Patent ID: 6265708
Filing Date: 2001-07-24
Classification: G02F

Abstract:
A method of controlling light comprising carrying out modulation of at least one of photosignal intensity and luminous flux density of a signal light by illuminating a photoelement comprised of a photoresponsive composition with a control light having a wavelength to which said photoresponsive composition responds, and thereby reversibly modulating at least one of transmittance and refractive index of said photoelement through which said signal light is being transmitted,wherein said method comprises converging said signal light and said control light respectively and illuminating them on said photoelement, and aligning optical paths of said control light and said signal light respectively so that said control light and said signal light are propagated on essentially the same optical path in said photoelement, and so that regions having the highest photon density in a vicinity of focal points of said control light and said signal light respectively overlap in said photoresponsive composition within said photoelement, andwherein said method further comprises differentiating and extracting a bundle of rays of said signal light in a region of said photoelement where said signal light has undergone profound modulation of at least one of said photosignal intensity and luminous flux density by extracting a bundle of rays that has been transmitted through said photoresponsive composition in said photoelement and exited therefrom with a smaller angular aperture than an emitting angle of said bundle of rays of said signal light.