Calibrated optical fiber power meters: Errors due to variations in connectors

We discuss potential errors in the measurement of optical fiber power when using a calibrated power meter with connectors of various types and from different vendors. Data are given on the error and standard deviation due to biconic connectors from a limited number of vendors. We speculate that the error is due to reflecting surfaces on the connector end. To confirm the hypothesis, we tested two connectors whose reflective ends have noticeable differences. The data illustrate the variability seen among connectors. Our data indicate that a user should expect measurement error in most cases. We issue a call for caution based on the results.