System and method using a voltage kick-off to record a hologram on a photorefractive polymer for 3D holographic display and other applications

An apparatus for recording a hologram, comprising:

• a recording medium comprised of a photorefractive polymer between a ground electrode and a high-voltage electrode;
• a voltage source for applying a DC voltage between said high-voltage and ground electrodes to establish an electrical field across the polymer, said polymer having an optimal electrical field at which the diffraction efficiency is maximum and a higher electric field at which the diffraction efficiency has a local minimum;
• a coherent light source that supplies an object beam that interferes with a reference beam at the photorefractive polymer to record a hologram, said beams being removed prior to the recorded hologram reaching a steady-state diffraction efficiency;
• a controller that controls the voltage source to apply a high electric field above the optimal field across the photorefractive polymer when the object and reference beams are writing the hologram and to apply a low electric field once the object and reference beams are removed.

A method for recording computer generated holograms in a recording device for refreshable holographic 3D display, said recording device including a photorefractive polymer situated between a ground electrode and a segmented high voltage electrode with one or more hogels defined for each segment of the segmented electrode, said photorefractive polymer having an optimal electrical field at which the diffraction efficiency is maximum, comprising:

• a) providing computer generated images for multiple perspectives of a 3D object to be displayed for each said hogel;
• b) interfering a reference beam and an object beam at a position on the recording device;
• c) applying a voltage to a segment of the segmented high voltage electrode to establish a high electric field above the optimal field across the one or more hogels in the photorefractive polymer;
• d) translating the recording device so that the reference and object beams are positioned at a first hogel for said segment;
• e) modulating the object beam with the computer generated images for said first hogel to record a hologram;
• f) repeating steps d and e until the last hogel for the segment is recorded;
• g) after removing the object and reference beams from the last hogel reducing the voltage applied to the segment to switch the high electric field to a low electric field;
• and
• h) repeating steps c through g for the next segment of the segmented high voltage electrode until holograms are recorded for all of the hogels for each said segment.

An apparatus for recording computer generated holograms in a recording device for refreshable holographic 3D display, comprising:

• a recording device comprised of a photorefractive polymer between a ground electrode and a segmented high-voltage electrode with one or more hogels defined for each segment;
• a memory that stores computer generated images for multiple perspectives of a 3D object to be displayed for each said hogel;
• a voltage source for applying a DC voltages between said segmented high-voltage and ground electrodes to independently establish an electrical field across the photorefractive polymer in each electrode segment, said polymer having an optimal electrical field at which the diffraction efficiency is maximum;
• a coherent light source that supplies an object beam that interferes with a reference beam at a position on the photorefractive polymer;
• a spatial light modulator that modulates the object beam with the computer generated images for a specific hogel;
• a multi-axis translation stage that moves the recording device so that the modulated object and reference beams are positioned to record a hologram for said specific hogel;
• a first controller that controls the voltage source to apply a high electric field above the optimal field across the photorefractive polymer when object and reference beams are writing the hologram and to apply low electric field once the object and reference beams are removed from the last hogel in each said segment;
• and
• a second controller that controls the translation stage that translates the recording device from hogel to hogel with said beams being removed prior to said hogel reaching a steady-state diffraction efficiency until holograms are recorded for each hogel to record a 3D hologram of said 3D object for display.