Check your understanding Exercise 1. Answer the following questions.

1. What is known about the invention of the optical telegraph?

2. Why didn’t Bell’s optical telephone system find wide application?

3. How did the invention of laser affect optical communications?

4. What goal did Heinrich Lamm set working on image transmission through optical fibers?

5. What were the results of the experiments with fused silica?

Exercise 2.Topics for discussion.

1. Why do you think the development of fiber optics took such a long time?

2. Why is it possible to call the development of fiber optics a key for world's communications?