AXT is a materials science company that develops and manufactures high-performance compound and single-element semiconductor substrate wafers, including indium phosphide, gallium arsenide, and germanium. These substrates are used when conventional silicon cannot meet the performance requirements of optoelectronic or semiconductor devices. End markets include data-center connectivity, silicon photonics, 5G infrastructure, passive optical networks, lasers, sensors, wireless power amplifiers, LEDs, and satellite solar cells. AXT is headquartered in Fremont, California, with manufacturing and raw-material investments in China, making demand cycles, export permits, and supply-chain geography important factors.