Dr Rajiv Desai
An Educational Blog
Undersea Optical Fiber Cable
Undersea Optical Fiber Cable: Figure above shows map of the world’s undersea communication cables. _ Section-1 Prologue: If you ask any average citizen, “where does the internet come from?” the answer you most likely get would be from space, via satellites. Wrong. Modern consumers have come to imagine the internet as something unseen in the atmosphere – an invisible “cloud” just above our heads, raining data down upon us. Because our devices aren’t tethered to any cables, many of us believe the whole thing is wireless but the reality is far more extraordinary. The vast majority of information that flows across the tens of billions of devices connected to the internet comes from the sea. Around 600 fiber-optic undersea cables carry more than 95% of all internet data. The fact that we route internet traffic through the ocean – amidst deep sea creatures and hydrothermal vents – […]
HOLOGRAM
HOLOGRAM: _____ Typical laser-lit transmission hologram ____ Prologue: Suppose you want to take a photograph of an apple. You hold a camera in front of it and, when you press the shutter button to take your picture, the camera lens opens briefly and lets light through to hit the film (in an old-fashioned camera) or the light-sensitive CCD chip (in a digital camera). All the light traveling from the apple comes from a single direction and enters a single lens, so the camera can record only a two-dimensional pattern of light, dark, and color. To be more accurate camera records wave length (color) and intensity (amplitude) of light waves. If you move your head slightly, the photograph remains same i.e. it is two dimensional. The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) […]
