Optical fibres are extensively used in telecommunications to transmit signals of low intensity, high frequency over very long distances. Optical fibres have high quality, absorb very little light energy, and are effective. They use the phenomenon of total internal reflection for transmission of light by multiple reflections.
1. Transmission of electrical (electronic, in terms of milli volts/milli amps) signals
They are not affected by electromagnetic interference from outside. So they are a good choice in small and crowded high frequency circuits. As the bandwidth is very high, millions of communications share the same fibre. Extensively used in engineering.
2. Transmission optical signals - they are used in specialized circuits.
3. Decorative lamps. These are very common, with beautiful symmetric patterns of light. A small bulb is kept at one end of a strand. The other end is kept open forming fountain like structure or any other shape. They are good gift articles.
4. They are used to see pictures and take photographs of internal parts inside the body - stomach, esophagus, and even the intestines. They can be inserted in narrow locations to be able to transmit/receive light through them and see what is happening in small unreachable locations. So they are useful for the doctors.