GE scientists specializing in laser technology development at GE Global Research, the technology development arm for the GE, on May 14 marked the 50th anniversary of the invention of the laser with the launch of “Laser Diode-logues” – a new blog feature on the Research Lab’s technology blog, Edison’s Desk, www.edisonsdesk.com. The anniversary is this Sunday, May 16.
“Through Laser Diode-logues, we will celebrate the achievements of the past 50 years in laser technologies and talk about future innovations that GE and others are working on that will define the next 50 years,” said Kevin Harding, Principal Scientist at GE Global Research and a fellow and past president of SPIE, the international society for optics and photonics.
The first blog post highlights GE’s first big breakthrough in lasers, the invention of the semiconductor (diode) laser in 1962. Invented by GE scientist Robert Hall, the diode laser’s impact still looms large today helping to enable everything from the world wide web, TV remote controls and price code scanning in stores. Watch a video interview of Robert Hall providing his recollections of this major invention.
Harding added, “Today, we don’t think twice when surfing the internet, scanning cable channels with our TV remote, listening to a CD or moving more swiftly through the check-out line at the grocery store. All of these common, everyday conveniences were made possible, in large part, by GE’s invention of the diode laser.“
Robert Hall’s career as a physicist in GE’s R&D labs spanned more than 40 years. An area where he had significant impact was in semiconductor technologies, which GE continues to drive today in applications such as silicon carbide power devices and thin film solar cells. By the time he retired in 1987, he had received 43 patents and many prestigious honors along the way. In 1994, he was elected to the National Inventors Hall of Fame.
How does a diode laser work?
The word LASER is an acronym for “Light Amplification by Stimulated Emission of Radiation.” Fundamentally, lasers work by using energy, either optically or electrically, to excite a material, or gain medium, which then amplifies light. This light is then directed into a cavity (think of it as light sandwiched between two mirrors), where the light bounces back and forth repeatedly causing even more light to be emitted. Different materials can be used to generate this reaction and operate a laser. A diode laser is simply a type of laser where the gain medium is a semiconductor—materials such as gallium arsenide, gallium nitride, or indium phosphide, to name a few. Most of the lasers in our daily lives, from CD players to price code scanners in stores to laser printers, are laser diodes.
Robert Hall’s invention of the diode laser was the first of several major contributions GE scientists have made in the field of laser technology. One area where GE’s contributions in lasers have been most significant is in advanced manufacturing applications.
Over the years, GE has pioneered the use of lasers in manufacturing ranging from laser hole drilling in aircraft blades to the first use of lasers for surface treatment of blades for better strength. Lasers are also used to weld filaments for lighting products, lamination spacers for generators and components for X-ray tubes. In recent years, GE has developed new applications of the laser that include the measurement of precision parts in production applications, the repair of power generation parts, and the processing of solar panel materials.