1960 is generally seen as the birth year of birth of the laser. T.H.Maiman pumped a ruby bar, whose two parallel faces served as a resonator, with a pulsed flashbulb, thereby realising for the first time a coherent radiation source emitting in the visible spectral range. Maiman's work marked a turning point in quantum electronics: on the one hand, it brought many years of theoretical and practical effort to create such a light source to fruition, on the other hand it initiated a phase of rapid scientific-technical development that still continues today.

The end the fifties saw the race for the "optical maser" (as the laser was still called then) hotting up. In 1958, Schawlow and Townes had theoretically demonstrated the possibility to create an amplifier for radiation for the visible and infrared spectral range, similar to the ones that had already been suggest in 1951 and built in 1954 for microwaves. As early as 1959, G.Gould outlined the design principle for such a device, had the sketches recorded by a notary and later applied for a patent for his ideas. He also coined the phrase "Light Amplifier by Stimulated Emission of Radiation", i.e. LASER. He is therefore regarded by some as the "inverntor of the laser".

Yet like so often in scientific endeavour, one man had the ingenious intuition and the necessary portion of luck, compared with his predecessors and competitors: His name was Maiman. Maiman used ruby - which, due to its allegedly low radiation efficiency was seen as showing little promise as an active medium for a laser - and succeeded. In the race for the first laser, with a relatively modest budget from Hughes Research, he, the outsider, beat all the research groups which formed the "Scientific Community" in this field at the time: Lincoln Labs, IBM, Siemens, RCA Labs, GE, Bell Labs, TRG and many others. His results where, however, so surprisingly unusual, that their publication in the prestigious "Physical Review Letters" was refused. (In hindsight, the reviewers must have been rather embarrassed!) Maiman therefore took a route that was rather unusual for an American and published his results in the English magazine "Nature". On 7 July 1960, Hughes Research held a press conference announcing the invention of the laser. With his results, Maiman initiated hitherto scarcely imaginable developments in applied physics. Laser technology began its triumphant progress.

But here to, like so often in science, Maiman missed out on the biggest scientific recognition of them all, the Nobel prize. His predecessors Basov, Prokhorov and Townes received the prize in 1964 for their "fundamental work in quantum electronics that lead to the construction of oscillators and amplifiers based on the maser-laser principle". Schwalow received the prize in 1981 for his contributions to laser spectroscopy.

Maiman was left empty-handed, despite the fact that few other inventions came so close to Nobel's original intentions as the laser. Ingeniously simple, practically oriented constructions, especially if they come from an outsider, are sometimes seen in academic circles as lucky coincidence and therefore often receive less respect than they deserve. And yet it is often the simple that is so hard to produce.

The following sections provide a chronology of the laser development. Due to their diversity and complexity, laser applications have been excluded. Neither was quantitative progress recorded. Only new principles, concepts and laser types, as well as qualitative breakthroughs are mentioned. Also, developments often occured in parallel, making it difficult to prioritise. Against this background, we cannot claim completeness of our list.

This chronology can demonstrate to the laser user how much time has to pass, even in our fast-moving, innovation-oriented society, for an idea to progress from first implementation in the laboratory to large-scale practical application. This is highlighted by the example of semiconductor lasers, which have been used as a mass product in optical communication systems and CD players only since the early eighties. They had been proposed as early as 1959 (even before Maiman's first laser demonstration!), were first realised in 1962 (at low temperatures and in pulse mode), and continuously operated (still with cooling) a year later. Only the suggestions in 1963 by Kroemer, and also Alferov and Kazarinov, for a double-hetero structure opened the way for a more efficient emission. Pulsed-mode operation was thus achieved for the first time in 1968, and in May 1970 Alferov's team was able to present the first laser diode that continuously operated at room temperature in Leningrad. A month later, the (western) parallel development was presented by Hayashi, Panish and others. But laser diodes were still far from ready for practical application. A large number of steps were still required to elevate semiconductor lasers to current technological levels: New growing methods, new materials (e.g. InGaAsP, 1976), new structures (e.g. quantum wells, 1978), new principles (e.g. surface-emitting diodes, 1979), new wavelengths (e.g. blue spectral range, 1991 and 1996) and many others.

But apart from the commercial success of the semiconductor laser, last year also saw a suitably worthy scientific accolade for one of its fathers: Nearly forty years after he developed the concept of hetero structures and thirty years after he first developed laser diodes that operated continuously at room temperature, the Russian Zh.I.Alferov received the Nobel prize for physics.

Only the future will tell which of the current and fundamentally new laser developments will achieve economic significance (be it atom lasers, lasers based on polymers, porous semiconductor structures or others).

Year
- Theory, propositions and conception (-> Year of continuation or implementation)
- Experiments and realisation (-> Year of continuation or theoretical description)