Provided here are: a mounting section having a light-emitting element for emitting an optical signal; a mounting section arranged alongside the mounting section and having a light-emitting element for emitting an optical signal that is different in wavelength from the optical signal; and an optical multiplexer having a filter for transmitting therethrough only the wavelength of the optical signal, a mirror for reflecting the optical signal transmitted through the filter, and a filter arranged alongside the filter, for transmitting therethrough only the wavelength of the optical signal, and for reflecting the optical signal reflected by the mirror and multiplexing it with the transmitted optical signal; wherein the light-emitting element is mounted in the mounting section to be displaced toward the light-emitting element from a center in a width direction across an emission direction of the optical signal.

An optical device is provided. The optical device includes a fiber array and an optical assembly. The fiber array includes a common channel and a plurality of divided. channels arranged in parallel in a first direction and extending along a second direction, and the fiber array has a first surface from a top view perspective. The optical assembly is coupled to the first surface of the fiber array. The first surface and the common channel of the fiber array form an angle less than 90 degrees from the top view perspective.

Optical wavelength division multiplexing (WDM) devices include an optical chip having a number of waveguides therein, with a common optical fiber and single wavelength channel optical fibers optically coupled to the waveguides. Wavelength sensitive filters are disposed between the chip and the fibers, or across waveguides within the chip to reflect light at certain wavelengths and to transmit light at other wavelengths. In sonic embodiments, all of the fibers are located at the same end of the chip, in others the common fiber is located at one side of the chip and the single channel fibers located at another side, while in others the common fiber is located at a first side of the chip and the single channel fibers are located either at the first side of the chip or at a second side of the chip.

Provided is an optical communication device, such as a wavelength locker, a wavelength demultiplexer, an optical coupling system, and an optical switching system, using a small-sized lens element. An optical communication device includes, as a lens element, a liquid crystal diffractive lens element having an optically anisotropic layer that is formed using a composition containing a liquid crystal compound, and has a liquid crystal alignment pattern in which an orientation of an optical axis of the liquid crystal compound changes while continuously rotating toward one direction, in a radial shape from an inside toward an outside, and in the liquid crystal alignment pattern, in a case where a length over which the orientation of the optical axis rotates by 180° in one direction in which the optical axis changes is a single period, a length of the single period gradually decreases from the inside toward the outside.

A short-waveband active optical component based on a vertical emitting laser and a multi-mode optical fiber has an emitting end and a receiving end. In the emitting end, multiple VCSELs generate multiple optical signals of different wavelengths, and multiple photodiodes in the receiving end receive the optical signals emitted by the VCSELs. Both ends use a focusing lens array to collimate and focus the optical signals A Z-block-shaped prism performs a light combining function at the emitting end, while another Z-block-shaped prism performs a light splitting function at the receiving end. Both ends use a focusing lens for collimating and focusing the optical signals at ends of a multi-mode optical fiber, which is used for transmitting the optical signals generated by the VCSELs. The short-waveband active optical component has a small size and a high transmission rate.

Systems, devices, and techniques for performing wavelength division multiplexing or demultiplexing using one or more metamaterials in an optical communications systems are described. An optical device may be configured to shift one or more phase profiles of an optical signal using one or more stages of metamaterials to multiplex or demultiplex wavelengths of optical signals. The optical device may be an example of a stacked design with two or more stages of metamaterials stacked on top of one another. The optical device may be an example of a folded design that reflects optical signals between different stages of metamaterials.

An optical system, comprising: (i) multiple input optical fibers; (ii) an optical mode multiplexer/demultiplexer coupled to said input optical fibers with, said optical mode multiplexer/demultiplexer comprising a plurality of metamaterial structures having length and forming at least one stage of metamaterials, the at least one stage of metamaterials is being situated on a surface of the optical mode multiplexer/demultiplexer facing the input optical fibers, and the at least one stage of metamaterials is oriented at angles between 60 and 120 degrees relative to the axis of the input fibers; and the metasurfaces are structured to receive a first optical signal having a first mode from at least one of said multiple input optical fibers and convert the first mode to a different mode.

Disclosed herein are wavelength-division multiplexing devices using different angles of incidence (AOIs) at the WDM filters to provide for variable placement and orientation of WDM filters and channel ports, thereby decreasing the device footprint and allowing for shorter overall optical signal paths to increase signal performance and reliability. Also disclosed are stacked WDM filters for increased signal isolation.

The present disclosure discloses an optical module including: a circuit board; a housing assembly divided by a separation board into a first portion and a second portion that are stacked one above the other, wherein a light-emitting cavity is formed in the second portion, and a partition wall is provided in the first portion to separate the first portion into a light-receiving cavity and a slot, and is provided with a plurality of light-passing holes via which the light-receiving cavity is in communication with the slot; an optical fiber adapter disposed in the housing assembly and in communication with the light-receiving cavity; a light-emitting assembly arranged in the light emitting cavity and electrically connected to the circuit board, wherein heat generated by the light-emitting assembly is conducted to a surface of the housing assembly via the partition wall; and a light-receiving assembly.

Exemplary multi-channel optical couplers include a molded coupling module comprising a first surface, a second surface, a lens array receptacle, and fiber receptacles for optical fibers; an optical arrangement comprising: a particular surface carrying a reflective coating, and a further surface carrying a plurality of optical filters, each configured to pass a single optical wavelength; a first lens array configured such that each lens is optically aligned with the plurality of optical filters via at least the reflective coating, and with a position, within a particular fiber receptacle, corresponding to the end of a particular optical fiber; a second lens array arranged with the second surface such that each lens is optically aligned with an optical filter. The optical block and lens arrays can be configured such that the optical coupler produces no more than −10 dB of crosstalk on any of the optical wavelengths passed by the optical filters.