Dispersed fourier transform spectrometer

A dispersing Fourier Transform interferometer, comprising:

• optics for receiving and collimating a source light along a first optical path;
• a beamsplitter positioned for splitting the collimated source light into a second light beam along a second optical path substantially orthogonal to said first optical path;
• a first reflector positioned along said first optical path for reflecting light transmitted through said beamsplitter back toward said beam splitter;
• a second reflector positioned along said second optical path for reflecting said second light beam back toward said beamsplitter;
• a programmable drive-train coupled to at least one of said first and second reflectors for moving said coupled reflector along its associated optical path so as to introduce a variable path difference x between said first and second optical paths whereby said source light and said second light beam recombine at said beamsplitter and are recorded on a multielement detector at a variety of delays, comprising an interferogram;
• a metrology detector for determining the path length difference between the two reflectors;
• a dispersive element positioned along said second optical path for receiving a Fourier Transform Spectrometer output and for providing a resulting multiple narrowband interferogram outputs of different wavelengths representative of the source light input;
• a sensor including a plurality of light intensity sensing elements each separately responsive to said different wavelengths for producing a set of data of interferogram intensities Id measured at a set of discrete lags xi;
• and
• a processor for receiving and processing the data to produce a spectral output having a best fit with the set of data.

A method of determining a spectrum of a light source, comprising:

• receiving and collimating a source light along a first optical path;
• transmitting a first part of the collimated source light further along said first optical path while reflecting a second part of the collimated source light along a second optical path;
• reflecting back said first part of said collimated source light along said first optical path;
• reflecting back said second part of said collimated source light along said second optical path;
• introducing a path length difference x between said first and second optical paths;
• recombining said back-reflected first and second parts of said collimated source light;
• dispersing said recombined light into a plurality of different wavelengths;
• separately sensing an intensity I of each of said plurality of different wavelengths to thereby produce a set of data of interferogram intensities Id measured at a set of discrete lags xi;
• and
• processing the data so as to produce a spectral output having a best fit with the set of data.