Arrays of fiber pigtails can be used to project and receive light. Unfortunately, most fiber pigtail arrays are not aligned well enough for coherently combining different optical beams. This imprecision stems in part from misalignment between the optical fiber and the endcap spliced to the end of the optical fiber. The endcap is often polished, curved, or patterned, causing the light emitted by the endcapped fiber to refract or diffract as it exits the endcap. This refraction or diffraction shifts the apparent position of the beam waist from its actual position. Measuring this virtual beam waist position before and after splicing the endcap to the fiber increases the absolute precision with which the fiber is aligned to the endcap. This increase in absolute precision reduces the deviation in virtual beam waist position among endcapped fibers, making it easier to produce arrays of endcapped fibers aligned precisely enough for coherent beam combining.

A cavity is etched in a stack of layers which includes a first layer made of a first material and a second layer made of a second material. To etch the cavity, a first etch mask having a first opening is formed over the stack of layer. The stack of layers is then etched through the first opening to a depth located in the second layer. A second mask having a second opening, the dimensions of which are smaller, in top view, than the first opening, is formed over the stack of layer. The second opening is located, in top view, opposite the area etched through the first opening. The second layer is then etched through the second opening to reach the first layer. The etch method used is configured to etch the second material selectively over the first material.

The present disclosure relates to a method for forming a cavity that traverses a stack of layers including a bottom layer, a first portion of which locally presents an excess thickness, the method comprising a first step of non-selective etching and a second step of selective etching vertically in line with the first portion.

A semiconductor package includes a semiconductor device, an encapsulating material, and a redistribution structure. The semiconductor device includes a chamfer disposed on one of a plurality of side surfaces of the semiconductor device. The encapsulating material encapsulates the semiconductor device. The redistribution structure is disposed over the encapsulating material and electrically connected to the semiconductor device.

Passive alignment and connection between a fiber array and a plurality of optical waveguides terminating along an edge of a photonic IC is provided by a controlled mating between V-grooves formed in a fiber support substrate and alignment ridges formed to surround waveguide terminations along an edge of a photonic IC. The V-grooves of the fiber support substrate are spaced to define the same pitch as the waveguides on the photonic IC, with the height and width of the alignment ridges formed to engage with the V-grooves upon mating of the fiber support substrate with the photonic IC. The individual fibers are positioned within associated V-grooves such that their endfaces are retracted from a proximal end portion of the support structure. It is this proximal end portion that mates with the alignment ridges on the photonic IC.

An optical connector for optical coupling a plurality of optical fibers to a photonic integrated circuit (PIC) comprises a plurality of fiber trenches; a plurality of tiled flat mirrors; and a plurality of optical focusing elements; wherein each of the plurality of fiber trenches adjoins a corresponding titled flat mirror of the plurality of titled flat mirrors; and wherein each of the plurality of titled flat mirrors is placed in proximity to a corresponding optical focusing element of the plurality of optical focusing elements.

A two-dimensional (2D) optical fiber array component takes the form of a (relatively inexpensive) fiber guide block that is mated with a precision output element. The guide block and output element are both formed to include a 2D array of through-holes that exhibit a predetermined pitch. The holes formed in the guide block are relatively larger than those in precision output element. A loading tool is used to hold a 1N array of fibers in a fixed position that exhibits the desired pitch. The loaded tool (holding the pre-aligned 1N array of fibers) is then inserted through the aligned combination of the guide block and output element, and the fiber array is bonded to the guide block. The tool is then removed, re-loaded, and the process continued until all of the 1N fiber arrays are in place. By virtue of using a precision tool to load the fibers, the guide block does not have to be formed to exhibit precise through-hole dimensions, allowing for a relatively inexpensive guide block to be used.

A cavity is etched in a stack of layers which includes a first layer made of a first material and a second layer made of a second material. To etch the cavity, a first etch mask having a first opening is formed over the stack of layer. The stack of layers is then etched through the first opening to a depth located in the second layer. A second mask having a second opening, the dimensions of which are smaller, in top view, than the first opening, is formed over the stack of layer. The second opening is located, in top view, opposite the area etched through the first opening. The second layer is then etched through the second opening to reach the first layer. The etch method used is configured to etch the second material selectively over the first material.

A v-groove assembly is used to edge couple a lensed fiber (e.g., an optical fiber made of silica) with a waveguide in a photonic chip. The v-groove assembly is made from fused silica. Fused silica is used to so that an adhesive (e.g., epoxy resin) used in bonding the lensed fiber to the v-groove assembly and/or bonding the v-groove assembly to the photonic chip can be cured, at least partially, by light.

Passive alignment and connection between a fiber array and a plurality of optical waveguides terminating along an edge of a photonic IC (PIC) is provided by a controlled mating between alignment V-grooves formed in a fiber array support substrate and extra-array alignment ridges formed beyond the extent of a waveguide array integrated within the PIC. The height and width of the alignment ridges are formed to engage with the alignment V-grooves upon mating of the fiber array substrate with the PIC, providing passive alignment while maintaining a physical gap spacing g between the components (ensuring the integrity of the passive alignment).