Spatial-heterodyne interferometry for reflection and transmission (SHIRT) measurements

A method, comprising:

• digitally recording a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis using a first reference beam and a first object beam;
• digitally recording a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis using a second reference beam and a second object beam;
• Fourier analyzing the digitally recorded first spatially-heterodyned hologram, by shifting a first original origin of the digitally recorded first spatially-heterodyned hologram to sit on top of a first spatial-heterodyne carrier frequency defined by a first angle between the first reference beam and the first object beam, to define a first analyzed image;
• Fourier analyzing the digitally recorded second spatially-heterodyned hologram, by shifting a second original origin of the digitally recorded second spatially-heterodyned hologram to sit on top of a second spatial-heterodyne carrier frequency defined by a second angle between the second reference beam and the second object beam, to define a second analyzed image;
• digitally filtering the first analyzed image to cut off signals around the first original origin to define a first result;
• and
• digitally filtering the second analyzed image to cut off signals around the second original origin to define a second result;
• performing a first inverse Fourier transform on the first result, and
• performing a second inverse Fourier transform on the second result,
• wherein the first object beam is transmitted through an object that is at least partially translucent and the second object beam is reflected from the object.