Science has lost a giant in the field of optical research. Arthur Ashkin died earlier this week at age 98, leaving behind a 40-year legacy of innovation at Bell Labs.
Arthur is best known for his invention of optical tweezers, a method for isolating and grabbing individual particles using optical lasers, for which he was awarded the Nobel Prize in Physics in 2018. This breakthrough actually was a byproduct of his communications research at Bell Labs into non-linear optical systems. This serves as the perfect example of the Bell Labs way: research into a specific communications problem leads to inventions of incalculable impact to science and society. Just as the search for a replacement to the vacuum tube led to the creation of the transistor and research into satellite radio transmission resulted in the discovery of the cosmic background radiation left over from the Big Bang, Arthur’s work in advanced laser optics produced advances that had an impact far beyond the world of communications.
Beginning his career at what was then AT&T Bell Laboratories in 1952, Arthur at first focused on microwave research but soon switched over the emerging field of lasers. In the 1960s, he and his Bell Labs colleagues discovered the photorefractive effect in piezoelectric crystals, which began the field of non-linear optics. He later pioneered the optical trapping and manipulation of small dielectric particles using optical gradient forces, which led to him being considered the father of laser radiation “pressure.”
It was in the 1980s that Arthur began to apply his optical trapping work to the invention of optical tweezers, and 1987, he demonstrated that they could be used to capture living bacteria without harming them. Optical tweezers are now widely used to investigate the machinery of life, and Arthur’s innovation provided – and continues to provide – the foundation for many advances in both the biological and physical sciences. For instance, that research led directly to fellow Bell Labs Nobel Laureate Steven Chu’s later pioneering work in using lasers to trap individual atoms in supercooled gases.
Arthur left an indelible imprint on Bell Labs and its optical research groups. Today Bell Labs remains the premier research institution for optical innovation. We continue to constantly push the limits of what is possible in optical communications, and we owe a large part of that drive and dedication to Arthur Ashkin.
Arthur retired from Bell Labs in 1992, but he didn’t disappear from the life of the Labs. He was a frequent attendee of coffee hours and company picnics. He will be greatly missed by us all.