The 438 Series Multi-Wavelength Meter combines proven Michelson interferometer-based technology with fast Fourier transform analysis in order to measure the wavelength, power, and OSNR of as many as 1000 discrete optical signals. With features such as high accuracy, a measurement rate of up to 10 Hz, and a broad operational range from 1000 to 1680 nm, the model 438 provides the most precise, efficient, and versatile WDM wavelength testing to satisfy the needs of any manufacturing engineer.
Two versions of the 438 Multi-Wavelength Meter are available. The model 438A is the most accurate, measuring wavelength to ± 0.3 pm. For less exacting test requirements, the model 438B is a lower-priced alternative with a wavelength accuracy of ± 1.0 pm. The wavelength accuracy of the 438 system is maintained over long periods of time because it is continuously calibrated with a built-in HeNe laser wavelength standard. In order to achieve the highest accuracy, the model 438A uses a single-frequency HeNe laser that is stabilized using a precise balanced longitudinal mode technique. A standard HeNe laser is used as the wavelength reference in the model 438B. The result is a confidence level of ≥ 99.7%. To verify this performance, every 438 system is rigorously tested with laser sources that are traceable to NIST standards.
Operation of the 438 Multi-Wavelength Meter is straightforward. The optical signal enters the model 438 through an FC (UPC or APC) fiber-optic connector on the front panel. The system’s high sensitivity results in an input power requirement of only -40 dBm (0.1 µW). Automatic electronic gain control instantly adjusts the photodetector signal for optimum performance. A convenient touch-screen display, located on the front panel, controls the 438 system and displays the measured wavelength, power, and OSNR in a variety of formats. Data from a specific optical channel can be displayed, or lists of data from all channels, sorted by wavelength or power, can be reported. The measurement information can also be sent to a PC using a library of SCPI commands via standard USB or Ethernet interface, or an optional GPIB interface. The 438 system is packaged in a rugged chassis (bench top or rack-mounted) for use in both laboratory and manufacturing environments.