Configurations for an optical device used for light splitting and wavelength locking are disclosed. The optical device may be a two by three coupler with a first waveguide coupled to a second waveguide, and a third waveguide coupled to the second waveguide. The first and third waveguides may receive input light and optically couple light to the second waveguide. The output signals of the first, second, and third waveguides may have a constant phase difference from one another over a broadband wavelength range, which may allow for phase unwrapping. By phase unwrapping the output signals over an FSR and performing further phase unwrapping over the broadband wavelength range, a continuous signal may be produced and used to sequentially lock each wavelength of light emitted by light sources over the broadband wavelength range.

Disclosed herein are integrated photonics systems (3800) for biosensing including an interrogator photonic circuit (3802) and cartridge (3804) and methods using these systems. The cartridge (3804) comprises a sensor photonic integrated subcircuit. The cartridge (3804) is configured to receive a biological sample. The interrogator photonic circuit (3802) is optically coupled to the cartridge (3804) an comprises: (i) a light source (3806) configured to generate light; and (ii) one or more waveguides configured to carry the light, wherein the light is used to determine a characteristic of the biological sample in the cartridge (3804). A system can have an assembly of a plurality of modular photonic integrated subcircuits. Each subcircuit can be pre-fabricated and can be configured to transfer light to and receive light from another subcircuit based on the first functionality. An output port of a first subset of the subcircuits can be configured to be aligned with an input port of a second subset of the subcircuits. At least one subcircuit can be configured to be removed from the first integrated photonics assembly and connected to a second integrated photonics assembly having a second functionality. The first integrated photonics assembly can be different from the second integrated photonics assembly and the first functionality can be different from the second functionality.

A system and method for securing communication over an optical fiber are disclosed. The system includes a transmit spatial multiplexer configured to couple a plurality of optical signals into respective ones of a plurality of spatial paths of an optical fiber, each of the spatial paths being able to carry an optical signal; wherein at least one of the plurality of optical signals is an optically modulated version of a desired sequence of information that is intended to be transferred over the optical fiber; and wherein at least one of the plurality of optical signals is an optical chaff signal; whereby a tap along the fiber cannot determine the transmitted desired sequence of information.

A device may be provided comprising at least one optoelectronic component and at least one optical waveguide, which are configured to transfer light between the optoelectronic component and the optical waveguide, wherein the optical waveguide contains at least one first longitudinal portion in which at least one Bragg grating is introduced, which has a grating constant which is variable along the longitudinal extent of said Bragg grating, and the optoelectronic component is arranged at a lateral distance from the optical waveguide. Alternatively or in addition, a method may be provided for transferring light between at least one optoelectronic component and at least one optical waveguide.

To provide an optical multiplexing circuit that can accurately monitor light of a plurality of wavelengths, and that can tolerate degradation of LDs. An optical multiplexing circuit includes m sets of multiplexers configured to multiplex light output from n connection waveguides being a plurality of connection waveguides wherein a multiplexing unit configured to input and multiplex light output from the m sets of the multiplexers from m input waveguides, an output waveguide configured to output light multiplexed by the multiplexing unit, and n×m or m branching units being inserted into n×m connection waveguides of the plurality of connection waveguides or the m input waveguides are provided on a same substrate.

An optical connection structure includes a first spatial multiplex transmission line, a second spatial multiplex transmission line, a first lens arrangement, a second lens arrangement and a first beam diameter conversion portion. The first spatial multiplex transmission line has a plurality of first transmission lines. The second spatial multiplex transmission line has a plurality of second transmission lines. The first lens arrangement is optically coupled with the first spatial multiplex transmission line. The second lens arrangement is optically coupled with the second spatial multiplex transmission line. The first beam diameter conversion portion has a first end face and a second end face and arranged between the first spatial multiplex transmission line and the first lens arrangement. The first beam diameter conversion portion is configured such that an optical diameter at the second end face is larger than an optical diameter at the first end face.

A wavelength monitoring apparatus includes a wavelength monitoring circuit. The wavelength monitoring circuit includes: a split circuit that splits an input optical signal into two; an optical delay circuit that applies a delay time difference to the two split optical signals; and a two-input two-output optical multiplexer/demultiplexer circuit that outputs a result of applying multiplexing interference to the optical signals to which the delay time difference has been applied. The wavelength monitoring apparatus further includes photoelectric conversion elements that perform photoelectric conversions on the two optical signals output from the wavelength monitoring circuit so as to output electrical signals. The wavelength monitoring apparatus is configured to obtain the wavelength of the optical signal, by calculating a ratio between two electrical outputs of the photoelectric conversion elements and referring to a correspondence table indicating wavelengths of optical signals input to the wavelength monitoring circuit and ratios between electrical outputs.

Embodiments of the disclosure provide a demultiplexer for processing a multiplexed optical input. The demultiplexer may include a plurality of Mach-Zehnder Interferometric (MZI) stages for converting the multiplexed optical input into a plurality of component optical signals. Each of the plurality of component optical signals corresponds to a respective wavelength-space component of the multiplexed optical input. A plurality of bandpass filters, each having a respective wavelength passband, may receive one of the plurality of component optical signals. The plurality of bandpass filters generates a plurality of demultiplexed optical signals based on the plurality of component optical signals.

We describe a space-division multiplexed (SDM) fibre, reconfigurable, wavelength-selective switch (WSS). The switch comprises a space-division multiplexed (SDM) optical input port to receive a space-division multiplexed (SDM) optical input signal comprising a plurality of space division modes each of said space division modes carrying a respective data signal, wherein each of said space division modes is also wavelength division multiplexed (WDM); an optical space division demultiplexer, coupled to said input port, to split said space-division multiplexed (SDM) optical input signal into a plurality of space division demultiplexed optical signals on separate demultiplexer outputs of said demultiplexer, each said demultiplexer output of said demultiplexer comprising a wavelength division multiplexed one of said plurality of space division modes; a set of reconfigurable wavelength-selective optical switches, each reconfigurable wavelength-selective optical switch having a switch input and a set of N switch outputs, and each including a dispersive element and a controllable beam steering element such that each said reconfigurable wavelength-selective optical switch is reconfigurable to selectively direct different respective wavelengths of a WDM optical signal at said switch input to different selected outputs of said set of N switch outputs, and wherein each said demultiplexer output is coupled to said switch input of a respective one of said set of reconfigurable wavelength-selective optical switches; and a set of optical space division multiplexers, one for each of said N switch outputs, each said optical space division multiplexer having a set of multiplexer inputs and a multiplexer output, to re-multiplex optical signals at said multiplexer inputs into a space-division multiplexed optical output signal at said multiplexer output, and wherein, for each of said set of optical space division multiplexers, each multiplexer input of said set of multiplexer inputs is coupled to said switch output of a different respective one of said set of reconfigurable wavelength-selective optical switches.

A device may be provided comprising at least one optoelectronic component and at least one optical waveguide, which are configured to transfer light between the optoelectronic component and the optical waveguide, wherein the optical waveguide contains at least one first longitudinal portion in which at least one Bragg grating is introduced, which has a grating constant which is variable along the longitudinal extent of said Bragg grating, and the optoelectronic component is arranged at a lateral distance from the optical waveguide. Alternatively or in addition, a method may be provided for transferring light between at least one optoelectronic component and at least one optical waveguide.