Abstract: 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.