An optical device consists of one or more optical waveguides and mechanical light switches 30. When a
light switch 30 is turned on, it extracts
light beam 62a from a
waveguide core 20 and redirect the
light beam 62b into
free space, it redirects an incoming
light beam 80 from
free space and injects the light beam 80a into the
waveguide core 20, or it performs both functions at the same time, depending on specific applications. On and off states of a
light switch 30 are achieved by pulling the
light switch 30 into a close vicinity of the
waveguide core 20 and by pushing the light switch 30 away from the waveguide core 20, respectively. An interactive fiat-panel display can be built based on this invention. A plurality of
parallel channel waveguides forms a display panel. An array of light beams 62a, injected from an array
light source 60, propagates along waveguide cores 20 until reaches a location where a light switch 30 is turned on. At this location, the light switch 30 redirects the light beams towards a viewer. An image is produced when the light switches 30 are turned on sequentially while the light-intensity distribution on the array
light source 60 is synchronically updated. The panel display is capable of responding to an input optical
signal by detecting an incoming light beam 80 from a
light pen 100. An array of photodetectors 81 is used to identify the location of the incoming light beam 80 on the display panel and a computer is used to execute a corresponding action accordingly.