Anritsu Co.'s optical sampling oscilloscope has a self-synchronization feature that enables operation without a separate divided clock input signal. It has a repetition frequency range of 4 to 500 GHz and can test high-speed optical communications devices and systems under development. Other features include pattern synchronization and burst application capabilities, and a module design that allows users to select sampling heads for specific analysis requirements. Modules, such as an independent polarization plug-in, can be installed via the front panel. The company says there are no limitations on trigger input ranges.