Interferometer having multiple scan carriages

A Fourier transform infrared spectroscopy system, comprising:

• a light source configured to emit infrared radiation;
• and
• an interferometer configured to receive the infrared radiation and to provide recombined radiation comprising first and second portions of reflected radiation having varying relative phases, the interferometer comprising:
• a beam splitter assembly mounted to a stationary base and configured to split the infrared radiation emitted from the light source into first and second portions of radiation and to recombine the first and second portions of reflected radiation to provide the recombined radiation;
• a fixed mirror mounted to the stationary base and configured to reflect the first portion of radiation to provide the first portion of reflected radiation to the beam splitter;
• a movable mirror configured to reflect the second portion of radiation to provide the second portion of reflected radiation to the beam splitter, the movable mirror being movable with respect to the beam splitter in a scan direction to change the phase of the second portion of reflected radiation relative to the first portion of reflected radiation;
• an upper scan carriage mounted to the stationary base via a pair of inner bearing flexures and movable in a first arc motion with respect to the stationary base, the beam splitter assembly, the fixed mirror and the movable mirror being positioned within a space between planes containing the pair of inner bearing flexures while in respective unflexed positions;
• and
• a lower scan carriage mounted to the upper scan carriage via a pair of outer bearing flexures and movable in a second arc motion with respect to the upper scan carriage, the second arc motion being substantially equal to the first arc motion, while arcing in an opposite direction,
• wherein the movable mirror is attached to the lower scan carriage such that movement of the upper scan carriage in the first arc motion and movement of the lower scan carriage in the second arc motion enable movement of the movable mirror in the scan direction;
• and
• a detection system for receiving the recombined radiation.

An interferometer of a Fourier transform infrared spectroscopy system, the interferometer comprising:

• a fixed assembly comprising a base, a beam splitter configured to split light emitted from a light source into first and second portions of light, and a fixed mirror for reflecting the first portion of light,
• a movable assembly, movable with respect to the fixed assembly, comprising an upper scan carriage, a lower scan carriage and a movable mirror connected to the lower scan carriage for reflecting the second portion of light, wherein the beam splitter is further configured to combine the reflected first and second portions of light into a recombined radiation beam;
• a pair of inner bearing flexures having upper ends connected to the base and lower ends connected to the upper scan carriage, enabling movement of the upper scan carriage relative to the base;
• and
• a pair of outer bearing flexures having upper ends connected to the upper scan carriage and lower ends connected to the lower scan carriage, enabling movement of the lower scan carriage relative to the upper scan carriage,
• wherein an upper point in an upper plane of the upper scan carriage defines an upper arc during the movement of the upper scan carriage, and a lower point in a lower plane of the lower scan carriage defines a lower arc, equal and opposite to the upper arc, during the movement of the lower scan carriage, wherein the upper point and the lower point are geometric conjugates, enabling a scan movement of the movable mirror such that a plane containing the movable mirror is maintained parallel to a plurality of planes containing the movable mirror at a corresponding plurality of distances between the movable assembly and the fixed assembly during the scan movement.