Semiconductor lasers, allowing for indispensable science and a wide range of technologies, have become one of the most important enablers of photonics-based technologies. Vertical-cavity surface-emitting lasers (VCSEL), a vital class of semiconductor lasers, specifically, are gaining importance given their form factor and optoelectronic performance for their use as an optical source in high-speed, short-wavelength communications and sensors.
Researchers introduce and demonstrate a new design of a VCSEL combining MTCCs, which aims to enhance slow-light optical feedback, thus extending the temporal laser bandwidth (speed) beyond the limit of the relaxation oscillation frequency.
In their design, they propose and show that a VCSEL cavity surrounded by MTCCs adiabatically provides direct slow-light feedback from each TCC to the main lasing cavity. Therefore, even if the direct feedback from each cavity is only moderate, it will yet redistribute the optical field density by funneling the slow-light mode into the central cavity, which effectively allows generating sufficient feedback to extend the temporal laser bandwidth (speed).