Publications

In-situ OTDR for low-cost optical networks using a single-mode 850-nm VCSEL

Keeler, Gordon A.; Serkland, Darwin K.; Geib, K.M.; Peake, Gregory M.

A new approach to optical time-domain reflectometry (OTDR) is proposed that will enable distributed fault monitoring in singlemode VCSEL-based networks. In situ OTDR uses the transmitter VCSEL already resident in data transceivers as both emitter and resonant-cavity photodiode for fault location measurements. Also valuable at longer wavelengths, the concept is demonstrated here using an 850 nm oxide-confined VCSEL and simple electronics. The dead times and sensitivity obtained are adequate to detect the majority of faults anticipated in local- and metropolitan-area networks.