Integrated optical switch array

Abstract

An optical switch array is provided in which at least three input waveguides are coupled to at least three output waveguides. Each of the input waveguides is coupled in the same order to each of the output waveguides by a coupling element such as a y-junction combiner, via an intermediate waveguide and a switching mechanism that includes a coupling element such as a 1 x 2 switch. For compactness, the coupling elements that couple to the same input waveguide are mutually displaced along the output waveguides.

Description

technical field [0001] The present invention relates to optical switch arrays, and more particularly to optical switch arrays of extremely small geometries in which random combinations of inputs and outputs are unambiguously addressable. Background technique [0002] Integrated optical switches are well-known technologies. For a review of the early state of the art, see Lars Thylen's "Integrated Optics in LiNbO3: recent developments in devices for telecommunications" Journal of Lightwave technology vol.6 no.6 (June 1988), pp 847-861 . The waveguide is fabricated on the substrate by locally processing the lithium niobate substrate to increase the refractive index. For example, the refractive index of lithium niobate can be locally increased by diffusing titanium into the substrate. To transfer light from one waveguide into another, they can be coupled by local optoelectronic control of their refractive index. Well-known examples of optoelectronic switches include direction...

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Problems solved by technology

[0009] 2. In general, the optical path from a specific input waveguide to a specific output waveguide through the crossbar array is not unique

This is less efficient than a switch package such as a double crossbar rectangular matrix as shown in Figure 3.

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