Optical scanning holography system

An in-line scanning holography system comprising:

• a first polarizer configured to convert an inputted beam into a linearly polarized beam;
• a linear polarization direction converter comprising a variable wave plate and a quarter wave plate and being configured to change a polarization direction of the linearly polarized beam by retarding a phase of the linearly polarized beam incident from the first polarizer;
• a signal generator configured to apply a phase modulation signal for varying a phase retardation value with time to the linear polarization direction converter;
• wherein, according to the phase modulation signal of the signal generator,
• the variable wave plate is configured to change a first polarization of the linearly polarized beam incident from the first polarizer, and
• the quarter wave plate is configured to change a second polarization from the first polarization of the linearly polarization beam passing through the variable wave plate;
• a polarization-sensitive lens configured to receive the linearly polarized beam with the changed polarization direction output from the linear polarization direction converter and generate a first spherical wave of right-handed circular polarized light having a negative focal length and a second spherical wave of left-handed circular polarized light having a positive focal length;
• a second polarizer configured to pass only a beam component therethrough in a predetermined polarization direction among components of the generated first and second spherical waves;
• a scanning unit configured to scan an object by using an interference beam generated between the first and second spherical waves passing through the second polarizer;
• and
• a photodetector configured to detect a beam reflected from the object.