We present theoretical and experimental results for the expected impact on high-throughput optical communication
systems of pulse broadening effects from scattered light propagating through water-based clouds. Existing analytical
models are compared with experimental results. A preferred Monte Carlo model is developed and validated from field
measurements of off-axis scattering through clouds, using a low-power continuous wave laser source at 1550 nm
wavelength. This model is used in the time domain to examine the effects of pulse broadening for Gigabit and higher
systems with practical apertures and fields of view. Results indicate that, for most current scenarios, pulse stretching
may not cause significant inter-symbol interference.
This paper describes Litton's time-multiplexed 3-D display technology, which allows groups of viewers to see full stereo with kineopsis (lookaround capability) without using any eye or head gear. We detail the construction of our latest 50'- screen prototype, which is brighter and has higher resolution than our 25'-prototype presented previously. The time- multiplexed concept allows the sequential projection of narrow strips of images into the viewer space and provides realistic movement parallax in a horizontal plane with full autostereoscopic images. The time-multiplexed nature allows full-screen resolution for each view and shared components for the optical trains. Our latest prototype, configured for entertainment applications, replaces our previous color sequential system with separate red, green, and blue CRTs for a brighter image [up to 120 foot-Lamberts (fL)] with much better color saturation. A new optical layout uses dichroics and beamsplitters to avoid the need for coatings with sharp cut-off frequencies, and a concave-mirror screen provides better image sharpness. We can also provide up to fifteen views in each eyebox without tube-abutment seams. Improved electronic performance provides capability of 30 frames-per- seconds interlaced at 640 by 480 pixel resolution. Special picture-shape correction circuitry has been added for a rectangular image-frame, despite a light path skewed out-of- plane.
We describe the development and construction of a large screen version of the Cambridge time-multiplexed autostereo display. The new device uses a 50 inch diagonal spherical mirror in place of the 10 inch Fresnel lens of the original Cambridge color display. A fivefold increase in image luminance has been achieved by the replacement of sequential color on a single CRT with separate red, green, and blue CRTs. Fifteen views are displayed at 640 X 480 (VGA) resolution with about 250 cd/m<SUP>2</SUP> luminance and 30 Hz interlaced refresh rate. A 22 mm interview separation provides three views between a typical viewer's eyes, giving a smooth stereoscopic effect over a 330 mm wide eye box. Two identical optical systems have been built, allowing simultaneous use of the device by two viewers. The two system are off-axis with respect to the main mirror, requiring geometric compensation on the CRTs in addition to the normal color convergence. The prototype produces two independent full color, large 3D images which can be viewed under normal lighting conditions.