and rapid reconstruction.

Characterization of the error of the speckle-based wavefront metrology device at Shanghai Synchrotron Radiation Facility.

A metrology device based on the near-field speckle technique was developed in the x-ray test beamline at the Shanghai Synchrotron Radiation Facility to meet the at-wavelength detection requirements of ultra-high-precision optical elements. Different sources of error that limit the uncertainty of the instrument were characterized. Two main factors that contribute to the uncertainty of the measurements were investigated: (1) noise errors introduced by the electronics and the errors introduced by the algorithm and (2) stability errors owing to environmental conditions.

Generation of picosecond pulses with variable temporal profiles and linear polarization by coherent pulse stacking in a birefringent crystal shaper.

We report the study and demonstration of a new laser pulse shaping system capable of generating linearly polarized picosecond laser pulses with variable temporal profiles including symmetric intensity distributions, as well as non-symmetric distributions, which are highly desired by various applications. It is found that both high transmittance and high stability of the shaped pulse can be achieved simultaneously when crystals are set at a specific phase delay through fine control of the crystal temperature. Although multi-crystal pulse stacking with different configurations was reported before particularly for flattop pulse generation, this new configuration leads to new opportunities for many potential applications over a wide range of laser wavelengths, pulse repetition rate, time structures and power levels.