Optical Device
Provided is an optical device having a long lifetime and high reliability. An optical device according to one embodiment comprises at least one Mach-Zehnder (MZ) modulator and a redundant semiconductor optical amplifier (SOA). The redundant SOA is connected to at least one MZ modulator via a 2-input 2-output coupler. The redundant SOA includes two SOAs arranged in parallel, and the two SOAs are arranged in two waveguides connected to the 2-input 2-output coupler, respectively. The redundant SOA is configured to switch the two SOAs to amplify light modulated by the at least one MZ modulator or light obtained before modulation.
1 . An optical device, comprising:
at least one Mach-Zehnder modulator; and
a redundant semiconductor optical amplifier (SOA),
wherein the redundant SOA is connected to the at least one MZ modulator via a 2-input 2-output coupler,
the redundant SOA includes two SOAs arranged in parallel, and
the two SOAs are arranged in two waveguides connected to the 2-input 2-output coupler, respectively.
2 . The optical device according to claim 1 , wherein the redundant SOA is configured to switch the two SOAs to amplify light modulated by the at least one MZ modulator or light obtained before modulation.
3 . The optical device according to claim 1 , wherein the 2-input 2-output coupler is configured to distribute light modulated by the at least one MZ modulator to the two waveguides.
4 . The optical device according to claim 1 , wherein the 2-input 2-output coupler is configured to distribute light from the two waveguides to which the two SOAs are connected, to two arm waveguides of the at least one MZ modulator.
5 . The optical device according to claim 4 , further comprising a change-over switch configured to input light into one of the two waveguides to which the two SOAs are connected.
6 . The optical device according to claim 1 , further comprising a variable attenuator (VOA) connected to the redundant SOA.
7 . The optical device according to claim 1 , wherein the number of the at least one MZ modulator is two.
8 . The optical device according to claim 1 , wherein the number of the at least one MZ modulator is four and the 2-input 2-output coupler is a 2-input 2-output polarization beam combiner.