121,426 research outputs found
Effect of mask discretization on performance of silicon arrayed waveguide gratings
We studied the impact of the lithography mask discretization on silicon arrayed waveguide grating (AWG) performance. When we decreased the mask grid from 5 to 1 nm, we observed an experimental improvement in crosstalk of 2.7-6 dB and cumulative crosstalk improvement of 1.2-5 dB, depending on the wavelength channel spacing and the number of output channels. We demonstrate the effect for the AWGs with 200-and 400-GHz channel spacing, with 4, 8, and 16 output wavelength channels. With 1-nm mask grid, the average crosstalk is -26 and -23 dB for 400- and 200-GHz devices, respectively. This is the lowest crosstalk for silicon AWGs reported to the best of our knowledge. A simulation study is performed by looking specifically at phase errors due to mask grid snapping (ignoring other phase error sources), which shows an expected improvement in crosstalk of 12 dB
Quantitative analysis of pixel crosstalk in AMOLED displays
The resolution of organic light-emitting diode (OLED) displays is increasing steadily as these displays are adopted for mobile and virtual reality (VR) devices. This leads to a stronger pixel crosstalk effect, where the neighbors of active pixels unintentionally emit light due to a lateral electric current between the pixels. Recently, the crosstalk was quantified by measuring the current flowing through the common hole transport layer between the neighboring pixels and comparing it to the current through the active pixel diode. The measurements showed that the crosstalk is more crucial for low light levels. In such cases, the intended and parasitic currents are similar. The simulations performed in this study validated these measurement results. By simulations, we quantify the crosstalk current through the diode. The luminous intensity can be calculated with the measured current efficiency of the diodes. For low light levels, the unintended luminance can reach up to 40% of the intended luminance. The luminance due to pixel crosstalk is perceivable by humans. This effect should be considered for OLED displays with resolutions higher than 300 PPI
Characterization of color cross-talk of CCD detectors and its influence in multispectral quantitative phase imaging
Multi-spectral quantitative phase imaging (QPI) is an emerging imaging
modality for wavelength dependent studies of several biological and industrial
specimens. Simultaneous multi-spectral QPI is generally performed with color
CCD cameras. However, color CCD cameras are suffered from the color crosstalk
issue, which needed to be explored. Here, we present a new approach for
accurately measuring the color crosstalk of 2D area detectors, without needing
prior information about camera specifications. Color crosstalk of two different
cameras commonly used in QPI, single chip CCD (1-CCD) and three chip CCD
(3-CCD), is systematically studied and compared using compact interference
microscopy. The influence of color crosstalk on the fringe width and the
visibility of the monochromatic constituents corresponding to three color
channels of white light interferogram are studied both through simulations and
experiments. It is observed that presence of color crosstalk changes the fringe
width and visibility over the imaging field of view. This leads to an unwanted
non-uniform background error in the multi-spectral phase imaging of the
specimens. It is demonstrated that the color crosstalk of the detector is the
key limiting factor for phase measurement accuracy of simultaneous
multi-spectral QPI systems.Comment: 16 pages, 8 figure
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