We propose a new algorithm for wavefront sensing based on binary intensity modulation. The algorithm is based on the fact that a wavefront can be expended with a series of orthogonal and binary functions, the Walsh se...We propose a new algorithm for wavefront sensing based on binary intensity modulation. The algorithm is based on the fact that a wavefront can be expended with a series of orthogonal and binary functions, the Walsh series. We use a spatial light modulator（SLM） to produce different binary-intensity-modulation patterns which are the simple linear transformation of the Walsh series. The optical fields under different binary-intensity-modulation patterns are detected with a photodiode.The relationships between the incident wavefront modulated with the patterns and their optical fields are built to determinate the coefficients of the Walsh series. More detailed and strict relationship equations are established with the algorithm by adding new modulation patterns according to the properties of the Walsh functions. An exact value can be acquired by solving the equations. Finally, with the help of phase unwrapping and smoothing, the wavefront can be reconstructed. The advantage of the algorithm is providing an analytical solution for the coefficients of the Walsh series to reconstruct the wavefront. The simulation experiments are presented and the effectiveness of the algorithm is demonstrated.展开更多
We propose a simple gradation representation method using a binary-weighted computer-generated hologram（CGH） to be displayed on a high-speed spatial light modulator that can be controlled by the pulse-width modulati...We propose a simple gradation representation method using a binary-weighted computer-generated hologram（CGH） to be displayed on a high-speed spatial light modulator that can be controlled by the pulse-width modulation technique. The proposed method uses multiple bit planes comprising binary-weighted CGHs with various pulse widths. The object points of a three-dimensional（3D） object are assigned to multiple bit planes according to their gray levels. The bit planes are sequentially displayed in a time-division-multiplexed manner.Consequently, the proposed method realizes a gradation representation of a reconstructed 3D object.展开更多
A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform im...A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform image is produced by purposely shifting the holographic images of multiple reconstructed lights with different incident angles from the zero-diffraction-order and overlapping those selected different orders. The simulation and optical experimental results show that the influence of the zero-diffraction-order can be reduced, while keeping the good uniformity of the target images by this new approach.展开更多
基金Project supported by the National Innovation Fund of Chinese Academy of Sciences(Grant No.CXJJ-16M208)the Preeminent Youth Fund of Sichuan Province,China(Grant No.2012JQ0012)the Outstanding Youth Science Fund of Chinese Academy of Sciences
文摘We propose a new algorithm for wavefront sensing based on binary intensity modulation. The algorithm is based on the fact that a wavefront can be expended with a series of orthogonal and binary functions, the Walsh series. We use a spatial light modulator（SLM） to produce different binary-intensity-modulation patterns which are the simple linear transformation of the Walsh series. The optical fields under different binary-intensity-modulation patterns are detected with a photodiode.The relationships between the incident wavefront modulated with the patterns and their optical fields are built to determinate the coefficients of the Walsh series. More detailed and strict relationship equations are established with the algorithm by adding new modulation patterns according to the properties of the Walsh functions. An exact value can be acquired by solving the equations. Finally, with the help of phase unwrapping and smoothing, the wavefront can be reconstructed. The advantage of the algorithm is providing an analytical solution for the coefficients of the Walsh series to reconstruct the wavefront. The simulation experiments are presented and the effectiveness of the algorithm is demonstrated.
基金supported by the Japan Society for the Promotion of Science through a Grantin-Aid for Scientific Research(C)15K00153+1 种基金a Grant-in-Aid for Scientific Research(A)25240015
文摘We propose a simple gradation representation method using a binary-weighted computer-generated hologram（CGH） to be displayed on a high-speed spatial light modulator that can be controlled by the pulse-width modulation technique. The proposed method uses multiple bit planes comprising binary-weighted CGHs with various pulse widths. The object points of a three-dimensional（3D） object are assigned to multiple bit planes according to their gray levels. The bit planes are sequentially displayed in a time-division-multiplexed manner.Consequently, the proposed method realizes a gradation representation of a reconstructed 3D object.
基金supported by the UK Engineering and Physical Sciences Research Council(EPSRC) for the support through the EPSRC Centre for Innovative Manufacturing in Ultra Precision(EP/I033491/1)
文摘A simple and effective approach is proposed to minimize the effect of unmodulated light and uneven intensity caused by the pixelated structure of the spatial light modulator in a holographic display. A more uniform image is produced by purposely shifting the holographic images of multiple reconstructed lights with different incident angles from the zero-diffraction-order and overlapping those selected different orders. The simulation and optical experimental results show that the influence of the zero-diffraction-order can be reduced, while keeping the good uniformity of the target images by this new approach.
