Banded Semiconductor Optical Amplifier

• US 20130279910A1
• Filed: 04/18/2012
• Published: 10/24/2013
• Est. Priority Date: 04/18/2012
• Status: Active Grant

• Current Assignee: Infinera Corp.
• Original Assignee: Infinera Corp.
• Inventors: Ziari, Mehrdad, Corzine, Scott, Kato, Masaki, Van Leeuwen, Michael Francis, Nagarajan, Radhakrishnan L., Mitchell, Matthew L., Kish, Fred A. Jr.
• Granted Patent: US 8,964,284 B2
• Time in Patent Office: Days
• US Class Current: 398/65
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength
• CPC Class Codes: H01S 5/5009 the arrangement being polarisation-insensitive
• CPC Class Codes: H01S 5/5036 the arrangement being polarisation-selective
• CPC Class Codes: H01S 5/5045 the arrangement having a frequency filtering function
• CPC Class Codes: H04B 10/2914 using lumped semiconductor optical amplifiers [SOA]
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04J 14/06 Polarisation multiplex systems

Abstract

A semiconductor optical amplifier module may include a beam splitter to split an optical signal into two polarization optical signals including a first polarization optical signal with a Transverse Magnetic (TM) polarization provided along a first path of two paths, and a second polarization optical signal with a Transverse Electric (TE) polarization provided along a second path of the two paths; a first rotator to rotate the TM polarization of the first polarization optical signal to TE polarization; a first semiconductor optical amplifier to amplify the rotated first polarization optical signal to output a first resultant optical signal; a second semiconductor optical amplifier to amplify the second polarization optical signal; and a second rotator to rotate the polarization of the amplified second polarization optical signal to output a second resultant optical signal; and a beam combiner to combine the first resultant optical signal and the second resultant optical signal.

Claims

1. An optical amplifier comprising:

a substrate;

a wavelength band splitter on the substrate, the wavelength band splitter configured to split an optical signal into a plurality of banded optical signals of particular wavelength bands;

a plurality of semiconductor optical amplifier modules on the substrate, each of the plurality of semiconductor optical amplifier modules configured to amplify one of the plurality of banded optical signals of the particular wavelength bands from the wavelength band splitter into an amplified banded optical signal, and each of the plurality of semiconductor optical amplifier modules comprising;

a polarized beam splitter configured to split the one of the plurality of banded optical signals into two polarization optical signals, a first polarization optical signal of the two polarization optical signals being provided along a first path of two separate optical paths, and a second polarization optical signal of the two polarization optical signals being provided along a second path of the two separate optical paths,

a first rotator along the first path, the first rotator configured to rotate a polarization of the first polarization optical signal to obtain a rotated first polarization optical signal,

a first semiconductor optical amplifier configured to amplify the rotated first polarization optical signal to obtain an amplified first polarization optical signal,

a first variable optical attenuator configured to adjust a power level, a phase, and/or an amplitude level of the amplified first polarization optical signal to output a first resultant optical signal,

a second semiconductor optical amplifier configured to amplify the second polarization optical signal to obtain an amplified second polarization optical signal,

a second variable optical attenuator configured to adjust a power level, a phase, and/or an amplitude level of the amplified second polarization optical signal to obtain an adjusted second polarization optical signal,

a second rotator along the second path, the second rotator configured to rotate the polarization of the adjusted second polarization optical signal to output a second resultant optical signal, and

a polarized beam combiner configured to combine the first resultant optical signal and the second resultant optical signal into the amplified banded optical signal; and

a wavelength band combiner on the substrate, the wavelength band combiner configured to combine the amplified banded optical signals from each of the plurality of semiconductor optical amplifier modules into an amplified optical signal.

2. The optical amplifier of claim 1, where the wavelength band splitter comprises a bandpass filter configured to receive the optical signal, the optical signal having multiple wavelengths, and where the bandpass filter is configured to split the optical signal into a plurality of banded optical signals in one or more of O-band, E-band, S-band, C-band, L-band, or U-band.

3. The optical amplifier of claim 1, where the polarized beam splitter is configured to:

split the one of the plurality of banded optical signals into a Transverse Magnetic (TM) polarization optical signal and a Transverse Electric (TE) polarization optical signal;

provide the TM polarization optical signal to the first path; and

provide the TE polarization optical signal to the second path,

where the first polarization optical signal is the TM polarization optical signal,

where the second polarization optical signal is the TE polarization optical signal.

4. The optical amplifier of claim 3, where the first semiconductor optical amplifier is configured to amplify the TE polarization optical signal along the first path, and

where the second semiconductor optical amplifier is configured to amplify a second TE polarization optical signal along the second path, where the second TE polarization optical signal along the second path was rotated by the second rotator from TM polarization to TE polarization.

5. The optical amplifier of claim 3, where along the first path, the first polarization optical signal has TE polarization, the rotated first polarization optical signal has TM polarization, and the first resultant optical signal has TM polarization,

where along the second path, the second polarization optical signal has TM polarization, the amplified second polarization optical signal has TM polarization, and the second resultant optical signal has TE polarization, and

where the polarized beam combiner is configured to combine the first resultant optical signal with TE polarization and the second resultant optical signal with TM polarization into an unpolarized amplified banded optical signal.

6. The optical amplifier of claim 1, where the first or the second variable optical attenuator comprises a Mach-Zehnder interferometer, and where:

the first variable optical attenuator is configured to adjust the power level, the phase, and/or the amplitude level of the amplified first polarization optical signal to balance with the power level, the phase, and/or the amplitude level of the amplified second polarization optical signal, or

the second variable optical attenuator is configured to adjust the power level, the phase, and/or the amplitude level of the amplified second polarization optical signal to balance with the power level, the phase, and/or the amplitude level of the amplified first polarization optical signal.

7. The optical amplifier of claim 1, where the polarized beam combiner comprises a thin-film polarizer.

8. The optical amplifier of claim 1, where the wavelength band combiner comprises an optical filter or an arrayed waveguide grating (AWG).

9. A semiconductor optical amplifier module comprising:

a beam splitter configured to split an optical signal into two polarization optical signals to provide along two paths, the two polarization optical signals including a first polarization optical signal with a Transverse Magnetic (TM) polarization provided along a first path of the two paths, and a second polarization optical signal with a Transverse Electric (TE) polarization provided along a second path of the two paths;

a first rotator along the first path, the first rotator configured to rotate the TM polarization of the first polarization optical signal to TE polarization;

a first semiconductor optical amplifier along the first path, the first semiconductor optical amplifier configured to amplify the rotated first polarization optical signal with TE polarization to output a first resultant optical signal;

a second semiconductor optical amplifier along the second path, the second semiconductor amplifier configured to amplify the second polarization optical signal with TE polarization; and

a second rotator along the second path, the second rotator configured to rotate the polarization of the amplified second polarization optical signal to output a second resultant optical signal with TM polarization; and

a beam combiner configured to combine the first resultant optical signal with TE polarization from the first path and the second resultant optical signal with TM polarization from the second path into an optical signal.

10. The semiconductor optical amplifier module of claim 9, where the beam splitter comprises a Mach-Zehnder interferometer.

11. The semiconductor optical amplifier module of claim 9, where the first rotator or the second rotator comprises an asymmetric waveguide or a photonic bandgap structure.

12. The semiconductor optical amplifier module of claim 9, further comprising:

a first device configured to adjust a power level, a phase, and/or an amplitude level of the first resultant optical signal before the first resultant optical signal is output to the beam combiner; and

a second device configured to adjust a power level, a phase, and/or an amplitude level of the second resultant optical signal before the second resultant optical signal is output to the beam combiner,

where the first device or the second device comprises a Mach-Zehnder interferometer.

13. The semiconductor optical amplifier module of claim 9, further comprising a substrate, where the beam splitter, the first rotator, the first semiconductor optical amplifier, the second semiconductor optical amplifier, the second rotator, and the beam combiner are on the substrate.

14. An optical system comprising:

a plurality of transmitters configured to transmit a plurality of transmitted optical signals;

a multiplexer configured to receive and combine the plurality of transmitted optical signals into a multiplexed optical signal;

a plurality of optical amplifiers configured to amplify the multiplexed optical signal, one of the plurality of optical amplifiers comprising;

a wavelength band splitter, the wavelength band splitter configured to split the multiplexed optical signal into a plurality of banded optical signals of particular wavelength bands;

a plurality of modules configured to communicate with the wavelength band splitter and receive at least one of the plurality of banded optical signals, each of the plurality of modules configured to amplify one of the plurality of banded optical signals of the particular wavelength bands from the wavelength band splitter into an amplified banded optical signal, and one of the plurality of modules comprising;

a polarized beam splitter to split one of the plurality of banded optical signals into a pair of polarized optical signals;

a plurality of semiconductor optical amplifiers each of which is configured to amplify an optical signal of the pair of polarized optical signals;

a plurality of rotators each of which is configured to rotate an optical signal of the pair of polarized optical signals; and

a polarized beam combiner to combine the pair of amplified and rotated polarized optical signals into the amplified banded optical signal; and

a wavelength band combiner on the substrate, the wavelength band combiner configured to combine the amplified banded optical signals from each of the plurality of modules into an amplified multiplexed optical signal;

a demultiplexer configured to decombine the amplified multiplexed optical signal into a plurality of amplified demultiplexed optical signals; and

a plurality of receivers configured to receive the plurality of amplified demultiplexed optical signals.

15. The optical system of claim 14, further comprising a Raman amplifier configured to amplify the multiplexed optical signal or the amplified multiplexed optical signal.

16. The optical system of claim 14, where the polarized beam splitter of the one of the plurality of banded semiconductor optical amplifiers is configured to:

split the one of the plurality of banded optical signals into a Transverse Magnetic (TM) polarization optical signal and a Transverse Electric (TE) polarization optical signal;

provide the TM polarization optical signal to a first path; and

provide the TE polarization optical signal to a second path.

17. The optical system of claim 16, where a first rotator, of the plurality of rotators, on the first path is configured to rotate the TM polarization optical signal on the first path to a TE polarization,

where a first semiconductor optical amplifier, of the plurality of semiconductor optical amplifiers, on the first path is configured to amplify the TE polarization optical signal along the first path, and

where the second semiconductor optical amplifier, of the plurality of semiconductor optical amplifiers, on the second path is configured to amplify the TE polarization optical signal along the second path.

18. The optical system of claim 16, where the first path has a first polarization optical signal initially with TM polarization, which is rotated to TE polarization by a first rotator, of the plurality of rotators, on the first path, and the rotated first polarization optical signal is amplified by a first semiconductor optical amplifier, of the plurality of semiconductor optical amplifiers, on the first path, and

where the second path has a second polarization optical signal initially with TE polarization, which is amplified by a second semiconductor optical amplifier, of the plurality of semiconductor optical amplifiers, on the second path, and the amplified second polarization optical signal is rotated by a second rotator, of the plurality of rotators, on the second path to TM polarization, and

where the polarized beam combiner is configured to combine the amplified rotated first polarization optical signal with TE polarization and the rotated amplified second optical signal with TM polarization into an unpolarized amplified optical signal.

19. The optical system of claim 14, where the one of the plurality of modules further comprises:

a first device configured to adjust a power level, a phase, and/or an amplitude level of a first of the pair of amplified and rotated polarized optical signals before the first of the pair of amplified and rotated polarized optical signals is output to the polarized beam combiner; and

a second device configured to adjust a power level, a phase, and/or an amplitude level of a second of the pair of amplified and rotated polarized optical signals before the second of the pair of amplified and rotated polarized optical signals is output to the polarized beam combiner,

where the first device or the second device comprises a Mach-Zehnder interferometer.

20. The optical system of claim 14, where the wavelength band splitter comprises a bandpass filter configured to receive the multiplexed optical signal, the multiplexed optical signal having a plurality of wavelengths with a plurality of polarities, and where the bandpass filter is configured to split the multiplexed optical signal into a plurality of wavelength bands including one or more of O-band, E-band, S-band, C-band, L-band, or U-band, and

where the wavelength band combiner comprises an optical filter or an arrayed waveguide grating (AWG) configured to combine the amplified banded optical signals from each of the plurality of modules, the amplified banded optical signals including amplified banded optical signals corresponding to multiple wavelength bands including one or more of the O-band, the E-band, the S-band, the C-band, the L-band, or the U-band.