Stereoscopy addresses depth perception loss in laparoscopy but encounters multiple design inefficiencies. A light field laparoscope is proposed to more effectively capture depth information. Experimental results demon...
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An effective design method of freeform micro lens array is presented for shaping varied laser beams into prescribed rectangular illumination. The variable separation mapping is applied to design concave freeform surfa...
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An effective design method of freeform micro lens array is presented for shaping varied laser beams into prescribed rectangular illumination. The variable separation mapping is applied to design concave freeform surfaces for constructing a freeform lens array. Several dedicated examples show that the designed freeform optical lens array can achieve a prescribed rectangular illumination pattern, especially without considering the initial states of incident laser beams. Both high collection efficiency and good spatial uniformity can be available simultaneously. Tolerance analysis is also performed to demonstrate that this optical device can well avoid fabricating difficulty in actual applications.
It has been a common problem in optical see-through head-mounteddisplays that the displayed image lacks brightness and contrast compared with the direct view of a real-world scene. This problem is aggravated in head-...
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It has been a common problem in optical see-through head-mounteddisplays that the displayed image lacks brightness and contrast compared with the direct view of a real-world scene. This problem is aggravated in head-mounted projection displays in which multiple beam splitting and low retroreflectance of a typical retroreflective projection screen yield low luminous transfer efficiency. To address this problem, we recently proposed a polarized head-mounted projection display (p-HMPd) design where the polarization states of the light are deliberately manipulated to maximize the luminous transfer efficiency. We report the design of a compact p-HMPd prototype system using a pair of high-resolution ferroelectric liquid-crystal-on-silicon (FLCOS) microdisplays. In addition to higher resolution, the FLCOS displays have much higher optical efficiency than a transmissive-type liquid crystal display (LCd) and help to further improve the overall light efficiency and image quality We detail the design of a compact illumination unit for the FLCOS microdisplay, also commonly referred to as the light engine, and a projection lens, both of which are key parts of the p-HMPdsystem. The performances of the light engine and projection lens are analyzed in detail. Finally, we present the design of a compact p-HMPd prototype using the custom-designed light engine and projection optics. (c) 2008 Optical Society of America.
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