Fourier-transform hyperspectral imaging system

A Fourier-transform hyperspectral imaging system comprising:

• an optical imaging system configured to produce an image of an object and having an optical axis and input for an input radiation coming from points of the object;
• an adjustable birefringent common-path interferometer module comprising a movable birefringent element and configured to produce interfering replicas of said input radiation which are delayed from each other by a phase delay adjustable by the moving birefringent element;
• the interferometer module being configured to produce collinear replicas for entering optical rays parallel to said optical axis;
• a two-dimensional light detector reconfigured to receive the replicas and provide digital images of the object depending on said adjustable phase delay;
• an analysis device configured to perform a Fourier Transform of the digital images to obtain a hyperspectral representation of the object,
• wherein:
• a) said hyperspectral imaging system is configured so as to show in operation:
• a first peripheral ray of said input radiation having a first delayed phase φ1 associated with the adjustable birefringent common-path interferometer module;
• a second peripheral ray of said input radiation having a second delayed phase φ2 associated with the adjustable birefringent common-path interferometer module;
• an absolute difference Δφ of the first delayed phase φ1 and the second delayed phase φ2 smaller than a maximum value Δφmax comprised between 1.0 π rad and 1.8 π rad;
• b) the adjustable birefringent common-path interferometer module comprises:
• an adjustable wedge pair, including an optical wedge and a movable optical wedge, configured to provide the phase delay between radiation components having reciprocally orthogonal polarizations;
• the phase delay is dependent on a variable position of the movable optical wedge;
• an actuator module causing movement of the movable optical wedge.