A photonic integrated circuit (PIC) in which some optical waveguides have laterally tilted waveguide cores used to implement passive polarization-handling circuit elements, e.g., suitable for processing polarization-division-multiplexed optical communication signals. Different sections of such waveguide cores may have continuously varying or fixed lateral tilt angles. Different polarization-handling circuit elements can be realized, e.g., using different combinations of end-connected untilted and laterally tilted waveguide-core sections. In some embodiments, laterally tilted waveguide cores may incorporate multiple-quantum-well structures and be used to implement active circuit elements. At least some embodiments beneficially lend themselves to highly reproducible fabrication processes, which can advantageously be used to achieve a relatively high yield of the corresponding PICs during manufacture.

In one aspect, a photonic device includes a substrate layer comprising magnesium fluoride and an optical guiding layer disposed on the substrate layer. The optical guide layer includes silicon dioxide. The substrate layer and the optical guide layer are transparent at an ultraviolet and visible wavelength range. In another aspect, a method includes oxidizing silicon to form a silicon dioxide layer, bonding the silicon dioxide layer to magnesium fluoride, removing the silicon and performing lithography and etching of the silicon dioxide to form a photonic device.

The invention relates to a photonic sensor chip comprising a semiconductor substrate with a cavity extending from a back side through an entire depth of the semiconductor substrate, a photonic plane located on the front side of the semiconductor substrate. The chip includes a photonic particle sensor element with an active-surface element having an exposed active surface facing towards the back side of the semiconductor substrate, for capturing selected particles from at least one fluid or gas to which the active surface is exposable. The cavity provides access to the active surface from the back side. The photonic particle sensor element receives an optical input wave via the photonic plane, to expose captured particles on the active-surface element to interaction with the optical input wave and to provide a resulting optical output wave having a spectral component indicative of the interaction between the optical input wave and captured particles.

The invention relates to a photonic sensor chip comprising a semiconductor substrate with a cavity extending from a back side through an entire depth of the semiconductor substrate, a photonic plane located on the front side of the semiconductor substrate. The chip includes a photonic particle sensor element with an active-surface element having an exposed active surface facing towards the back side of the semiconductor substrate, for capturing selected particles from at least one fluid or gas to which the active surface is exposable. The cavity provides access to the active surface from the back side. The photonic particle sensor element receives an optical input wave via the photonic plane, to expose captured particles on the active-surface element to interaction with the optical input wave and to provide a resulting optical output wave having a spectral component indicative of the interaction between the optical input wave and captured particles.

In one aspect, a photonic device includes a substrate layer comprising magnesium fluoride and an optical guiding layer disposed on the substrate layer. The optical guide layer includes silicon dioxide. The substrate layer and the optical guide layer are transparent at an ultraviolet and visible wavelength range. In another aspect, a method includes oxidizing silicon to form a silicon dioxide layer, bonding the silicon dioxide layer to magnesium fluoride, removing the silicon and performing lithography and etching of the silicon dioxide to form a photonic device.

A multi-chip module (MCM) includes: an interposer, a photonic chip, an optical gain chip, and a waveguide-fiber connector. The photonic chip, which may be electrically coupled to the interposer, may be implemented using a silicon-on-insulator (SOI) technology, and may include an optical waveguide that conveys an optical signal. Moreover, the optical gain chip, which may be electrically coupled to the interposer, may include a III-V compound semiconductor, and may include a second optical waveguide that conveys the optical signal and that is vertically aligned with the optical waveguide relative to a top surface of the interposer. Furthermore, the waveguide-fiber connector may be mechanically coupled to the interposer, and remateably mechanically coupled to an optical fiber coupler that includes the optical fiber. The waveguide-fiber connector may convey the optical signal between the optical waveguide in the photonic chip and the optical fiber.

Disclosed herein are composite materials and methods of making and use thereof. The composite materials can comprise: a porous periodic nanolattice layer having a first refractive index, and a continuous layer having a second refractive index and being disposed on the porous periodic nanolattice layer; the first refractive index and the second refractive index being different; wherein the porous periodic nanolattice layer comprises a plurality of pores defined by a nanolattice formed of hollow members, the plurality of pores being periodic. Also disclosed herein are methods of making a composite material, the methods comprising: forming a patterned layer; depositing a first material on the patterned layer, thereby forming a coated patterned layer; depositing a buffer material layer on the coated patterned layer, thereby forming a planarized layer; depositing a continuous layer on the planarized layer; and removing the buffer material layer and the patterned layer, thereby forming the composite material.