The present invention discloses a directional photonic coupler (1) with independent tuning of the coupling factor and phase difference. The coupler comprises: two waveguides (4, 5), with respective propagation constants “β.sub.1, β.sub.2”, on which phase shifters (6, 7) configured to modify the propagation coefficients are located. Both phase shifters are configured such that, by independent modification (differential or unique) of the propagation coefficients, the power coupling factor (K) between an input signal (2a or 2b) and the output signals (3b and 3a) is tuned, and by equal and simultaneous modification of the propagation coefficients, the common phase difference of the optical output signals (3 a, 3b) is tuned. A third phase shifter (15) can be used to retune the phase difference at the input/output of one of the waveguides. The coupler is of particular interest in PIC circuits, coupled resonators, Mach-Zehnder interferometers and mesh structures.

An object is to provide an optical communication system and an optical communication method that are capable of, when assigning wavelengths on a per-service basis and providing services on a per-area basis, preventing degradation of signal quality due to linear crosstalk and preventing an increase in cost and size. An optical communication system according to the present invention includes an optical splitter 300 connecting N first ports and M second ports by a combination of 2×2 fiber optical splitters, N and M each being an integer of two or more, where wavelengths of optical signals to be received are limited for each group of optical receivers 106, by using a correlation between a fused extension length of at least one 2×2 fiber optical splitter directly connected to the first port, among the 2×2 fiber optical splitters, and wavelength output characteristics of the second port of the optical splitter 300.

An optical waveguide includes a first waveguide core, a second waveguide core, a first subwavelength multilayer cladding, a second subwavelength multilayer cladding and a third subwavelength multilayer cladding. The first waveguide core and the second waveguide core have a width (w) and a height (h). The first waveguide core is disposed between the first subwavelength multilayer cladding and the second subwavelength multilayer cladding. The second waveguide core is disposed between the second subwavelength multilayer cladding and the third subwavelength multilayer cladding. Each subwavelength multilayer cladding has a number (TV) of alternating subwavelength ridges having a periodicy (A) and a filling fraction (p). A total coupling coefficient (|/c|) of the first waveguide core and the second waveguide core is from 10 to 0.

An optoelectronic chip includes optical inputs having different passbands, a photonic circuit to be tested, and an optical coupling device configured to couple said inputs to the photonic circuit to be tested.

One example system comprises a substrate and a waveguide disposed on the substrate to define an optical path on the substrate. The waveguide is configured to guide, inside the waveguide and along the optical path, a light signal toward an edge of the waveguide. The edge defines an optical interface between the waveguide and a fluidic optical medium adjacent to the edge of the waveguide. The system also includes an optical fluid and a fluid actuator configured to adjust a physical state of the optical fluid based on a control signal. The adjustment of the physical state of the optical fluid causes an adjustment of the fluidic optical medium adjacent to the edge.

A method includes defining a first waveguide in a first region of an optical device over a first dielectric layer over a silicon on insulator (SOI) substrate of the optical device and disposing a second dielectric layer on the first waveguide and the first dielectric layer of the optical device. The method also includes defining a second region on the second dielectric layer, the first dielectric layer, and the SOI substrate. The second region includes an integrated trench structure defined in the SOI substrate. The method further includes etching the second region to form an etched second region, disposing a third dielectric layer in the etched second region, and disposing a second waveguide on at least the third dielectric layer. The second waveguide is disposed to provide an optical coupling between the second waveguide and the first waveguide.

An optical waveguide includes a first waveguide core, a second waveguide core, a first subwavelength multilayer cladding, a second subwavelength multilayer cladding and a third subwavelength multilayer cladding. The first waveguide core and the second waveguide core have a width (w) and a height (h). The first waveguide core is disposed between the first subwavelength multilayer cladding and the second subwavelength multilayer cladding. The second waveguide core is disposed between the second subwavelength multilayer cladding and the third subwavelength multilayer cladding. Each subwavelength multilayer cladding has a number (TV) of alternating subwavelength ridges having a periodicy (A) and a filling fraction (p). A total coupling coefficient (|/c|) of the first waveguide core and the second waveguide core is from 10 to 0.

An optical grating coupler defining an axis and configured to couple light between a planar waveguide and an optical fiber, including first and second entry surfaces and a plurality of scattering regions symmetric to the axis and arranged such scattering strength presented to incoming light by the plurality of scattering regions changes from weak to strong along a beam path of the incoming light to match a Gaussian mode profile of the optical fiber.

An optoelectronic chip includes optical inputs having different passbands, a photonic circuit to be tested, and an optical coupling device configured to couple said inputs to the photonic circuit to be tested.

There is provided a device (300;500;700) for collecting fluorescent light (322) emitted by particles (304) in a medium (302). The device (300;500;700) comprises a substrate (308) having a chamber (306) for holding the medium (302) including the particles (304) being capable of emitting fluorescent light (322). A first waveguide (310), which is arranged to receive and guide excitation light along a first direction (313), extends through the chamber (306). Fluorescent light (322) emitted by the particles (304) following an excitation is collected by the first waveguide (310). The device (300;500;700) further comprises a coupler (316;516) which includes a second waveguide (317) arranged to output collected fluorescent light (326) at one of its ends (318). The second waveguide (317) is arranged in relation to the first waveguide (310) such that collected fluorescent light (324) travelling in a direction opposite to the first direction (312) is coupled out from the first waveguide (310) directly into the second waveguide (317).