The 871 Laser Wavelength Meter measures the absolute wavelength of pulsed and CW lasers with the reliable accuracy required for the most demanding applications. What’s more, an unsurpassed measurement rate of 1 kHz enables the wavelength characterization of individual laser pulses, and the resulting time resolution of 1 ms provides the most detailed wavelength analysis of tunable lasers. The 871 Laser Wavelength Meter measures absolute wavelength to an accuracy as high as ± 175 MHz. This performance is maintained over long periods of time because the system is automatically calibrated with a built-in wavelength standard. A unique Fizeau etalon design is used to generate a spatial interferogram that is detected by a fast photodetector array. Using an on-board digital signal processor, the interferometric data is processed quickly into an accurate wavelength measurement. The combination of these technologies provides an unmatched, sustained measurement rate of 1 kHz. Automatic pulse detection triggers data collection for asynchronous operation so the wavelength of every pulse is measured for lasers operating at repetition rates up to 1 kHz. At higher repetition rates, the system integrates all pulses arriving within a 1 ms measurement window, or an external trigger can capture individual pulses. The 871 Laser Wavelength Meter is available in two broad wavelength configurations to satisfy most experimental requirements. These ranges are the 350 - 1100 nm and 650 - 1700 nm. A pre-aligned fiber-optic input ensures optimum alignment resulting in uncompromised accuracy. The system operates with a PC running under Windows via standard USB or Ethernet interface. Software is provided to control measurement parameters and to report data, or the system can become part of an experiment using a library of commands for custom or LabVIEW programming. Measurement data can also be displayed using a web-based application with a tablet or smart phone.