How optic fibers are manufactured?

How does a large glass cylinder become a tiny thread of ﬂ exible glass?

The tiny ﬁlament of glass at the core of a length of optical fiber starts out as two tubes. These tubes are made from fused quartz glass, which is mainly silica to give it ﬂexible properties. First the glass tubes are dipped in corrosive hydroﬂuoric acid to remove any oily residues, they are then placed in a pair of lathes that spin and heat both tubes with a hydrogen and oxygen ﬂame. When the tubes turn white they are nearing peak temperature and at 2,000°C the tubes melt together to form one longer tube.

This longer tube is placed in another lathe where it is turned and heated by a burner before being injected with chemical gases containing liquid forms of silicon and germanium. The heat and gases cause a chemical reaction that leaves a ﬁne white soot inside the tube. As the burner travels up and down the length of the tube the soot fuses to create a solid glass core. The outer glass tube will form the cladding around the core.

Heating softens the tube and the new glass inside until the tube collapses in on itself. You now have a solid rod called a preform. To thin the preform, it is placed vertically in a drawing tower. This heats one end of the rod to 2,000°C until the glass becomes a honey-like consistency. As the glass melts it stretches under its own weight and becomes a very tall, thin glass fiber.

Pulleys and lasers are used to measure the precise tension and diameter of the ﬁbre, which should be just 125 micrometres thick. The ﬁbre is then passed under an ultraviolet lamp to bake on a protective outer jacket. The ﬁnished optical ﬁbre is then rolled onto massive drums.

Comments

How Energy conversion from coal is done?

Single generator sets of over 600 MW are now used in the UK, though there are many smaller generators in use. A 600 MW generator can supplythe average needs of over 1 million UK households. Three or four such generators are typically installed in a single large coal-fired station which isoften sited close to a coal mine, away from the city dwellers who consume the electricity. Such generators are usually driven by a compound arrangement of highpressure, intermediate-pressure and low-pressure turbines, increasing in size as the pressure decreases. Modern turbines rotate in a speed range from 1500 to 3500 r.p.m., usually 3000 r.p.m. for the UK’s 50 Hz system. For large coal-fired plant the steam pressure could be 25 megapascals (MPa) with steam temperatures of 500–600 °C to improve the thermodynamic efficiency. In nuclear reactors, which operate under less demanding conditions, the steam is superheated to about 5 MPa and 300 °C. Modern water tube boilers are complex and have ...

All about Electronics & Instrumentation Engineering)(EI)

Vision : To be globally recognized as a seat of learning and innovation in Electronics for application to Communication, Transportation, Defence, Industry, Health Care, Entertainment, and many other consumer products. Mission : 1). To produce quality engineers in the field of Electronics and related domains. 2) To conduct research and develop products in the fields of Chip design, Communication Systems, Electronics Instrumentation, Signal Processing and other related areas with strong emphasis on critical state of the art applications. 3) To grow in the area of Design and Manufacturing of chips, boards and systems. Program Educational Objectives : I. To provide students a successful career in industry that meets the needs of national and multinational companies. II. To develop the ability among students to synthesize data and technical concepts for application to electronic product design and to solve real...

5 TOP FACTS LIGHTHOUSES

1 The builder of the Lighthouse of Alexandria, Sostratus – disobeying orders from the pharaoh Ptolemy – engraved his name and a dedication to the sea gods on the tower base. Fame 2 The technical term for the study of lighthouses is ‘pharology’, a word derived from Pharos, the island upon which the great Lighthouse of Alexandria once stood. Academia 3 George Meade built many notable lighthouses in the US during the classical lighthouse period. He is remembered in history as the winning general in the Battle of Gettysburg. War 4 The tallest lighthouse in the world is the Yokohama Marine Tower in Yokohama, Japan. The structure ﬂ ashes alternately green and red every 20 seconds. Tallest 5 Originally lighthouses were lit merely with open ﬁ res, only later progressing through candles, lanterns and electric lights. Lanterns tended to use whale oil as fuel.

Knowledge N Fact4u

Search This Blog