US 12,650,629 B2Granted

Apparatus and method for intensity modulation in a photonic computing system based on interferometric coupling

AssigneeHuawei Technologies Canada Co., Ltd.

InventorsEnxiao Luan, Armaghan Eshaghi

Life of this patent

Estimating the term…

Loading patent…

Abstract

A waveguide is coupled at both ends to a microring (MRR) modulator in order to form a Mach-Zehnder interferometer out of the resulting unit. The coupled waveguide can be modulated independently from the MRR modulator itself with either an in-resonance photoconductive heater or a geometrically suitable PN junction. During modulation with an applied voltage to the coupler, an independent modulation can be applied to the MRR in order to compensate for wavelength shifting. Ideal lengths for the coupler are identified, as well as a spiral configuration to reduce the coupler's footprint on a photonic integrated circuit. The resulting device has reduced cross-talk between channels of a cascaded MRR system. A second coupler can be coupled to each MRR symmetrically so as to reduce insertion losses, allowing for an increased weight range at the drop and through ports.

Claims18

Dependent claims

A photonic device comprising:

a ring waveguide;
a first waveguide coupled to the ring waveguide at a first site and a second site,
the first waveguide having:
a first section extending from the first site;
a second section extending from the second site;
and
a first middle section located between the first section and the second section and extending between the first site and the second site, the first middle section being further from the ring waveguide than the first site and the second site;
a second waveguide coupled at to the ring waveguide at a third site and a fourth site, the second waveguide having:
a third section extending from the third site;
a fourth section extending from the fourth site;
and
a second middle section located between the third section and the fourth section and extending between the third site and the fourth site, the second middle section being further from the ring waveguide than the third site and the fourth site;
a first control element operatively coupled to the first middle section;
a second element control operatively coupled to the second middle section;
and
a further control element operatively coupled to the ring waveguide;
and
a controller configured to operate the first control element and the second control element to adjust an extinction ratio of the photonic device at a resonant wavelength, and to simultaneously operate the further control element to counteract a shift in the resonant wavelength induced by the operation of the first control element and of the second control element, thereby maintaining the resonant wavelength at a substantially constant value during said adjustment of the extinction ratio.

15 more elements

A photonic device comprising:

a ring waveguide;
a first waveguide coupled to the ring waveguide at a first site and a second site, the first waveguide having:
a first section extending from the first site;
a second section extending from the second site;
and
a first middle section located between the first section and the second section and extending between the first site and the second site, the first middle section being further from the ring waveguide than the first site and the second site;
a first control element operatively coupled to the first middle section;
a further control element operatively coupled to the ring waveguide;
and
a controller configured to operate the first control element to adjust an extinction ratio of the photonic device at a resonant wavelength, and to simultaneously operate the further control element to counteract a shift in the resonant wavelength induced by the operation of the first control element, thereby maintaining the resonant wavelength at a substantially constant value during said adjustment of the extinction ratio,
wherein the first middle section and the first control element interface along an extended portion of the first middle section having a length, said length being configured to provide for a coupling efficiency, of the first control element, which is sufficient to control an amount of optical power coupled from the first waveguide to the ring waveguide between a minimum value and a maximum value, the minimum value being substantially zero and the maximum value being substantially equal to all of optical power input to the photonic device.

8 more elements

A photonic device comprising:

a ring waveguide;
a first waveguide coupled to the ring waveguide at a first site and a second site, the first waveguide having:
a first section extending from the first site;
a second section extending from the second site;
and
a middle section located between the first section and the second section and extending between the first site and the second site, the middle section being further from the ring waveguide than the first site and the second site;
a first control element operatively coupled to the middle section;
a further control element operatively coupled to the ring waveguide;
and
a controller configured to operate the first control element to adjust an extinction ratio applied by the photonic device at a resonant wavelength of the photonic device, and to simultaneously operate the further control element to counteract a shift in the resonant wavelength induced by the operation of the first control element, thereby maintaining the resonant wavelength at a substantially constant value during said adjustment of the extinction ratio.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/212,515Filed 21 Jun 2023 · continuation
Priority: 25 Jan 2021
Published: US 2023/0333441 A119 Oct 2023
Granted: 9 Jun 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

G02F 1/0305
Based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect: constructional arrangements
G02F 1/2257
In an optical waveguide structure: the optical waveguides being made of semiconducting material
G02F 1/0147
For the control of the intensity, phase, polarisation or colour: based on thermo-optic effects
G02F 1/025
Based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction: in an optical waveguide structure