Rapid switching optical shutter alternately transmitting visible radiation and near infrared radiation

An optical shutter that is rapidly switchable between optical states to alternately transmit visible radiation and near infrared radiation, comprising:

• a liquid crystal polarization modulator positioned to receive incident radiation for internal propagation through the liquid crystal polarization modulator, the internally propagating radiation having a polarization state, and the liquid crystal polarization modulator comprising a guest-host liquid crystal mixture that includes a liquid crystal director contained between first and second electrodes and that exhibits variable absorption of different radiation wavelength regions, depending on the orientation of the liquid crystal director relative to the polarization state of the internally propagating radiation;
• a first wavelength selective polarizing filter imparting a polarization state to incident radiation within the visible wavelength region but not imparting a polarization state to incident radiation within the near infrared wavelength region of the electromagnetic spectrum;
• a second wavelength selective polarizing filter imparting a polarization state to incident radiation within the visible wavelength region but not imparting a polarization state to incident radiation within the near infrared wavelength region of the electromagnetic spectrum, the first and second wavelength selective polarizing filters positioned adjacent different ones of the first and second electrodes of the liquid crystal polarization modulator;
• and
• the liquid crystal polarization modulator responsive to a first value and a second value of an applied control signal to switch the internally propagating radiation to, respectively, a first polarization state and a second polarization state to selectively produce, in cooperation with the first and second wavelength selective polarizing filters, optical shutter output radiation in the visible wavelength region and the near infrared wavelength region, the switching of the internally propagating radiation in the first polarization state causing transmission and blockage of the optical shutter output radiation within, respectively, the visible wavelength region and the near infrared region, and the switching of the internally propagating radiation to the second polarization state causing transmission and blockage of the optical shutter output radiation within, respectively, the near infrared wavelength region and the visible wavelength region.