Power-efficient integrated photonic switch
AssigneeJuniper Networks, Inc.
InventorJohn Parker
Life of this patent
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Abstract
Power consumption in MZI-based integrated photonic switches or filters throughout the operational life can be reduced by reducing fabrication-induced phase misalignment between the unpowered operational mode of the switch or filter and the predominant switch state, and/or by enabling low-power compensation for any such misalignment. In various embodiments, misalignment is reduced by increasing the width of the waveguides implementing the interferometer arms of the MZI, and/or by structuring a region containing the MZI symmetrically to diminish stress-induced misalignment. In some embodiments, phase tuners are used to actively compensate for any phase misalignment, with a tuner drive voltage substantially lower than used to switch to the non-dominant state.
Claims20
An integrated optical switch or filter comprising:
- a semiconductor-on-insulator substrate comprising a semiconductor device layer;
- a Mach-Zehnder interferometer formed in the semiconductor device layer, the Mach-Zehnder interferometer comprising an input coupler, an output coupler, and two waveguide arms connected between the input coupler and the output coupler;
- and
- at least a first phase tuner associated with one of the waveguide arms,
- wherein bend radii of the two waveguide arms are greater than 100 μm along entire lengths of the waveguide arms.
An integrated optical switch or filter comprising:
- a semiconductor-on-insulator substrate comprising a semiconductor device layer and a cladding layer disposed above the semiconductor device layer;
- a Mach-Zehnder interferometer formed in the semiconductor device layer, the Mach-Zehnder interferometer comprising an input coupler, an output coupler, and two waveguide arms connected between the input coupler and the output coupler;
- and
- a first phase tuner associated with one of the two waveguide arms and a second phase tuner associated with the other one of the two waveguide arms,
- wherein, within a symmetry region of the substrate that is centered about a geometric axis through the input coupler and the output coupler and that fully contains the Mach-Zehnder interferometer and the first and second phase tuners, the semiconductor device layer and cladding layer are structured symmetrically about the axis.
An integrated optical switch comprising:
- a semiconductor-on-insulator substrate comprising a semiconductor device layer;
- a Mach-Zehnder interferometer formed in the semiconductor device layer, the Mach-Zehnder interferometer comprising an input coupler, an output coupler, and two waveguide arms connected between the input coupler and the output coupler;
- a first phase tuner associated with one of the two waveguide arms and a second phase tuner associated with the other one of the two waveguide arms;
- and
- an electronic driver circuit comprising a first driver associated with the first phase tuner, a second driver associated with the second phase tuner, a microcontroller to control the first and second drivers to switch between biased and unbiased operational modes and to phase-align the two waveguide arms in the unbiased operational mode, and a buck converter to adjust, responsively to the microcontroller, a drive power supplied to the first and second phase tuners between a lower power for phase-aligning and a higher power in the biased operational mode.
An optical switching method comprising:
- coupling an optical input signal into a Mach-Zehnder interferometer formed in a semiconductor device layer of a semiconductor-on-insulator substrate;
- driving phase tuners associated with waveguide arms of the Mach-Zehnder interferometer to switch an optical output signal exiting the Mach-Zehnder interferometer at an output port between two states corresponding to biased and unbiased operational modes of the Mach-Zehnder interferometer, and to phase-align the waveguide arms in the unbiased operational mode;
- and
- using a buck converter to switch a drive power supplied to the phase tuners between a lower power for phase alignment in the unbiased operational mode and a higher power for operation in the biased operational mode.
Dependencies are inferred from the claim text.