Nanoelectromechanical interferometer for visible to infrared wavelengths

The present disclosure relates to an on-chip interferometer and a spectrometer comprising said interferometer. The present disclosure relates to an on-chip interferometer comprising a waveguide for propagation of an optical signal comprising an input waveguide; at least two interferometer arms comprising one or more slot waveguides; and an output waveguide; wherein the input waveguide is split into the at least two interferometer arms which are recombined into the output waveguide; and a control mechanism configured for controlling a relative time delay between optical signals propagating in the two interferometer arms by modifying one or more slot widths of one or more of the slot waveguides; and wherein the relative time delay is at least 1, 2, 5, or at least 10 fs or at least one optical period of the longest optical wavelength of the optical signal.