How do fiber optic cables work?

Fiber optics (optical fibers) are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances.

If you look closely at a single optical fiber, you will see that it has the following parts:

• Core - Thin glass center of the fiber where the light travels 
•  Cladding - Outer optical material surrounding the core that reflects the light back into the core
• Buffer coating - Plastic coating that protects the fiber from damage and moisture

Hundreds or thousands of these optical fibers are arranged in bundles in optical cables. The bundles are protected by the cable's outer covering, called a jacket.

• Optical fibers come in two types:
• Single-mode fibers
•  Multi-mode fibers

Single-mode fibers have small cores (about 3.5 x 10-4 inches or 9 microns in diameter) and transmit infrared laser light (wavelength = 1,300 to 1,550 nanometers). Multi-mode fibers have larger cores (about 2.5 x 10-3 inches or 62.5 microns in diameter) and transmit infrared light (wavelength = 850 to 1,300 nm) from light-emitting diodes (LEDs).

Some optical fibers can be made from plastic. These fibers have a large core (0.04 inches or 1 mm diameter) and transmit visible red light (wavelength = 650 nm) from LEDs.

How Does an Optical Fiber Transmit Light?

Suppose you want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway -- light travels in straight lines, so it is no problem. What if the hallway has a bend in it? You could place a mirror at the bend to reflect the light beam around the corner. What if the hallway is very winding with multiple bends? You might line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber.

The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances.

However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light (for example, 850 nm = 60 to 75 percent/km; 1,300 nm = 50 to 60 percent/km; 1,550 nm is greater than 50 percent/km). Some premium optical fibers show much less signal degradation -- less than 10 percent/km at 1,550 nm.

Advantages of Fiber Optics

Why are fiber-optic systems revolutionizing telecommunications? Compared to conventional metal wire (copper wire), optical fibers are:

Less expensive - Several miles of optical cable can be made cheaper than equivalent lengths of copper wire. This saves your provider (cable TV, Internet) and you money. Thinner - Optical fibers can be drawn to smaller diameters than copper wire. Higher carrying capacity - Because optical fibers are thinner than copper wires, more fibers can be bundled into a given-diameter cable than copper wires. This allows more phone lines to go over the same cable or more channels to come through the cable into your cable TV box.Less signal degradation - The loss of signal in optical fiber is less than in copper wire. Light signals - Unlike electrical signals in copper wires, light signals from one fiber do not interfere with those of other fibers in the same cable. This means clearer phone conversations or TV reception. Low power - Because signals in optical fibers degrade less, lower-power transmitters can be used instead of the high-voltage electrical transmitters needed for copper wires. Again, this saves your provider and you money. Digital signals - Optical fibers are ideally suited for carrying digital information, which is especially useful in computer networks. Non-flammable - Because no electricity is passed through optical fibers, there is no fire hazard.Lightweight - An optical cable weighs less than a comparable copper wire cable. Fiber-optic cables take up less space in the ground. Flexible - Because fiber optics are so flexible and can transmit and receive light, they are used in many flexible digital cameras for the following purposes:

• Medical imaging - in bronchoscopes, endoscopes, laparoscopes
• Mechanical imaging - inspecting mechanical welds in pipes and engines (in airplanes, rockets, space shuttles, cars)
•  Plumbing - to inspect sewer lines

Because of these advantages, you see fiber optics in many industries, most notably telecommunications and computer networks. For example, if you telephone Europe from the United States (or vice versa) and the signal is bounced off a communications satellite, you often hear an echo on the line. But with transatlantic fiber-optic cables, you have a direct connection with no echoes.

Visit Us : @ Hyperjet

Read More

The Future of Green Technology

So you've heard of green buildings, green businesses, green products, and green living, but have you ever heard of green technology? If you have, are you clear on what exactly makes technology “green”?

We've come across a lot of people who had similar questions about “Green Technology”: what it is, what it's used for and if you're just now using it without even knowing!

Skipping the complicated scientific definitions, green technology is simply any technology that is more efficient and environmentally friendly. If you're not sure what that means, one example is a printer that uses less energy and ink for printing but still gives you the results you're looking for. That's green technology- it's both efficient and environmentally friendly! 

Green technology grew out of the 1960's and 70's as a response to increased prices of oil, and the widespread realization that fossil fuels could be running out soon. The sustainability movement and green technology soon became intertwined as a way to not only insure a cleaner world for tomorrow, but also the idea of a civilization that was self-sustaining, and not environmentally draining.

Contrary to popular belief, green tech isn't just about wind turbines, solar panels and alternative fuel, but rather the areas of its application extend to building construction, sustainable purchasing, and even green chemistry. Below are some remarkable green tech examples:

1. Solar Spray
   
   Solar panels are used to turn sun rays into energy, but they’re often expensive, bulky and are not particularly attractive. In comes the amazing solar spray! Developed by a Norwegian company called EnSol AS, once sprayed over your ordinary windows it turns them into solar panels that convert sun rays into watts you can use to power your home. The best part? The spray is transparent!
    
2. The Power of Footsteps
   
   When considering alternative energy sources, companies usually look to sun and wind power, but Power leap decides to do just the opposite of that. Their alternative idea uses inside energy generated by human foot traffic to harness energy. Train stations, sidewalks, public parks are all great examples of places this technology can be applied. 

3. Science City heating system
   
   In many parts of the world, a significant amount of energy is used to cool homes in summer, and just as much is used to hear those homes in winter. In Switzerland, Science City, part of the ETH Zurich campus, has developed a pioneering system that stores the heat of the summer underground, only to pump it back up to heat the homes during winters- talk about thinking outside the box. 

These aren't just ideas, they're actually projects in the making, and what’s even more amazing is that these just scratch the surface. Will we be seeing flying cars in the near future too? But one thing is for sure: future technology is looking a lot greener.

See More : @ Hyperjet

Read More