A low-cost, system-on-chip for Optical Time Domain Reflectometry (OTDR)

A single-chip Optical Time Domain Reflectometer (OTDR) system-on-chip (SoC) for fiber-optic fault detection and localization is presented. The IC can be configured into several modes including high-performance mode (external modulator and expensive off-chip laser / APD), and low-cost mode (low power/gain and inexpensive laser / APD). Experimental optical measurements demonstrate that the maximum detectable fiber length of the proposed OTDR SoC can be as long as 25km, while the spatial resolution can achieve 2.5m, 4m and 10m, for various configurations. Compared with current discrete solutions on the market, the proposed OTDR system can reduce the cost by 100x, area by 5x, and power consumption by 4x.