Three scientists, from the United States, France, and Canada, have been awarded the Nobel Prize in physics for advances in the field of laser physics. On Tuesday, the Swedish Royal Academy of Sciences awarded half the 9-million-kronor ($1.01 million) prize to Arthur Ashkin of the United States. The other half will be shared by Gerard Mourou of France and Canada’s Donna Strickland. Ashkin’s work was based on the realization that the pressure of a beam of light could push microscopic objects and trap them in position. A breakthrough came in 1987 when he used the new optical tweezers to grab living bacteria without harming them. Ashkin is the oldest-ever Nobel Prize winner at 96 years old. Strickland and Mourou helped develop short, intense laser pulses that have broad industrial and medical applications. They succeeded in creating ultrashort, high-intensity laser pulses without destroying the amplifying material. Strickland and Mourou’s technique, called chirped pulse amplification (CPA), has become standard for high-intensity lasers. Its uses include corrective laser eye surgeries. Strickland is the first woman to be named a Nobel laureate since 2015. She is also only the third to have won the physics prize — the first was Marie Curie in 1903. The inventions by the three scientists date back to the mid-1980s, and over the years they have revolutionized laser physics.