Abstract
Single-mode (SM) vertical-cavity surface-emitting lasers (VCSELs), especially those operating around 850 nm, have been studied intensively in recent years for short distance transmission. Despite the demonstrations of increased data rate and system distance, the impact of frequency chirp that is commonly present in directly modulated lasers is an area that needs more detailed studies for 850 nm VCSEL-based systems. In this paper, we explore the interaction between a laser chirp and fiber chromatic dispersion using an 850-nm SM VCSEL over a standard SM fiber that is two-mode at the operating wavelength. Our transmission experiments show that the system can enjoy a benefit from negative fiber dispersion instead of a penalty compared to the back-to-back case, due to the favorable chirp–dispersion interaction, which is also supported by our system bandwidth measurements. Furthermore, we measure the chirp value of the SM VCSEL and conduct modeling using the time-domain pulse concept to illustrate the impact on the chirp–dispersion interaction and explore the optimal chirp parameters for different transmission data rates. Our study indicates a significant system benefit of using 850-nm SM VCSELs with a high bandwidth single-mode fiber around 850 nm due to the favorable chirp–dispersion interaction. Such a benefit can enable high data rate and longer distance system transmission for modern data center applications.
Highlights
For short distance communications, 850 nm multimode (MM) vertical-cavity surface-emitting laser (VCSEL)-based transmission systems over multimode fibers (MMFs) have been a low-cost solution for many years
We report the observation of a chirp of an 850-nm SM VCSEL and present a detailed study on the interaction between the laser chirp and fiber chromatic dispersion (CD) using the SM VCSEL over a gradedindex standard single-mode fiber
To the best of our knowledge, this is the first report of favorable interaction between the chirp of SM VCSEL and the negative dispersion of fiber at 850 nm, which could provide a new design parameter for optimizing VCSEL-based short reach transmission systems for data center applications
Summary
850 nm multimode (MM) vertical-cavity surface-emitting laser (VCSEL)-based transmission systems over multimode fibers (MMFs) have been a low-cost solution for many years. Around 850 nm, the wavelength for most of VCSEL transmission, the optical fibers (both MMF and standard single-mode fiber) have high negative dispersion that limits system performance beyond 25 Gb/s. We report the observation of a chirp of an 850-nm SM VCSEL and present a detailed study on the interaction between the laser chirp and fiber CD using the SM VCSEL over a gradedindex standard single-mode fiber. To the best of our knowledge, this is the first report of favorable interaction between the chirp of SM VCSEL and the negative dispersion of fiber at 850 nm, which could provide a new design parameter for optimizing VCSEL-based short reach transmission systems for data center applications.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
