Ultrafast Semiconductor Ring Lasers for Optical Transport in 5G Networks

Abstract: The continuing increase of transmission rates and capacity at all levels of telecommunication and wireless networks raises demand for very high-speed, low-cost optical transmitters. In this talk, I will present our concept for low-cost, small-size injection-locked directly modulated laser sources with very high modulation bandwidths exceeding 100 GHz that could revolutionize the future of optical transport in 5G networks and optical telecommunication in general. Optical injection locking has been actively researched for its potential to improve ultrahigh frequency performance of semiconductor lasers for both digital and analog applications. We have proposed a new injection-locking scheme, based on unidirectional whistle-geometry ring lasers (WRLs) monolithically integrated with distributed Bragg reflector laser masters. Numerical analysis of the modulation response of a single injection-locked WRL shows a very significant reduction in the modulation efficiency between low frequency and the resonance frequency (low-frequency roll-off), which severely limits the achievable 3-dB modulation bandwidth. By combining advantages of strong injection locking (to dramatically enhance the resonance frequency) and cascaded arrangement of WRLs (to eliminate the low-frequency roll-off in modulation response), a new class of high-performance ultrafast, easy-to-use functional chips is expected to emerge.

Marek Osiński is a Professor of Electrical and Computer Engineering, Physics and Astronomy, and Computer Science at the University of New Mexico.  Read online bio.