According to embodiments of the invention, the design and fabrication of a binary superimposed grating (BSG) results in better performing devices that may be fabricated using existing technology. The fabrication process includes forming grating features based upon repeating features of the desired superposition function. The design process also relaxes the processing requirement for equivalently performing devices.

A method, includes providing a wafer including a first surface grating extending over a first area of a surface of the wafer and a second surface grating extending over a second area of the surface of the wafer; de-functionalizing a portion of the surface grating in at least one of the first surface grating area and the second surface grating area; and singulating an eyepiece from the wafer, the eyepiece including a portion of the first surface grating area and a portion of the second surface grating area. The first surface grating in the eyepiece corresponds to an input coupling grating for a head-mounted display and the second surface grating corresponds to a pupil expander grating for the head-mounted display.

An optical fiber includes a core configured to transmit laser light and a cladding that surrounds the core. In some implementations, an outer surface region of the cladding is tapered or comprises a plurality of notches. The outer surface region of the cladding is configured to cause an aiming beam that falls incident upon the outer surface region of the cladding at a first incidence angle to fall incident upon an outer surface region of the core at a second incidence angle to allow the aiming beam to couple into the core.

A method, includes providing a wafer including a first surface grating extending over a first area of a surface of the wafer and a second surface grating extending over a second area of the surface of the wafer; de-functionalizing a portion of the surface grating in at least one of the first surface grating area and the second surface grating area; and singulating an eyepiece from the wafer, the eyepiece including a portion of the first surface grating area and a portion of the second surface grating area. The first surface grating in the eyepiece corresponds to an input coupling grating for a head-mounted display and the second surface grating corresponds to a pupil expander grating for the head-mounted display.

Improvements to gratings for use in waveguides and methods of producing them are described herein. Deep surface relief gratings (SRGs) may offer many advantages over conventional SRGs and Bragg gratings, an important one being a higher S-diffraction efficiency. In one embodiment, deep SRGs can be implemented as polymer surface relief gratings or evacuated Bragg gratings (EBGs). EBGs can be formed by first recording a holographic polymer dispersed liquid crystal (HPDLC) grating. Removing the liquid crystal from the cured grating provides a polymer surface relief grating. Polymer surface relief gratings have many applications including for use in waveguide-based displays.

Systems and embodiments for an integrated photonics mode splitter and converter are provided herein. In certain embodiments, a system includes a substrate having a first index of refraction. Additionally, the system includes a waveguide layer on the substrate, wherein the waveguide has a second index of refraction different from the first index of refraction. Also, the waveguide layer includes one or more mode splitters that receive at least one of a first photon in a first mode and a second photon in a second mode through an input port and provide one of the first photon through a first output port and the second photon through a second output port. The waveguide layer also includes a mode converter coupled to the second output of a mode splitter, wherein the mode converter receives the second photon through a port and outputs the second photon in the first mode through the port.

An optical fiber filter includes a fiber core, inner cladding, and outer cladding. A refractive index of the fiber core, a refractive index of the inner cladding, and a refractive index of the outer cladding progressively decrease in sequence. The fiber core is configured to transmit at least two mutually different first optical signal modes, the inner cladding is configured to transmit at least two mutually different second optical signal modes, and at least one fiber grating is etched on the fiber core. At least part of optical power of a target first optical signal mode is coupled to only a target second optical signal mode at the fiber grating. The target first optical signal mode is one of the at least two first optical signal modes, and the target second optical signal mode is one of the at least two second optical signal modes.

An MCF having a structure excellent in mass productivity and suppressing increases in splicing cost and loss are provided. The MCF includes 12 or 16 cores, a cladding, and a coating. The cores are arranged at positions of line symmetry while no adjacent relationship is established between the cores having an adjacent relationship with any core. A coating diameter is 235-265 μm, a cladding diameter CD is from CD.sub.nominal−1 μm to CD.sub.nominal+1 μm with a nominal value CD.sub.nominal of 195 μm or less, an MFD at 1310 nm is from MFD-reference-value −0.4 μm to the MCF-reference-value+0.4 μm with the MFD-reference-value of 8.2-9.2 μm, and a 22 m-cable-cutoff wavelength λ.sub.cc is 1260-1360 nm. A core's zero-dispersion wavelength is a wavelength-reference-value −12 nm to the wavelength-reference-value+12 nm with the wavelength-reference-value of 1312-1340 nm, and a dispersion slope at the wavelength is 0.092 ps/(nm.sup.2.Math.km) or less. A shortest distance from a cover-cladding interface to each core center, a structure, and optical characteristics satisfy predetermined conditions.

An MCF having a structure excellent in mass productivity and suppressing increases in splicing cost and loss are provided. The MCF includes 12 or 16 cores, a cladding, and a coating. The cores are arranged at positions of line symmetry while no adjacent relationship is established between the cores having an adjacent relationship with any core. A coating diameter is 235-265 μm, a cladding diameter CD is from CD.sub.nominal−1 μm to CD.sub.nominal+1 μm with a nominal value CD.sub.nominal of 195 μm or less, an MFD at 1310 nm is from MFD-reference-value−0.4 μm to the MCF-reference-value+0.4 μm with the MFD-reference-value of 8.2-9.2 μm, and a 22 m-cable-cutoff wavelength λ.sub.cc is 1260-1360 nm. A core's zero-dispersion wavelength is a wavelength-reference-value−12 nm to the wavelength-reference-value+12 nm with the wavelength-reference-value of 1312-1340 nm, and a dispersion slope at the wavelength is 0.092 ps/(nm.sup.2.Math.km) or less. A shortest distance from a cover-cladding interface to each core center, a structure, and optical characteristics satisfy predetermined conditions.

An optical fiber includes a core configured to transmit laser light and a cladding that surrounds the core. In some implementations, an outer surface region of the cladding is tapered or comprises a plurality of notches. The outer surface region of the cladding is configured to cause an aiming beam that falls incident upon the outer surface region of the cladding at a first incidence angle to fall incident upon an outer surface region of the core at a second incidence angle to allow the aiming beam to couple into the core.