US 11,714,238 B2Granted

Wavelength division multiplexing filter for multiplexing or demultiplexing using cascaded frequency shaping

AssigneeAnalog Photonics LLC

InventorsZhan Su, Erman Timurdogan

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Abstract

A wavelength division multiplexing filter comprises: a first multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers, and a second multi-order Mach-Zehnder interferometer comprising a plurality of first-order Mach-Zehnder interferometers; wherein the first multi-order Mach-Zehnder interferometer and the second multi-order Mach-Zehnder interferometer are included in a group of multiple multi-order Mach-Zehnder interferometers arranged within a binary tree arrangement, the binary tree arrangement comprising: a first set of a plurality of multi-order Mach-Zehnder interferometers, the first set including the first multi-order Mach-Zehnder interferometer, and having an associated spectral response with a first spacing between adjacent passbands, and a second set of at least twice as many multi-order Mach-Zehnder interferometers as in the first set, the second set including the second multi-order Mach-Zehnder interferometer, and having an associated spectral response with a second spacing between adjacent passbands that is twice the first spacing.

Claims9

Dependent claims

A method for fabricating a wavelength division multiplexing (WDM) filter for multiplexing or demultiplexing optical waves at wavelengths within different respective channels, the method comprising:

fabricating a first frequency shaping unit comprising:
two or more series-cascaded unit cells, each unit cell comprising a 2×2 coupler that cross couples two input ports to two output ports according to a predetermined coupling ratio connected to a phase delay component that imposes a relative phase delay between two paths according to a predetermined phase difference;
and
fabricating a second frequency shaping unit comprising:
two or more series-cascaded unit cells, each unit cell comprising a 2×2 coupler that cross couples two input ports to two output ports according to a predetermined coupling ratio connected to a phase delay component that imposes a relative phase delay between two paths according to a predetermined phase difference;
wherein a first set of two or more frequency shaping units, including the first frequency shaping unit, have an associated spectral response with a first spacing between adjacent passbands, and the relative phase delays and coupling ratios of the first frequency shaping unit are selected based at least in part on material and modal refractive index dispersion to provide at least one substantially flat passband in the spectral response associated with the first frequency shaping unit;
and
wherein a second set of two or more frequency shaping units, including the second frequency shaping unit, have an associated spectral response with a second spacing between adjacent passbands that is twice the first spacing, and the relative phase delays and coupling ratios of the second frequency shaping unit are selected based at least in part on material and modal refractive index dispersion to provide at least one substantially flat passband in the spectral response associated with the second frequency shaping unit.

5 more elements

A wavelength division multiplexing (WDM) transceiver system supporting optical waves at wavelengths within different respective channels, the WDM transceiver system comprising:

a first transmitter subsystem comprising:
a first WDM multiplexer comprising a plurality of multi-order Mach-Zehnder interferometers that each comprise a plurality of first-order Mach-Zehnder interferometers,
a plurality of optical sources and/or ports providing optical waves at a plurality of wavelengths, and
a plurality of optical modulators configured to modulate the optical waves and provide modulated optical waves to the first WDM multiplexer;
and
a first receiver subsystem comprising:
a first WDM demultiplexer comprising a plurality of multi-order Mach-Zehnder interferometers that each comprise a plurality of first-order Mach-Zehnder interferometers,
a second WDM demultiplexer comprising a plurality of multi-order Mach-Zehnder interferometers that each comprise a plurality of first-order Mach-Zehnder interferometers,
a polarization-sensitive splitter configured to provide a first input optical wave to the first WDM demultiplexer and a second input optical wave to the second WDM demultiplexer;
a tuning module comprising:
a plurality of photodetectors configured to monitor power before and after the first WDM multiplexer, before and after the first WDM demultiplexer, and before and after the second WDM demultiplexer, and
circuitry configured to tune center wavelengths of the channels based at least in part on adjusting relative optical output power from each output port of each of a plurality of the first-order Mach-Zehnder interferometers in the first WDM multiplexer first WDM demultiplexer, and second WDM demultiplexer.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/569,878Filed 6 Jan 2022 · division
Priority: 8 Apr 2019
Published: US 2022/0137299 A15 May 2022
Granted: 1 Aug 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

G02B 6/29355
In a light guide: cascade arrangement of interferometers
G02B 6/12007
Of the integrated circuit kind: forming wavelength selective elements, e.g. multiplexer, demultiplexer
G02B 6/2935
Operating by wave or beam interference: mach-Zehnder configuration, i.e. comprising separate splitting and combining means
G02B 6/29368
Interference filters, e.g. multilayer coatings, thin film filters, dichroic splitters or mirrors based on multilayers, WDM filters: light guide…

Family

Application62/830,653Us provisional application · filed 8 Apr 2019
Application16/843,027Parent of this division · filed 8 Apr 2020
US 2022/0137299 A1Pre-grant publication · published 5 May 2022
US 11,249,254 B2Parent of this division
US 2020/0319409 A1Published application
US 11,714,238 B2This patent

From the US filing history. Foreign family members aren’t listed.