Abstract: A semiconductor optical amplifier (SOA) has an overall gain that is substantially polarization independent, i.e., less than 1 dB difference between transverse electric (TE) and transverse magnetic (TM) gain. The SOA includes a residual cladding layer having different thicknesses over different portions of the gain section. Over a first portion of the gain section, the residual cladding layer is thinner than over a second portion of the gain section. This results in the first portion providing more gain to optical energy having a TE polarization state than optical energy having a TM polarization state. In the second portion of the gain section, however, more gain is provided to optical energy having a TM polarization state than energy having a TE polarization state. The resulting gain differences can be designed to offset one another so that the output has a gain that is substantially polarization independent.

Abstract: A semiconductor optical amplifier (SOA) has an overall gain that is substantially polarization independent, i.e., less than 1 dB difference between transverse electric (TE) and transverse magnetic (TM) gain. The SOA includes gain and polarization rotation functions integrated onto a single substrate. According to one exemplary embodiment, a passive polarization rotation section is disposed between two active gain sections.

Abstract: An optical amplification device includes a depolarizer for reducing the polarization sensitivity requirements on an SOA by changing the input to the SOA from having an arbitrary (unknown) polarization state to a known (depolarized) state. The depolarizer receives an input optical signal and outputs a depolarized, optical signal, and a semiconductor optical amplifier (SOA) receives the depolarized optical signal and outputs an amplified optical signal.

Abstract: An optical device is provided comprising a gain section adapted to emit radiation at a radiation wavelength, a coupling section adjacent to the gain section for transitioning radiation between an active waveguide and a passive waveguide, and a passive section adjacent to the coupling section supporting a single-lobed optical mode in the passive waveguide at the radiation wavelength. The passive waveguide has an index of refraction and dimension such that the confinement of the radiation within the active waveguide in the gain section is reduced.

Abstract: An optical device is provided comprising a gain section adapted to emit radiation at a radiation wavelength, a coupling section adjacent to the gain section for transitioning radiation between an active waveguide and a passive waveguide, and a passive section adjacent to the coupling section supporting a single-lobed optical mode in the passive waveguide at the radiation wavelength. The passive waveguide has an index of refraction and dimension such that the confinement of the radiation within the active waveguide in the gain section is reduced.