Semiconductor Laser to Revolutionize Manufacturing

Most high-power designs are edge emitters composed of a sandwich of various semiconductor layers and emit light from a small, slit-shaped side region.

FREMONT, CA: For many years, semiconductor lasers, light-emitting chips the size of a grain of sand, have been the backbone of the optical communications sector, transmitting data signals around the globe via a network of optical fibers. However, they are inadequate for many other applications, especially those needing powerful laser light, such as marking or cutting metals. The primary issue with semiconductor lasers is their low beam quality, which results from their characteristic geometry. So, the output light has limited brilliance and is a striped beam that rapidly diverges as it travels.

This odd beam form is difficult to collect and control, making it challenging to create the nearly perfectly circular, sharply focused spot necessary for numerous applications. Thermal issues make it difficult to scale semiconductor lasers to high output outputs of hundreds of watts or kilowatts. As a result, other laser technologies, such as CO2 gas, crystal, and fiber, have become the technology of choice for many materials processing jobs in the industrial industry. However, these alternatives are huge, complex, and rather expensive; hence, a small, mass-producible semiconductor replacement is extremely desirable.

All of these appealing qualities are a direct result of the laser's design. A semiconductor layer patterned with a custom-designed periodic array of uniquely-shaped tiny air holes (nanometre scale). Machine learning and quantum computing are currently utilized to analyze and optimize the design and performance of their PCSELs. This structure establishes a unique resonance condition that produces a narrowband, highly directed emission.

The beam exits the PCSEL from the top rather than the side, and the design is scalable to produce large-area lasers with light-emitting patches in the range of millimeters or perhaps centimeters. The outputs of the most recent PCSELs from Kyoto are now in the tens of watts range for continuous wave (CW) operation and considerably higher for pulsed operation. The air holes' shape, size, and period are vital to the laser's operation.

With superior beam quality and capacity for high-power operation, PCSELs possess an additional attractive trait, the flexibility to include additional functionality directly into their design. The most recent intelligent PCSEL systems are based on a matrix of neighboring emitters that are individually controlled, which offers beam-steering and beam-shaping capabilities. It makes them a promising alternative for constructing a highly small LiDAR (laser range finding) sensor system for automobiles, driverless vehicles, and other sensing jobs.