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Personal electronic devices such as cell phones and tablets continue to decrease in size while the number of features and add-ons keep increasing. One particular feature of great interest is an integrated projector system. Laser pico-projectors have been considered, but the technology has not been developed enough to warrant integration. With new advancements in diode technology and MEMS devices, laser-based projection is currently being advanced for pico-projectors. A primary problem encountered when using a pico-projector is coherent interference known as speckle. Laser speckle can lead to eye irritation and headaches after prolonged viewing. Diffractive optical elements known as diffusers have been examined as a means to lower speckle contrast. This paper presents a binary diffuser known as a Hadamard matrix diffuser. Using two static in-line Hadamard diffusers eliminates the need for rotation or vibration of the diffuser for temporal averaging. Two Hadamard diffusers were fabricated and contrast values measured showing good agreement with theory and simulated values.

<p class="MsoNormal" style="text-align:justify;"> <span lang="EN-US">Diffractive diffusers (phase gratings) are routinely used for homogenizing and beam shaping for laser beam applications. Another use for diffractive diffusers is in the reduction of speckle for pico-projection systems. While diffusers are unable to completely eliminate speckle they can be utilized to decrease the resultant contrast to provide a more visually acceptable image. Research has been conducted to quantify and measure the diffusers overall ability in speckle reduction. A theoretical Fourier optics model is used to provide the diffuser’s stationary and in-motion performance in terms of the resultant contrast level. Contrast measurements of two diffractive diffusers are calculated theoretically and compared with experimental results. Having a working theoretical model to accurately predict the performance of the diffractive diffuser allows for the verification of new diffuser designs specifically for pico-projection system applications.</span> </p>

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Supplement, 100th Annual Meeting Display EPosters PURPOSE: For coverage of extremity wounds, traditional subfascial profunda artery perforator (PAP) flap harvest results in a flap which is too thick. The aim of this study was firstly to characterize the suprafascial perforator anatomy of profunda artery perforators on preoperative computed tomography angiography (CTA) and secondly to describe our approach and experience with the superthin PAP flap for extremity reconstruction.METHODS: Suprafascial profunda artery perforator anatomy was reviewed in CTAs in 159 thighs. We describe our experience with superthin PAP flaps using a single dominant perforator, for extremity reconstruction in 20 consecutive patients. RESULTS:Two main perforator patterns, a "T" (superficial bifurcation) and "Y" (deeper bifurcation) were identified. The ratio between the total skin thickness and the distance from the skin to the perforator bifurcation point and the total skin thickness was higher in the "T" perforator pattern. A dominant "T" perforator (n=97) was more common than "Y" (n=62). A dominant "T" perforator was more common in women and with higher body mass index (BMI). In the clinical study, we found an almost perfect correlation between skin thickness of the bifurcation point of a dominant "T" perforator and thickness of the superficial fascia where a superthin PAP flap is elevated. CONCLUSION:A dominant "T" perforator on preoperative CTA accurately predicts thickness of a PAP flap elevated at the level of the superficial fascia.