Download the N7784B datasheet PDF.
This datasheet also covers the N7784B_Agilent(Hewlett variant, as both devices belong to the same high speed polarization controller family and are provided as variant models within a single manufacturer datasheet.
Note: The manufacturer provides a single datasheet file (N7784B_Agilent(Hewlett-Packard).pdf) that lists specifications for multiple related part numbers.