The three most important light sources to impact human life in the 21^st century will be sunlight, LEDs and lasers, said Professor Puspendu Das, Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore.

Speaking at The UN International Year of Light 2015 celebration event organized by The School of Physical Sciences of Periyar University to raise global awareness on lighting technologies, Das highlighted some advanced lighting technologies in 21^st century.

He noted in recent years the solar photovoltaic process mainly involving the conversion of sunlight into electric energy through different semiconductors.

With oil and petroleum resources drying up, solar energy has become the only clean energy alternative to meet future generations energy demands.

LEDs are also being used to illuminate the world through various applications, and also capable of creating high resolution display screens for smartphones, computers and televisions.

Fluorescent tube lights are being rapidly replaced by LEDs, and even HD LCD screens are also mostly comprised of white LEDs.

After the invention of the laser in 1960, it spurred the development of new science and engineering branches.

Laser technology has made possible advancements in nonlinear optics, holography, precision cutting, welding and drilling, laser-guided defense equipment, and optical telecommunication and laser-based surgical appliances.

Our world has been made very small through optical telecommunication. Raman spectroscopy would have become obsolete without lasers.