The present invention relates to a semiconductor optical amplifier, the semiconductor optical amplifier including: a plurality of optical amplification regions arranged in series; a passive waveguide region provided between optical amplification regions; and first and second electrodes provided on an upper surface of each of the optical amplification regions. The passive waveguide region electrically insulates between the first electrodes and between the second electrodes of the adjacent optical amplification regions and optically connects the adjacent optical amplification regions. The semiconductor optical amplifier electrically connects the first electrode and the second electrode of the respective adjacent optical amplification regions so that the plurality of optical amplification regions are electrically connected in cascade, and feeds power to the optical amplification regions at both ends of arrangements of the plurality of optical amplification regions thereby driving the plurality of optical amplification regions.

Higher power tunable lasers are feasible using photonics integrated circuit based external cavity laser configurations by using multiple RSOAs inside a single cavity to provide multiple on-chip coherent optical output at the same wavelength. The total collective output power in various output branches potentially adds up being higher than what commercial lasers can provide. Using multiple RSOA increases and distributes the number of gain materials, which keeps them in a linear regime and avoids available gain saturation, which thereby removes gain saturation limitation in optical amplifications.

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.

An integrated optical beam steering device includes a planar dielectric lens that collimates beams from different inputs in different directions within the lens plane. It also includes an output coupler, such as a grating or photonic crystal, that guides the collimated beams in different directions out of the lens plane. A switch matrix controls which input port is illuminated and hence the in-plane propagation direction of the collimated beam. And a tunable light source changes the wavelength to control the angle at which the collimated beam leaves the plane of the substrate. The device is very efficient, in part because the input port (and thus in-plane propagation direction) can be changed by actuating only log.sub.2 N of the N switches in the switch matrix. It can also be much simpler, smaller, and cheaper because it needs fewer control lines than a conventional optical phased array with the same resolution.

A variable wavelength light source and an apparatus including the same are disclosed. The variable wavelength light source includes: a first waveguide; a second waveguide spaced apart from the first waveguide; a first optical amplifier including a first gain medium; and a second optical amplifier including a second gain medium that is different from the first gain medium.

Beam steering devices and optical apparatuses including the beam steering devices are provided. A beam steering device includes a light source configured to generate input lights having first different wavelengths, a multiplexer configured to simultaneously receive the generated input lights, and multiplex the received input lights into a multiplexed light, and an optical splitter configured to split the multiplexed light. The beam steering device further includes an optical modulator configured to modulate the split light, and an emitter configured to simultaneously emit output lights having second different wavelengths to different points arranged in a first direction, based on the modulated light.

Embodiments relate to a high power supercontinuum (SC) fiber optical source. The SC fiber optical source includes a prebroadening optical fiber that broadens the spectrum of a lower power intermediate optical signal before final amplification. The spectrum broadening creates spectral components which facilitate further spectrum broadening of amplified signal in final nonlinear stage, allowing to achive flatter and wider spectrum, and reduces nonlinear Stimulated Brillouin Scattering (SBS) that could damage SC fiber optical source components or limit the output power of the SC fiber optical source signal, thus enabling higher output power. After amplification in booster, passing at least part of broadened spectrum, the optical signal spectrum is further broadened by injecting the optical signal into a nonlinear stage to create a SC optical signal.

Embodiments relate to a high power supercontinuum (SC) fiber optical source. The SC fiber optical source includes a prebroadening optical fiber that broadens the spectrum of a lower power intermediate optical signal before final amplification. The spectrum broadening creates spectral components which facilitate further spectrum broadening of amplified signal in final nonlinear stage, allowing to achieve flatter and wider spectrum, and reduces nonlinear Stimulated Brillouin Scattering (SBS) that could damage SC fiber optical source components or limit the output power of the SC fiber optical source signal, thus enabling higher output power. After amplification in booster, passing at least part of broadened spectrum, the optical signal spectrum is further broadened by injecting the optical signal into a nonlinear stage to create a SC optical signal.

Higher power tunable lasers are feasible using photonics integrated circuit based external cavity laser configurations by using multiple RSOAs inside a single cavity to provide multiple on-chip coherent optical output at the same wavelength. The total collective output power in various output branches potentially adds up being higher than what commercial lasers can provide. Using multiple RSOA increases and distributes the number of gain materials, which keeps them in a linear regime and avoids available gain saturation, which thereby removes gain saturation limitation in optical amplifications.

A method of providing electrical isolation between subsections in a waveguide structure for a photonic integrated device, the structure comprising a substrate, a buffer layer and a core layer, the buffer layer being located between the substrate and the core and comprising a dopant of a first type, the first type being either n-type or p- type, the method comprising the steps of prior to adding any layer to a side of the core layer opposite to the buffer layer: selecting at least one area to be an electrical isolation region, applying a dielectric mask to a surface of the core layer opposite to the buffer layer, with a window in the mask exposing an area of the surface corresponding to the selected electrical isolation region, implementing diffusion of a dopant of a second type, the second type being of opposite polarity to the first type, and allowing the dopant of the second type to penetrate to the substrate to form a blocking junction.