ABSTRACT
Laser technology is one of the most rapidly developing areas in modern technology. This chapter has two experimental sections. One section involves learning how to direct a laser beam in space using different techniques. In the second section, presents practical applications of laser-beam expansion by building a Galilean telescope and a Keplerian telescope. These sections would present the theory applications, alignment process and hands-on experience. The chapter then describes the lasing medium. Depending on the particular lasing material, specific wavelengths of light are absorbed and specific wavelengths are emitted. As a result, laser beams are very different from normal light. Laser beams have the following properties: 1. Laser light is monochromatic; 2. Laser light is coherent; and 3. Laser light is very directional and has a tight concentrated beam. Laser beams are used to produce signals for fibre-optic telecommunication systems and also industrial, medical, military, micro-machining and so on.
