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Cascade six-level phase-mask achromatic coronagraph
Applied Optics, 2016A cascade six-level phase-mask achromatic coronagraph is proposed. We show that, for the ideal aberration-free case, the average suppression of the central starlight in a three-stage six-level phase-mask achromatic coronagraph (SLPMC) can reach about 10⁻⁸ over a 40% bandwidth. We also do the optimization analysis of the working wavelength of each phase
Yajun, Ge +4 more
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Acousto-optic phase-mask emulation
Journal of Micro/Nanolithography, MEMS, and MOEMS, 2007Emulation of phase-shift mask (PSM) imaging techniques through the use of acousto-optic interaction, rather than fixed photomasks, is demonstrated. The phasefront and irradiance profile of a uniform illumination beam are manipulated acousto-optically in two dimensions by controlling the phase and amplitude of the radio-frequency (RF) signals, which ...
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Influence of interaural phase on forward masking
The Journal of the Acoustical Society of America, 1973This study investigated the degree to which masking level differences (MLDs) obtained by six normal-hearing subjects during simultaneous masking continue to be manifest during the forward masking that follows termination of the masker. Thresholds for 500-Hz probe tones of 745 msec were obtained in quiet and in a 1000-msec narrow-band noise centered at ...
J, Punch, R, Carhart
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Interaural Phase and the Release from Masking
International Journal of Audiology, 1972In previous presentations to this congress we have reported an increase in intelligibility of isolated words at poor signal-to-noise ratios when the phase angle differences between the ears were adjusted to certain values. Question has arisen as to whether this phenomenon is one of a peculiar property of speech or one of that kind usually called ...
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Broadband nulling of a vortex phase mask
Optics Letters, 2005A pulse transmitted through a helical vortex phase mask undergoes a temporal Hilbert transform. The fluence transmitted into the unfavorable plane wave mode is found to increase as the square of the bandwidth and, to first order, is independent of the topological charge.
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