MUCH PROGRESS has been made in the field of semiconductor laser and it is a matter of time when high quality devices approaching state of the art under laboratory conditions would be produced enmasse in the country, opined Dr B M Arora of department of Condensed Matter Physics and Material Sciences at Tata Institute of Fundamental Research (TIFR).
He was delivering the keynote address at the inauguration of a three-day National Laser Symposium (NLS-VI) at Raja Ramanna Centre for Advanced technology (RRCAT) on Tuesday.
Dr Arora speaking on ‘progress in semiconductor diode lasers’ said they have come a long way since their invention in 1962 from simple p-n junction devices operable pulsed at cryogenic temperature to the complex structures of today. These modern devices are capable of delivering more than 10 W CW power as arrays.
Early breakthrough in the chain development of the diode lasers was the emergence of double heterostructure for lowering threshold current density by optical confinement and carrier confinement.
These modern compact sources have long life and are preferred to all other types of lasers wherever they can meet the requirements.
Their uses now encompass communications, information storage, industrial materials processing, environment monitoring, medicine, diagnostics, spectroscopy, basic research and defense. The uses have now transcended almost all spheres of life and though they may be notorious for Star Wars and other defense applications they are more often used for human betterment.
Introduction of quantum well as a separate confinement layer for the carriers opened up a whole new vista, providing freedom of choice in the selection of material of the active layer and for band structure engineering.
Five groups in the country have reached the stage of synthesizing materials and fabricating devices of high wavelengths and substrates. He gave an overview of the current status of developments in diode lasers giving indication of the direction expected to emerge in this field in the near future.
RRCAT Director Dr VC Sahni welcomed the guests and gave a brief introduction of the centre along with nature of activities taking place. He outlined the work on INDUS-I and INDUS-II lasers as a major achievement and shared information on the atomic accelerator project, while speaking about the world scenario in lasers.
NLS-VI Convenor U Nundy said that there are a total of about 500 participants including about 260 from all over the country and about 20 from around the world. The NLS-VI organised at RRCAT in collaboration with Indian Laser Association is sponsored by Board of Research in Nuclear Sciences (BRNS).
The main attraction amongst the latter part of speeches was the plenary address by NCRA, Pune Professor Govind Swarup on ‘new challenges in the fields of science and technology in India: lessons from Giant Meterwave Radio Telescope (GMRT) technology’.
An exhibition on lasers participated by private sector was also inaugurated.