In this study, we propose a holographic augmented reality (AR) display with a wide viewing zone realized by using a special-designed reflective optical element. A conical holographic optical element (HOE) is used as s...In this study, we propose a holographic augmented reality (AR) display with a wide viewing zone realized by using a special-designed reflective optical element. A conical holographic optical element (HOE) is used as such a reflective optical element. This conical HOE was implemented to reconstruct a diverging spherical wave with a wide spread angle. It has a sharp wavelength selectivity by recording it as a volume hologram, enabling augmented reality (AR) representation of real and virtual 3D objects. The quality of the generated spherical wave and the spectral reflectivity of the fabricated conical HOE were investigated. An optical superimposition between real and virtual 3D objects was demonstrated, thereby enhancing the validity of our proposed method. A horizontal viewing zone of 140° and a vertical viewing zone of 30° were experimentally confirmed. The fabrication procedure for the conical HOE is presented, and the calculation method of the computer-generated hologram (CGH) based on Fermat’s principle is explained in detail.展开更多
A novel scheme is proposed, in which the aberrations in the off-axis holographic lenses used as demultiplexers are reduced to a low enough level for relatively small channel spacing. The scheme includes optimizing the...A novel scheme is proposed, in which the aberrations in the off-axis holographic lenses used as demultiplexers are reduced to a low enough level for relatively small channel spacing. The scheme includes optimizing the recording and reconstruction geometries and collimating the reconstruction wave with a gradient-index lens. A demultiplexer operated in the 1 550-nm band with 5-nm channel spacing and -∞-dB crosstalk is obtained using the scheme. The channel spacing can be decreased to 2 nm by etching the cladding of the output fibers to a smaller size.展开更多
Amorphous bulk composites were prepared by doping azo-dye disperse red 1 （DR1） in poly（methyl methacrylate） （PMMA） matrices. Photoinduced anisotropy of such kind of bulk polymer material was investigated experim...Amorphous bulk composites were prepared by doping azo-dye disperse red 1 （DR1） in poly（methyl methacrylate） （PMMA） matrices. Photoinduced anisotropy of such kind of bulk polymer material was investigated experimentally by measuring the dichroism when irradiating with linearly polarized green light with different polarization direction. With the interaction of bi-photonic beams at 514 and 632.8 nm, transient gratings in the bulk composites could be established, which was a kind of population gratings of trans and cis DR1 isomers and was attributed to the weak absorption of cis isomers at 632.8 nm and the positive dichroism of trans isomers at 514 nm. Furthermore, the all-optical switching behavior of the transient holographic gratings was observed repeatedly by turning on and off the writing beams and a response time of ten milliseconds order could be obtained.展开更多
文摘In this study, we propose a holographic augmented reality (AR) display with a wide viewing zone realized by using a special-designed reflective optical element. A conical holographic optical element (HOE) is used as such a reflective optical element. This conical HOE was implemented to reconstruct a diverging spherical wave with a wide spread angle. It has a sharp wavelength selectivity by recording it as a volume hologram, enabling augmented reality (AR) representation of real and virtual 3D objects. The quality of the generated spherical wave and the spectral reflectivity of the fabricated conical HOE were investigated. An optical superimposition between real and virtual 3D objects was demonstrated, thereby enhancing the validity of our proposed method. A horizontal viewing zone of 140° and a vertical viewing zone of 30° were experimentally confirmed. The fabrication procedure for the conical HOE is presented, and the calculation method of the computer-generated hologram (CGH) based on Fermat’s principle is explained in detail.
基金supported by the "985" Project of Xiamen University and the National Natural Science Foundation of China (No. 50802080)
文摘A novel scheme is proposed, in which the aberrations in the off-axis holographic lenses used as demultiplexers are reduced to a low enough level for relatively small channel spacing. The scheme includes optimizing the recording and reconstruction geometries and collimating the reconstruction wave with a gradient-index lens. A demultiplexer operated in the 1 550-nm band with 5-nm channel spacing and -∞-dB crosstalk is obtained using the scheme. The channel spacing can be decreased to 2 nm by etching the cladding of the output fibers to a smaller size.
文摘Amorphous bulk composites were prepared by doping azo-dye disperse red 1 （DR1） in poly（methyl methacrylate） （PMMA） matrices. Photoinduced anisotropy of such kind of bulk polymer material was investigated experimentally by measuring the dichroism when irradiating with linearly polarized green light with different polarization direction. With the interaction of bi-photonic beams at 514 and 632.8 nm, transient gratings in the bulk composites could be established, which was a kind of population gratings of trans and cis DR1 isomers and was attributed to the weak absorption of cis isomers at 632.8 nm and the positive dichroism of trans isomers at 514 nm. Furthermore, the all-optical switching behavior of the transient holographic gratings was observed repeatedly by turning on and off the writing beams and a response time of ten milliseconds order could be obtained.
