A new development in optical reflectometry, the Agilent 8504B precision reflectometer, signifi- cantly extends measurement capa- bilities. The two-event resolution is better than 25 micrometers, while the dynamic range exceeds 80 dB. A measurement tool now exists specifically for the designer and manufacturer of precision lightwave components and connectors. The sensitivity exceeds that of the best power meter solutions, while the resolu- tion is sufficient to isolate each individual reflection within a small, complex optical assembly.