Check your understanding

Exercise 1. Read the text and answer the questions.

1. What types of lasers can you name?

2. What are the most common solid laser media?

3. What are common uses for semiconductor lasers?

4. Where are liquid lasers used?

5. What is the most important area of chemical lasers applications?

6. What are the advantages of free-electron lasers?

Exercise 2. Complete the sentences.

1. Solid-state lasers offer … . They are usually operated in a pulsed manner…

2. The laser medium of a gas laser can be …

3. The helium neon laser is known for its high frequency stability, …

4. Gallium arsenide is …

5. … were first developed in 1977 and are now becoming important research instruments.

6. The active medium of the liquid lasers consists of …

7. A chemical laser is usually defined as one …

Exercise 3. True or false?

1. The laser medium of a gas laser can be a pure gas, a mixture of gases or even metal vapour.

2. Solid state lasers offer the lowest power output.

3. Liquid lasers have the active medium consisting of solutions of organic dyes compounds in liquid solvents.

4. Chemical lasers don’t involve a chemical reaction between gaseous elements.