We report a switchable lens in which a twisted nematic (TN) liquid crystal cell is utilized to control the input polarization. Different polarization state leads to different path length in the proposed optical system, which in turn results in different focal length. This type of switchable lens has advantages in fast response time, low operation voltage, and inherently lower chromatic aberrati...

We propose a high dynamic range (HDR) liquid crystal display (LCD) with pixel-level local dimming. The device structure consists of a pixelated LCD dimming panel to control the backlight intensity entering the master LCD panel. According to our analysis and test cell experiment, this dual-panel display system possesses exceedingly high contrast ratio (> 1,000,000:1) and high bit-depth (> 14 bit...

introduction:surgeosight is a dedicated intra-operative hand-held gamma camera designed and manufactured by our team to be used for lymphoscintigraphy. although conventional gamma cameras are widely used, they lack the capability of the sentinel lymph node (sln) imaging in the operation room. like conventional gamma cameras it is necessary to calibrate surgeosight for linearity distortion, ener...

A pixel-level micropolarizer array bonded to a scientific camera has been developed for use in commercial dynamic interferometers. The pixelated array includes the 0, 45, 90, and, 135 degree polarization orientations. Micropolarizer arrays with elements as small as 7.4 microns and array sizes as large 4 Mega-pixels have been fabricated for use across the visible spectrum. The pixelated polariza...

Each of two detectors used in our Positron Emission Mammography (PEM) system consists of four 36 mm x 36 mm x 20 mm bismuth germanate (BGO) crystal detector blocks coupled to a crossed-wire anode position-sensitive photomultiplier tube (PS-PMT). To facilitate high spatial-resolution imaging, the crystal blocks have been finely pixelated using a diamond saw. In each detector, 36 x 36 1.9 mm x 1....

Conventional cameras rely upon a pixelated sensor to provide spatial resolution. An alternative approach replaces the sensor with a pixelated transmission mask encoded with a series of binary patterns. Combining knowledge of the series of patterns and the associated filtered intensities, measured by single-pixel detectors, allows an image to be deduced through data inversion. In this work we ex...

A positron emission mammograph (PEM) is an organ dedicated positron emission tomography (PET) scanner for breast cancer detection. State-of-the-art PEMs employing scintillating crystals as detection medium can provide metabolic images of the breast with significantly higher sensitivity and specificity with respect to standard whole body PET scanners. Over the past few years, crystal PEMs have d...