A spectrometer sample head including a housing, at least one source of radiation in the housing, and a flip top sample cell. If the radio frequency applied to the electrode is f, the parasitic capacity C between the grounded portion of the housing and a conductive portion through which the radio frequency propagates is less than 1210*f0. Located on the lower wall and extending beyond each side wall is a flange member that forms an inherent lip. The method has applications in optical transmission networks as add-drop nodes and optical regenerators, for generation of high bandwidth optical signals, and for secret optical communications. The system and method may be used with modulation formats with a short pulse width and a broad optical spectrum.