Version 2.01 of the Microsoft Excel-based “Laser Reliability Workbook” has been released by ILX Lightwave Corp. The downloadable tool is used to analyze and plot laser diode and LED lifetime data. Up to 100 lifetime data points may be entered into the workbook, which automatically creates Weibull and lognormal probability plots of lifetime data and calculates the probability distribution parameters and times to failure. Built-in Arrenhius model calculations may be used to estimate time to failure at a second temperature. The new version calculates and displays confidence bounds for the life data. Instructions and example data are provided.