Lasers: A 40-year perspective

The evolution of lasers over the past 40 years from their initial usage for not so high-tech applications to establishing a large volume market for single applications is reviewed. Their applications in material and information processing, medicine, fibre optic communications have aided significant developments. The deployment of wavelength division multiplexing to expand the capacity of fibre transmission systems is also discussed. Laser-based optical communication systems are expected to fulfill the needs of fast access and high bandwidth portable communication devices for the next two decades.