A beam deflection device includes multiple light-emission structures arranged adjacent to each other in a first direction (X direction). The light-emission structures are each configured to be capable of emitting, from its device surface, a line beam that extends in the first direction in the far field. Furthermore, the light-emission structures are each configured to allow the line beam to be scanned in a second direction (Y direction) that is orthogonal to the first direction.

A semiconductor laser source including a Mach-Zehnder interferometer including first and second arms. Each of these arms being divided into a plurality of consecutive sections. The first and second arms each include a gain-generating section forming first and second gain-generating waveguides, respectively. The laser source includes power sources able to deliver currents through the gain-generating waveguides such that the following condition is met:

[00001]$\underset{n=1}{\overset{N_2}{.Math.}}.Math.L_{2,n}.Math.{\mathrm{neff}}_{2,n}-\underset{n=1}{\overset{N_1}{.Math.}}.Math.L_{1,n}.Math.{\mathrm{neff}}_{1,n}=k_f.Math.{}_{\mathrm{Si}}$

where: k.sub.f is a preset integer number higher than or equal to 1, N.sub.1 and N.sub.2 are the numbers of sections in the first and second arms, respectively, L.sub.1,n and L.sub.2,n are the lengths of the nth sections of the first and second arms, respectively, neff.sub.1,n and neff.sub.2,n are the effective indices of the nth sections of the first and second arms, respectively.

Systems and methods of undersea optical communication are provided. An undersea optical amplifier assembly can include a water-tight housing and a photonic integrated circuit disposed within the housing. The photonic integrated circuit includes a plurality of optical fiber inputs, each configured to receive an end of a respective optical fiber of a first fiber optic cable bundle, and a plurality of optical fiber outputs. Each optical fiber output corresponds to a respective optical fiber input to form a fiber optic input-output pair, and is configured to receive an end of a respective optical fiber of a second fiber optic cable bundle. The photonic integrated circuit includes an optical amplifier optically coupled to each respective fiber optic input-output pair. The housing includes a first water-tight access port configured to receive the first fiber optic cable bundle, and a second water-tight access port configured to receive a second fiber optic cable bundle.

An optically pumped tunable VCSEL swept source module has a VCSEL and a pump, which produces light to pump the VSCEL, wherein the pump is geometrically isolated from the VCSEL. In different embodiments, the pump is geometrically isolated by defocusing light from the pump in front of the VCSEL, behind the VCSEL, and/or by coupling the light from the pump at an angle with respect to the VCSEL. In the last case, angle is usually less than 88 degrees. There are further strategies for attacking pump noise problems. Pump feedback can be reduced through (1) Faraday isolation and (2) geometric isolation. Single frequency pump lasers (Distributed feedback lasers (DFB), distributed Bragg reflector lasers (DBR), Fabry-Perot (FP) lasers, discrete mode lasers, volume Bragg grating (VBG) stabilized lasers can eliminate wavelength jitter and amplitude noise that accompanies mode hopping.

A method of providing a fiber Bragg grating (FBG) within a laser diode package is proposed that includes first inserting the fiber into the package (typically a stripped end termination of the optical fiber) and aligning the fiber with the laser diode. Once aligned, an external FBG writing system is used to illuminate a selected section of the fiber in place in the package (the package remaining open at this time) in a manner that creates the specific grating line pattern for a particular FBG. When using a UV-based system with a phase mask, a focusing lens is disposed between the phase and the open package to direct the interfering beams into the core region of the stripped fiber. A high-power femtosecond laser source may be used in an alternative arrangement to directly write the structure and form the in-package FBG.

An amplification device includes an element for splitting an input optical signal into first and second optical signals having first and second polarization modes, first and second amplification stages each including polarized SOAs for amplifying the first and second optical signals depending on driving currents, an intermediate processing stage for compensating optical characteristics of the optical gain bandwidth of the first amplification stage depending on driving currents, an element for combining the first and second optical signals outputted by the second amplification stage to produce an output optical signal, and a control means producing the driving currents depending on information representative of powers of the first and second optical signals before the polarized SOAs of each amplification stage and on a targeted power of the output optical signal.

A light source device includes a light source that generates incoherent light, and an optical amplifier having gain characteristics indicating a gain at each wavelength, which receives the incoherent light output by the light source as input light, and outputs amplified light obtained by amplifying the input light, and a central wavelength of an intensity distribution indicating an intensity at each wavelength of the input light is a wavelength longer than a central wavelength of the gain characteristics indicating a gain at each wavelength of the optical amplifier.

Conventional integrated optical amplifiers, which combine different types of platforms, e.g. silicon photonic integrated circuit for the device layer, and a Group III-V material for the gain medium, typically include a curved waveguide extending through the gain medium coupled to waveguides in the main device layer. Unfortunately, the radius of curvature of the curved waveguide becomes a limiting factor for both size and amplification. Accordingly, an optical amplifier which eliminates the need for the curved waveguide by including a coupler for splitting an input optical signal into two sub-beams, for passage through the gain medium, and a reflector, such as a U-turn, for reflecting or redirecting the two sub-beams back through the gain medium to the coupler for recombination, would be a welcome improvement. A phase tuner may also be provided to ensure coherence cancellation between the two sub-beams to maximize output and minimize back reflection without requiring an isolator.

An optical source includes semiconductor optical amplifiers, with a semiconductor other than silicon, which provide an optical gain medium. Moreover, a photonic chip in the optical source, which is optically coupled to the semiconductor optical amplifiers, includes ring resonators that selectively pass corresponding optical signals having carrier wavelengths provided by the semiconductor optical amplifiers, where a given ring resonator and a reflector on one of the semiconductor optical amplifier defines an optical cavity, and the ring resonators have different radii with associated resonance wavelengths corresponding to the carrier wavelengths. Furthermore, the photonic chip includes a shared ring resonator, optically coupled to the ring resonators, that selectively filters the optical signals, where the shared ring resonator has a different radius than the radii of the ring resonators with an associated resonance wavelength, and a free-spectral range of the shared ring resonator defines a spacing between the carrier wavelengths in the optical signal.

An embodiment of the present invention provides a photodetector chip, including a substrate, a semiconductor optical amplification section, and a photodetection section. The substrate includes a surface, the photodetection section and the semiconductor optical amplification section are arranged on the substrate, and the photodetection section is located in an optical signal output direction of the semiconductor optical amplification section. The semiconductor optical amplification section amplifies and filters an input optical signal to output an amplified and filtered optical signal to the photodetection section. The photodetection section is configured to convert the amplified and filtered optical signal into an electrical signal. The semiconductor optical amplification section includes a grating, the grating includes a first grating and a second grating that are cascaded, and the first grating is a slanted grating. The first grating and the second grating are configured to filter an optical signal entering the semiconductor optical amplification section.