An optical device may include a separating element to separate an optical signal into a plurality of spectral bands that are spatially or angularly separated along a band separation direction. Spectral ranges may differ among each spectral band of the plurality of spectral bands. The optical device may include a dispersive element comprising a plurality of dispersive regions. A dispersive region of the plurality of dispersive regions may disperse spectral components of a spectral band, of the plurality of spectral bands, along a dispersion direction to form a dispersed spectral band. The optical device may include a plurality of optical elements. An optical element of the plurality of optical elements may manipulate the dispersed spectral band in association with imaging the spectral band onto a detector area of a detector array. The optical device may include the detector array comprising the detector area.

Methods, systems and devices are described that improve optical spectroscopic techniques and particularly those that involve externally dispersed interferometer (EDI) techniques that result in an output spectrum having improved stability characteristics. The output spectrum minimizes the unwanted shifts in wavelength when the spectrograph component of the EDI instrument is under stresses that would otherwise shift or distort the wavelength positions of the spectrum.

An optical device, a system and a method for dispersion interferometry includes a frequency doubling device and an optical modulation device, a transmission beam path which is configured to emit a first and second measurement beam on an optical element and a reception beam path which is configured to receive a first and second measuring beam returned by the optical element.