US 6,542,671 B1Granted

Integrated 3-dimensional multi-layer thin-film optical couplers and attenuators

AssigneeSuper Light Wave Corp.

InventorsAbraham C. Ma, Tzu-Yih Chu

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Abstract

An integrated optical device has two waveguide layers that are patterned to provide 2-dimensional interconnected networks of waveguides. A filter layer between the two waveguide layers is made by sputter deposition of thin films with alternating indexes of refraction. Light traveling vertically through the filter layer experiences an interferometric effect. A deflecting bump is formed in the plane of the lower waveguide layer. The bump is isotropicly etched, undercutting a photo-mask over the bump, producing a rounded, concave profile to the bump. High-index material is deposited over the bump and patterned to form a waveguide that has light deflected by the bump upward. The filter is formed over the bump to receive the deflected light. The filter reflects some light back down to the bump to another waveguide in the first layer. Light transmitted vertically up through the filter is bent to the horizontal plane of the upper waveguide layer.

Claims20

Dependent claims

A three-dimensional integrated optical network comprising:

a substrate having a top surface;
a lower waveguide layer, formed above the substrate, containing optical waveguides in a lower plane substantially parallel to the top surface;
a deflecting bump, formed above the substrate and formed in the lower plane of the lower waveguide layer, the deflecting bump formed before the lower waveguide layer is formed, the lower waveguide layer bending upward over the deflecting bump;
a filter, formed over the deflecting bump, the filter receiving incident light from the lower waveguide layer that is deflected upward out of the lower plane by the deflecting bump, the filter reflecting a reflected portion of the incident light back down to the deflecting bump which bends the reflected portion back into a waveguide in the lower plane of the lower waveguide layer;
and
an upper waveguide layer containing optical waveguides in an upper plane that is above and substantially parallel to the lower plane and the top surface;
wherein the filter transmits a transmitted portion of the incident light, the transmitted portion of light being transmitted upward through the filter and bent into the upper plane by a waveguide from the upper waveguide layer that contacts the filter,
whereby the filter receives light deflected upward from the lower waveguide layer by the deflecting bump, the filter transmitting light upward to the upper waveguide layer and reflecting light back downward to the lower waveguide layer.

5 more elements

An integrated multi-layer optical device comprising:

input waveguide means, formed using a first waveguide layer of optical conducting material, for conducting an input beam of light in a horizontal direction;
deflect means, formed from an optical isolator material, for deflecting light in the input waveguide means to a vertical direction from the horizontal direction;
filter means, receiving light from the input waveguide means that is deflected to the vertical direction by the deflect means, for reflecting a reflected portion of received light and for vertically transmitting a transmitted portion of received light;
reflected-output waveguide means, formed using the first waveguide layer, for conducting the reflected portion of received light collected from the filter means;
and
transmitted-output waveguide means, formed using a second waveguide layer, for conducting the transmitted portion of received light vertically transmitted through the filter means,
whereby the input beam is vertically transmitted through the filter means to the second waveguide layer and reflected to the first waveguide layer.

4 more elements

A multi-layer optical coupler comprising:

a substrate for supporting the multi-layer optical coupler;
a bump formed on the substrate, with a curved edge for guiding light from a first horizontal plane to an upward direction;
an input waveguide formed by patterning a lower waveguide layer of high-refractive index material, the input waveguide guiding light in the first horizontal plane to the bump and guiding light up over the bump;
a reflected-output waveguide formed by patterning of the lower waveguide layer, the reflected-output waveguide collecting light reflected downward near the bump and guiding light in the first horizontal plane;
a first low-refractive-index layer, formed over lower waveguides formed by patterning the lower waveguide layer and formed over the substrate between the lower waveguides that include the input waveguide and the reflected-output waveguide;
wherein a top surface of the first low-refractive-index layer is planarized to have a substantially flat top surface, the first low-refractive-index layer having a first opening over the bump that exposes the input waveguide and the reflected-output waveguide over the bump;
a filter formed over the first opening and contacting the input waveguide and the reflected-output waveguide over the bump, the filter upwardly transmitting a transmitted portion of light and downwardly reflecting a reflected portion of light;
a second low-refractive-index layer, formed over the filter and over the first low-refractive-index layer, having a second opening over a portion of a top surface of the filter;
and
a transmitted-output waveguide formed by patterning an upper waveguide layer of high-refractive index material, the transmitted-output waveguide guiding light in a second horizontal plane that is parallel to and above the first horizontal plane;
wherein the transmitted-output waveguide includes a portion that descends below the second horizontal plane through the second opening to contact the top surface of the filter;
wherein the transmitted-output waveguide receives the transmitted portion of light transmitted upwardly through the filter, the transmitted-output waveguide bending the transmitted portion of light into the second horizontal plane;
whereby light is guided from the first horizontal plane of waveguides upwardly to the filter and transmitted through the filter to the second horizontal plane of waveguides and reflected downwardly to the first horizontal plane of waveguides.

10 more elements

Dependencies are inferred from the claim text.