Abstract: An optical sensor for monitoring the motion and/or position of a moving element. One preferred embodiment of the optical sensor (50) includes a soda lime silicate glass substrate (52) in which a plurality of transmit waveguide channels (54), (56), and (58) are formed by an ion diffusion process. The waveguide conveys light pulses to a plurality of read ports (60), (62), and (64) through which the pulses are emitted to illuminate reflective areas formed on the surface of an adjacent moving element (59). Pulses of light reflected back from the reflective areas re-enter the read ports, propagating in the opposite direction through combination transmit/receive portions of the optical waveguide channels (72), (74), and (76), combining in a common receive waveguide channel (78).

Abstract: An optical sensor system for multiplexing a plurality of channels conveying information encoded by light reflected from areas on a moving surface. An optical sensor head (10,10') is connected to a plurality of discrete wavelength light sources (122,126,130) by an optical fiber (14). Alternatively, a single source 70 of relatively wide spectral bandwidth may be coupled to the optical fiber. Light is conveyed by the optical fiber to the optical sensor head, passes through a waveguide channel to a plurality of branching junctions (18 and 42) long pass interference filters (20 and 44) are disposed. Light having a wavelength shorter than a predetermined value is reflected into a branching waveguide channel (24 and 48), while light having a longer wavelength is transmitted through the filter. Light that passes through both of the long pass interference filters enters a waveguide channel (60).