Banded semiconductor optical amplifier

• US 8,964,284 B2
• Filed: 04/18/2012
• Issued: 02/24/2015
• 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.
• Primary Examiner(s): BOLDA, ERIC L
• Application Number:
  US13/449,515
• Publication Number:
  US 20130279910A1
• Time in Patent Office: 1,042 Days
• Field of Search: 359/344, 359/349
• US Class Current: 359/344
• 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 having only a first polarization and 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, the second polarization optical signal having only a second polarization,

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, such that the rotated first polarization optical signal only has the second polarization,

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 having only the second polarization 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 having only the second polarization 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, wherein the first polarization is a TM polarization and the second polarization is a TE polarization.

4. 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.

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

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

7. The optical amplifier of claim 1, where the wavelength beam splitter comprises a Mach-Zehnder interferometer.

8. The optical amplifier of claim 1, where the first rotator or the second rotator comprises an asymmetric waveguide or a photonic bandgap structure.

9. 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, one of the pair of polarized optical signals having a first polarization and the other of the pair of polarized optical signals having a second polarization;

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 the other optical signal of the pair of polarized optical signals to have the first polarization; 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;

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

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, the first of the pair of amplified and rotated polarized optical signals having only the first polarization; 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, the second of the pair of amplified and rotated polarized optical signals having only the first polarization,

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

10. The optical system of claim 9, further comprising a Raman amplifier configured to amplify the multiplexed optical signal or the amplified multiplexed optical signal.

11. The optical system of claim 9, where the first polarization is a Transverse Electric (TE) polarization and the second polarization is a Transverse Magnetic (TM) polarization.

12. The optical system of claim 9, 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.