Aspects of the present disclosure describe systems, methods and structures for providing semiconductor amplifiers exhibiting a low polarization-dependent gain.

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.

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.

Polarization-insensitive optical amplifiers are an alternative to current Erbium Doped Fiber Amplifiers, which provide wideband coverage while remaining cost and space effective for use in submarine cable applications. Polarization-insensitive optical amplifiers are an improvement to current semiconductor optical amplifier systems by providing desirable polarization-dependent gain and wideband coverage. This is achieved using polarization rotators comprised of a SOI-based waveguide and a twisted optical circuit.

Embodiments of the present disclosure are directed to a silicon photonics integrated apparatus that includes an input to receive an optical signal, a splitter optically coupled to the input to split the optical signal at a first path and a second path, a polarization beam splitter and rotator (PBSR) optically coupled with the first path or the second path, and a semiconductor optical amplifier (SOA) optically coupled with the first path or the second path and disposed between the splitter and the PBSR. Other embodiments may be described and/or claimed.

A dummy light module includes a dual semiconductor optical amplifier (SOA) light source configured to emit two substantially identical light emissions. The two light emissions include a first light emission and a second light emission, both having a first polarization. The dummy light module further includes a polarization rotator configured to rotate the second light emission to a second polarization, and a polarization beam combiner configured to generate dummy light by combining the first light emission with the first polarization and the second light emission with the second polarization.

In one embodiment of the invention, a semiconductor optical amplifier (SOA) in a laser ring is chosen to provide low polarization-dependent gain (PDG) and a booster semiconductor optical amplifier, outside of the ring, is chosen to provide high polarization-dependent gain. The use of a semiconductor optical amplifier with low polarization-dependent gain nearly eliminates variations in the polarization state of the light at the output of the laser, but does not eliminate the intra-sweep variations in the polarization state at the output of the laser, which can degrade the performance of the SS-OCT system.

A tunable laser assembly housed in a single enclosure and a method of control is described wherein the tunable laser, pump and semiconductor optical amplifier do not share a common optical axis but are all aligned to optical waveguides on an intervening planar lightwave circuit (PLC). Wavelength monitoring circuitry is included on the PLC to enable monitoring and control of the tunable laser center wavelength and optical bandwidth. The design of the PLC does not introduce perturbations into the swept-source laser output spectrum that would cause artifacts in imaging applications such as optical coherence tomography (OCT).

A line field optical coherence tomography (OCT) system and an absorption spectrometer system employing a tunable or swept laser architecture. The laser is a cat's-eye configuration with a preferably transmissive tilt tuned interference thin film filter.