Lasers Basics, Advances and Applications

Abstract

Shortly after the realization of the first optically-pumped (ruby) laser, electrically-pumped lasing in the semiconductorSemiconductor laser gallium arsenide (GaAs) was reported by Robert N. Hall and others in 1962 using a diode structure. Initially, the operation was restricted to pulsed mode at low temperatures. With the invention of the double heterostructure (Sect. 10.3), continuous wave lasing at room temperature was achieved in 1970. Today, semiconductor diode lasers are of great economic importance and fabricated in large quantities, as they find numerous applications. Among other applications, they are employed in consumer goods such as CD, DVD and Blu-ray players, as well as in personal computers, laptops and laser printers. Besides, diode laser technology has become essential in telecommunication systems over the last decades, especially with the growth of the internet. Increasing interest is also emerging towards direct-diode applications in material processing like soldering and welding which is driven by the progressing development of high-power diode lasers. Furthermore, novel technologies like 3D printing in industry, medicine and architecture as well as 3D sensing and automotive lighting are expected to further increase the demand for semiconductor lasers.