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.

The present disclosure relates to a method of forming a tapered optical fiber, where the optical fiber has a cladding encasing a core and has an initial outer diameter. The method involves applying opposing forces to spaced apart sections of the optical fiber. The spaced apart sections define a length portion representing a waist region. While applying the opposing forces, simultaneously applying heat to the waist region to gradually produce a taper of the optical fiber within the waist region. The taper has a first diameter at a midpoint of the waist region which is less than the initial outer diameter. An etch operation is then performed by chemically etching at least a subportion of the waist region of the optical fiber to reduce the subportion to a second diameter which is less than the first diameter.

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.

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.

The disclosed subject matter relates generally to photonic integrated circuit chips, semiconductor assemblies or packagings, and a method of forming the same. More particularly, the present disclosure relates to placement of optical fibers on a photonics chip, and a semiconductor assembly including the photonics chip.

The present disclosure relates to a method of forming a tapered optical fiber, where the optical fiber has a cladding encasing a core and has an initial outer diameter. The method involves applying opposing forces to spaced apart sections of the optical fiber. The spaced apart sections define a length portion representing a waist region. While applying the opposing forces, simultaneously applying heat to the waist region to gradually produce a taper of the optical fiber within the waist region. The taper has a first diameter at a midpoint of the waist region which is less than the initial outer diameter. An etch operation is then performed by chemically etching at least a subportion of the waist region of the optical fiber to reduce the subportion to a second diameter which is less than the first diameter.

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 method of forming a tapered tip of a polarization-maintaining (PM) fiber includes inserting a tip of the PM fiber into a first etchant solution characterized by a first etching rate for the core of the PM fiber and a second etching rate for the stress members of the PM fiber, the second etching rate being lower than the first etching rate, withdrawing the tip of the PM fiber from the first etchant solution at a withdrawal rate, immersing the tip of the PM fiber in a second etchant solution for a time duration. The second etchant solution is characterized by a third etching rate for the core and a fourth etching rate for the stress members, the fourth etching rate being greater than the third etching rate. The method further includes withdrawing the tip of the PM fiber from the second etchant solution.

Embodiments herein include an optical system that passively aligns a fiber array connector (FAC) to a waveguide in a photonic chip. A substrate of the FAC is machined or etched to include multiple grooves along a common axis or plane to hold optical waveguides, or more specifically, the fibers of the optical cables in the FAC. To align the fibers to the photonic chip, one of the fibers is disposed in an alignment trench which has a width that is substantially the same as the diameter of the fiber. When the fiber registers with the alignment trench, the fiber is aligned with a waveguide disposed at the end of the trench. Because the pitch between the fibers can be precisely controlled, aligning one of the fibers using the alignment trench results in the other fibers becoming passively aligned to respective waveguides in the photonic chip.

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 1×N array of fibers in a fixed position that exhibits the desired pitch. The loaded tool (holding the pre-aligned 1×N 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 1×N 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.