Laser physics important dates in history
Important Steps Leading to the Discovery of the Laser:
1887: Heinrich Hertz accidentally discovers the photoelectric effect, setting the stage for Albert Einstein to introduce the concept of photons.
1901: Max Planck resolves the “ultraviolet catastrophe” by proposing that energy is quantized, leading to the idea of discrete energy levels represented by nhν.
1905: Albert Einstein quantifies electromagnetic energy with the introduction of the photon. He later connects photons to black body radiation through the concept of stimulated emission.
1949: Kastler and Brossel achieve the first optical pumping and population inversion, paving the way for the development of MASERs (Microwave Amplification by Stimulated Emission Radiation).
1954: The first MASER is constructed, operating in the microwave region using a confined electromagnetic wave.
1958: Schawlow and Townes propose using an open Fabry-Pérot cavity for laser experiments, allowing for amplification along a single dimension.
May 16, 1960: Theodore Maiman demonstrates the first optical laser using a pulsed ruby crystal, marking a significant milestone.
1961: Javan, Bennet, and Herriot develop the first continuous gas laser, the helium-neon laser, capable of emitting various wavelengths.
1962: The first red helium-neon laser is created.
1965: Semiconductor lasers are invented.
1966: Colored pulsed lasers, including red, orange, and yellow, are produced.
1970: Colored continuous-wave lasers become available, further advancing laser technology.
Since the inception of the first laser in 1960, continuous advancements have been made, particularly in solid-state lasers, aiming for shorter pulses and greater power.
why laser invented ?
The invention of the laser initially sparked grandiose expectations and extravagant ideas, envisioning it as a solution to numerous global challenges. However, these early hopes were largely impractical or premature, such as using lasers to melt icebergs, revolutionize telecommunications, or transport high voltages. Despite these ambitious notions, practical applications for the laser were initially scarce, leading many to question its utility.
Unlike many other 20th-century inventions that arose from pressing industrial, scientific, or societal needs, the laser seemed to emerge without a clear purpose. While renowned physicists like Townes, Schawlow, Basov, and Prokhorov laid the groundwork for the laser by exploring stimulated emission and transposing microwave amplifiers into the optical domain, there was no urgent demand for such a device.
Even Arthur Schawlow, a key figure in laser development, humorously suggested mundane uses like incorporating lasers into typewriters for erasing errors. The early years saw skepticism from both industrialists and scientists, with Pierre Aigran famously remarking, “We already have the solution; we just have to find the problem.”
However, over time, the laser found practical applications across a wide range of fields, from telecommunications and laser weapons to biomedical procedures and materials processing. What began as a seemingly impractical “toy” for researchers evolved into one of the most significant inventions of the 20th century, profoundly impacting physics and various industries. Today, lasers are indispensable tools utilized in diverse sectors, including materials treatment, medicine, precision instrumentation, and entertainment.
