Distributed resonant cavity light beam modulator

An optical apparatus comprising means for producing a coherent polarized beam of electromagnetic radiation having a preselected wavelength,

• a transparent layer means for receiving normally incident thereto the polarized beam and for supporting at least one resonant mode,
• grating means imposed on said layer means for establishing exclusively optical interaction with the layer means and having a grating period less than said preselected wavelength, to establish first order coupling with the normally incident beam,
• the layer means and grating means interacting responsive to receiving the normally incident polarized beam to couple the layer means with the grating means with the grating means exclusively providing the coupling of the beam into the layer means to produce a standing wave resonance by Bragg reflection in the layer means by second order coupling by the grating means, and
• control means coacting with the layer means and the grating means for controlling the relative indices of refraction of the layer means and the grating means for obtaining a resonance wavelength in the layer means equal to the preselected radiation wavelength and thereby high reflectance to modulate the polarized beam.

A spatial light modulator comprising an array of modulators onto which is directed a plurality of coherent polarized beams of electromagnetic radiation having a preselected wavelength, drive means connected to drive each modulator and photosensor means to sense light and responsive thereto to control said drive, each said modulator of said array comprising

• a transparent layer means for receiving at least one normally incident coherent polarized beam and for supporting at least one resonant mode and
• grating means associated with and imposed on said layer means of each said modulator for establishing exclusively optical interaction with the layer means and having a grating period less than said preselected wavelength, to establish first order coupling with the normally incident beam
• the layer means and associated grating means interacting to produce a standing wave resonance by Bragg reflection in the layer means by second order coupling by the grating means, and
• said drive means associated with each modulator controlling same to obtain in said layer means of each said modulator a resonance wavelength in the layer means equal to the preselected radiation wavelength and thereby high reflectance to modulate the at least one coherent polarized beam received thereby.