The 828 Series High-Speed Optical Wavelength Meter uses interferometer technology that is very different than that employed by other wavelength meters used for WDM wavelength testing applications. A Fizeau etalon design is used to generate a spatial interferogram that is detected by a fast InGaAs 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.
The 828 High-Speed Optical Wavelength Meter measures the absolute wavelength of CW and modulated optical signals to an accuracy as high as ± 0.3 pm. This performance is maintained over long periods of time because the 828 system is automatically calibrated with a built-in laser diode whose wavelength is locked to a well-known absorption of acetylene. To verify the accuracy of the model 828, every system is rigorously tested with laser sources that are traceable to NIST standards.
Operation of the 828 High-Speed Optical Wavelength Meter is straightforward. The optical signal enters the model 828 through an FC (UPC or APC) fiber-optic connector on the front panel. The system’s high sensitivity results in an input power requirement as low as -40 dBm (0.1 µW). Automatic attenuation instantly adjusts the signal for optimum performance. A convenient touch-screen display, located on the front panel, controls the 828 system and displays the measured wavelength and power. The measurement information can also be sent to a PC using a variety of interface options that satisfy virtually any test application. An RS-422 serial interface is available for data streaming that can be triggered internally by the instrument itself or with a user-supplied trigger signal. Interfacing can also be done via a library of SCPI commands using a standard USB or Ethernet interface, or an optional GPIB interface. Finally, the 828 system is packaged in a rugged chassis (bench top or rack-mounted) for use in both laboratory and manufacturing environments.