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.

Methods, systems, and apparatus, for optical communication. One apparatus includes a Fabry-Perot (FP) laser diode assembly coupled to a first port of a circulator; an optical amplifier coupled to a second port of the circulator; a wavelength division multiplexer (WDM) filter coupled to a third port of the circulator; and a Faraday rotator mirror coupled to the WDM filter.

A link extender configured to extend a range of an optical transceiver module is provided. The link extender includes an array of semiconductor optical amplifiers (SOAs) configured to amplify an optical signal received from the optical transceiver module, a first plurality of variable optical attenuators (VOAs) configured to control a power output of the amplified optical signal output from the array of SOAs, and a plurality of dispersion compensation and filtering (DC&F) devices configured to compensate for chromatic dispersion of the optical signal.

A tunable or swept laser architecture that is appropriate for swept source optical coherence tomography and other applications including spectroscopy employing a cat's-eye configuration with a preferably transmissive tilt tuned interference thin film filter.

A room-temperature semiconductor maser, including a first matching network, a second matching network, a heterojunction-containing transistor, and a resonant network. The output end of the first matching network is connected to the drain of the heterojunction-containing transistor. The input end of the second matching network is connected to the source of the heterojunction-containing transistor. The gate of the heterojunction-containing transistor is connected to the resonant network. The pumped microwaves are fed into the input end of the first matching network.

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.

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 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 room-temperature semiconductor maser, including a first matching network, a second matching network, a heterojunction-containing transistor, and a resonant network. The output end of the first matching network is connected to the drain of the heterojunction-containing transistor. The input end of the second matching network is connected to the source of the heterojunction-containing transistor. The gate of the heterojunction-containing transistor is connected to the resonant network. The pumped microwaves are fed into the input end of the first matching network.

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.