INTRODUCTION
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term “LASER” originated as an acronym for “Light Amplification by Stimulated Emission of Radiation”. The first laser was built in 1960 by Theodore. H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow.
A laser differs from other sources of light in that it emits light coherently. Spatial coherence allows a laser to be a focused to a tight spot, enabling application such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances, enabling applications such as laser pointers and lidar.
Lasers are used in optical disk drives, laser printers barcode scanners, DNA sequencing instruments, fiber-optic and free–space optical communication, laser surgery and skin treatment, cutting and welding materials, military and law enforcement devices for marking targets and measuring range and speed, and laser lighting displays for entertainment. They have been used for car headlamps on luxury car, by using a blue laser and a phosphor to produce highly directional white light.
THE THREE NOBEL LAUREATES IN LASER
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term “LASER” originated as an acronym for “Light Amplification by Stimulated Emission of Radiation”. The first laser was built in 1960 by Theodore. H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow.
A laser differs from other sources of light in that it emits light coherently. Spatial coherence allows a laser to be a focused to a tight spot, enabling application such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances, enabling applications such as laser pointers and lidar.
Lasers are used in optical disk drives, laser printers barcode scanners, DNA sequencing instruments, fiber-optic and free–space optical communication, laser surgery and skin treatment, cutting and welding materials, military and law enforcement devices for marking targets and measuring range and speed, and laser lighting displays for entertainment. They have been used for car headlamps on luxury car, by using a blue laser and a phosphor to produce highly directional white light.
THE THREE NOBEL LAUREATES IN LASER
The 2018 Nobel prize in Physics on
October 2 ,2018 was awarded to Arthur Ashkin of USA , Gerard Mourou of France and Donna Strickland of Canada, making her the
third woman to receive the prestigious award. The trio of laureates won the
prize for groundbreaking inventions in the field of physics.
ARTHUR ASHKIN
ARTHUR ASHKIN
Arthur
Ashkin born on 2 September 1922, is an American Scientist and Nobel laureate who
worked at Bell laboratories and Lucent Technologies. Ashkin has been considered
by many as the father of optical tweezers, for which he was awarded the Nobel
Prize in Physics 2018 at the age of 96, becoming the oldest Nobel Laureate. He
resides in Rumson, New Jersey.
Ashkin started his work on manipulation of microparticles with laser light in the late 1960s which resulted in the invention of optical tweezers in 1986. He also pioneered the optical trapping process that eventually was used to manipulate atoms, molecules and biological cells. The key phenomenon is the radiation pressure of light; this pressure can be dissected down into optical gradient and scattering forces.
On October 2, 2018, Arthur Ashkin was awarded a Nobel Prize in Physics for his work on optical trapping sharing it with Donna Strickland and Gerard Mourou who received the other half of that year’s prize. Ashkin was honoured for his invention of optical tweezers that grab particles, atoms, viruses and other living cells with their laser beam fingers. With this he was able to use the radiation pressure of light to move physical objects, ‘an old dream of science fiction’, the Royal Swedish Academy of Sciences said.
At 96, he is the oldest Nobel Prize Laureate to be awarded the prize. Ashkin was awarded half of the prize while half was shared between Gerard Mourou and Donna Strickland for their work on Chirped-Pulse Amplification, a technique “now used in laser machining enables doctors to perform millions of corrective laser eye surgeries every year.”
Ashkin started his work on manipulation of microparticles with laser light in the late 1960s which resulted in the invention of optical tweezers in 1986. He also pioneered the optical trapping process that eventually was used to manipulate atoms, molecules and biological cells. The key phenomenon is the radiation pressure of light; this pressure can be dissected down into optical gradient and scattering forces.
On October 2, 2018, Arthur Ashkin was awarded a Nobel Prize in Physics for his work on optical trapping sharing it with Donna Strickland and Gerard Mourou who received the other half of that year’s prize. Ashkin was honoured for his invention of optical tweezers that grab particles, atoms, viruses and other living cells with their laser beam fingers. With this he was able to use the radiation pressure of light to move physical objects, ‘an old dream of science fiction’, the Royal Swedish Academy of Sciences said.
At 96, he is the oldest Nobel Prize Laureate to be awarded the prize. Ashkin was awarded half of the prize while half was shared between Gerard Mourou and Donna Strickland for their work on Chirped-Pulse Amplification, a technique “now used in laser machining enables doctors to perform millions of corrective laser eye surgeries every year.”
GERARD MOUROU
Gerard Albert Mourou born on 22 June
1944, is a French Scientist and pioneer in the field of Electrical Engineering and Lasers. He was awarded a Nobel Prize in Physics in 2018, along with the Donna
Strickland, for the invention of Chirped-Pulse Amplification, a technique later
used to create ultrashort pulse, very high intensity laser pulses.
In 1994, Mourou and his team at the University of Michigan discovered that the balance between the self-focusing refraction and self-attenuating diffraction by ionisation and rarefaction of a laser beam of terawatt intensities in the atmosphere creates “Filaments” which act as waveguides for the beam thus preventing divergence.
Mourou and Strickland found that stretching a laser out reduced its peak power, which could then be greatly amplified using normal instruments. It could then be compressed to create the short lived, highly powerful lasers they were after. The technique, which was described in Strickland’s first scientific publication, came to known as Chirped Pulse Amplification (CPA). They were probably unaware at the time that tools would make it possible to study natural phenomenon in unprecedented ways. CPA could also per definition be used to create a laser pulse that only lasts one attosecond, one billionth of a billionth of second. At those timescales, it became possible not only to study chemical reactions, but what happens inside individual atoms.
The Guardian and Scientific American Provided Simplified Summaries of the work of Strickland and Mourou: it “paved the way for the shortest, most intense laser beams ever created”. “The ultrabrief, ultrasharp beams can be used to make extremely precise cuts so their technique is now used in laser machining and enables doctors to perform millions of corrective” laser eye surgeries. Canadian Prime Minister Justin Trudeu acknowledge the achievements of Mourou and Strickland: “Their innovative work can be found in applications including corrective eye surgery, and is expected to have a significant impact on cancer therapy and other physics research in the future.”
In 1994, Mourou and his team at the University of Michigan discovered that the balance between the self-focusing refraction and self-attenuating diffraction by ionisation and rarefaction of a laser beam of terawatt intensities in the atmosphere creates “Filaments” which act as waveguides for the beam thus preventing divergence.
Mourou and Strickland found that stretching a laser out reduced its peak power, which could then be greatly amplified using normal instruments. It could then be compressed to create the short lived, highly powerful lasers they were after. The technique, which was described in Strickland’s first scientific publication, came to known as Chirped Pulse Amplification (CPA). They were probably unaware at the time that tools would make it possible to study natural phenomenon in unprecedented ways. CPA could also per definition be used to create a laser pulse that only lasts one attosecond, one billionth of a billionth of second. At those timescales, it became possible not only to study chemical reactions, but what happens inside individual atoms.
The Guardian and Scientific American Provided Simplified Summaries of the work of Strickland and Mourou: it “paved the way for the shortest, most intense laser beams ever created”. “The ultrabrief, ultrasharp beams can be used to make extremely precise cuts so their technique is now used in laser machining and enables doctors to perform millions of corrective” laser eye surgeries. Canadian Prime Minister Justin Trudeu acknowledge the achievements of Mourou and Strickland: “Their innovative work can be found in applications including corrective eye surgery, and is expected to have a significant impact on cancer therapy and other physics research in the future.”
DONNA STRICKLAND
Donna
Theo Strickland born on 27 May 1959, is a Canadian Optical Physicist and
pioneer in the field of Pulsed Lasers. She is a Professor at the University of Waterloo.
She served as fellow, vice president, and president of The Optical Society, and is currently chair of their Presidential Advisory Committee. In 2018, she was listed as one of BBC’s 100 Women. She became the third woman ever to be awarded the Nobel Prize in Physics, after Marie Curie in 1903 and Maria Goeppert Mayer in 1963. Strickland and Mourou published their pioneering work "Compression of amplified chirped optical pulses" in 1985, while Strickland was still a doctoral student under Mour.
When she received the Nobel Prize, many commentators were surprised that she had not reached the rank of full professor. In response, Strickland said that she had "never applied" for a professorship; "it doesn't carry necessarily a pay raise… I never filled out the paperwork… I do what I want to do and that wasn't worth doing.
TOOLS MADE OF LIGHT
She served as fellow, vice president, and president of The Optical Society, and is currently chair of their Presidential Advisory Committee. In 2018, she was listed as one of BBC’s 100 Women. She became the third woman ever to be awarded the Nobel Prize in Physics, after Marie Curie in 1903 and Maria Goeppert Mayer in 1963. Strickland and Mourou published their pioneering work "Compression of amplified chirped optical pulses" in 1985, while Strickland was still a doctoral student under Mour.
When she received the Nobel Prize, many commentators were surprised that she had not reached the rank of full professor. In response, Strickland said that she had "never applied" for a professorship; "it doesn't carry necessarily a pay raise… I never filled out the paperwork… I do what I want to do and that wasn't worth doing.
TOOLS MADE OF LIGHT
The Inventions being honoured this year
have revolutionised laser physics. Extremely small objects and incredibly fast
process now appear in a new light. Not only Physics, but also Chemistry, Biology
and Medicine have gained precision instruments for use in basic research and
practical applications.
WHAT THEY DID?
The Nobel was divided between two major innovations in Laser Technology. Lasers are devices that create and amplify a single source of light. Light that comes out of a laser is one colour, or one wavelength, and does not spread out or weaken the way a flashlight beam would.
Immediately after the invention of lasers in 1960’s Ashkin started trying to, manipulate objects with light, he discovered that small translucent particles could be pushed using the force from a laser beam particles first were trapped in the centre of a beam, and then pinned in place using another laser aimed from the opposite direction. These optical tweezers could then be used to control and direct individual cells, viruses, proteins, and even atoms.
Strickland and Mourou worked together on laser amplification, producing the shortest and most intense bursts of laser energy ever created by humans. In research that would be used for Strickland‘s doctoral thesis, the pair manipulated beams of light to make them more powerful.
WHY IT MATTERS?
These innovations in light give researchers access to manipulate and study interactions that are too tiny and too fast for conventional methods.
Lasers are used daily in laboratories around the world. Ashkin’s optical tweezers enable scientists to cut, move, contain and inspect particles like strands of DNA and individual cell organelles.
Mourou and Strickland’s CPA method has been used to help millions of people with laser eye surgery and the cameras that use their technology can capture chemical interaction or even electrons in motion around an atom.
CONCLUSION
The inventions being honoured this year have revolutionized Laser Physics. Extremely small objects and incredibly rapid processes as now being seen in a new light. Advanced precision instruments are opening up unexpected areas of research and multitude of industrial and medical applications.
The work of Ashkin, Mourou and Strickland really does fulfill Alfred Nobel’s that the prizes recognize work that has been of the “greatest benefit to mankind”.
Reference
WHAT THEY DID?
The Nobel was divided between two major innovations in Laser Technology. Lasers are devices that create and amplify a single source of light. Light that comes out of a laser is one colour, or one wavelength, and does not spread out or weaken the way a flashlight beam would.
Immediately after the invention of lasers in 1960’s Ashkin started trying to, manipulate objects with light, he discovered that small translucent particles could be pushed using the force from a laser beam particles first were trapped in the centre of a beam, and then pinned in place using another laser aimed from the opposite direction. These optical tweezers could then be used to control and direct individual cells, viruses, proteins, and even atoms.
Strickland and Mourou worked together on laser amplification, producing the shortest and most intense bursts of laser energy ever created by humans. In research that would be used for Strickland‘s doctoral thesis, the pair manipulated beams of light to make them more powerful.
WHY IT MATTERS?
These innovations in light give researchers access to manipulate and study interactions that are too tiny and too fast for conventional methods.
Lasers are used daily in laboratories around the world. Ashkin’s optical tweezers enable scientists to cut, move, contain and inspect particles like strands of DNA and individual cell organelles.
Mourou and Strickland’s CPA method has been used to help millions of people with laser eye surgery and the cameras that use their technology can capture chemical interaction or even electrons in motion around an atom.
CONCLUSION
The inventions being honoured this year have revolutionized Laser Physics. Extremely small objects and incredibly rapid processes as now being seen in a new light. Advanced precision instruments are opening up unexpected areas of research and multitude of industrial and medical applications.
The work of Ashkin, Mourou and Strickland really does fulfill Alfred Nobel’s that the prizes recognize work that has been of the “greatest benefit to mankind”.
Reference
Journals
Internet
Submitted by
1. POOJA KALAL
2. PRIYANKA VIJAYAN
3. RESHMA P K
4. RESHMA RAJAN N
5. SANGEETHA M
6. SHILPA A
7. SHREEVALLI M
Submitted date :21-08-2019
Submitted date :21-08-2019
