Ciena Corporation

Alexandre Delisle-Simard

Michel Poulin

Yves Painchaud

Michael Vitic

Christine Latrasse

Charles Baudot

Arash Khajooeizadeh

François Pelletier

Ian B Betty

Christopher Edgar Falt

Marie-Josée Picard

Sean Sebastian O'Keefe

Marie-Josee Picard

Antoine Bois

Ian Betty

Gregory Brookes

An optical modulator includes an optical waveguide extending a length; and a plurality of Radio Frequency (RF) electrodes configured to modulate an optical signal in the optical waveguide, wherein the RF electrodes include an RF crossing located an end of the length and that is configured to equalize the optical signal. The optical signal is equalized via destructive interference after the RF crossing for attenuating modulation amplitude. At or near the end of the length, high frequencies of the optical signal are already strongly attenuated whereas low frequencies of the optical signal are not such that the low frequencies are equalized after the RF crossing.

RF crossing in an optical modulator for equalization

An optical modulator includes a waveguide core; a first transition zone located between a first side of the waveguide core and a first electrical contact region; and a second transition zone located between a second side of the waveguide core and a second electrical contact region, wherein one or more of the first transition zone and second transition zone has a variable thickness. The variable thickness is confined to the one or more of the first transition zone and second transition zone. The variable thickness removes a portion of the highly doped first transition zone and the highly doped second transition zone thereby reducing contact resistance.

Silicon-based modulator with different transition zone thicknesses

A carrier depletion-based Silicon Photonic (SiP) modulator using capacitive coupling includes a high-k dielectric material in or on slabs, between a rib. A capacitance (C) of the high-k dielectric material is larger than a capacitance (C) of the rib, thereby reducing the high frequency impedance and improving bandwidth of the modulator. A modulator includes a first electrode; a first slab connected to the first electrode at a first end; a rib connected to the first slab at a second end of the first slab; a second slab connected to the rib at a first end; a second electrode connected to the second slab at a second end of the second slab; and a high-k dielectric material disposed in or on a portion of each of the first slab and the second slab, thereby enabling capacitive coupling.

Carrier depletion-based silicon photonic modulator using capacitive coupling

An optical modulator includes a first Radio Frequency (RF) line and a second RF line; an optical waveguide along a length of the modulator with an input and an output; and a plurality of segments along the length including a first set of segments, a single RF line crossing, and a second set of segments, wherein the first set of segments and the second set of segments have an inversion of their respective orientation at the RF line crossing, and wherein the RF line crossing is located off center relative to the plurality of segments, wherein each of the first RF line and the second RF line extend along the length and cross one another at the RF line crossing.

Optical modulator robust to fabrication errors through an RF electrical crossing

A first transmission line comprises a first pair of electrodes receiving an electrical drive comprising first and second drive signals, which are loaded by a first series of p-n junctions applying optical phase modulation to respective optical waves propagating over a first section of the first and second optical waveguide arms of an MZI. A second transmission line comprises a second pair of electrodes configured to receive the electrical drive after an electrical signal delay. The second pair of electrodes are loaded by a second series of p-n junctions applying optical phase modulation to the respective optical waves propagating over a second section of the first and second optical waveguide arms after propagation over the first section. An electrode extension structure provides the electrical drive to the second pair of electrodes, and comprises an unloaded transmission line portion imposing the electrical signal delay based on an optical signal delay.

Providing a drive signal for optical modulator portions

A loss-based wavelength meter includes a first photodiode configured to measure power of monochromatic light; and a loss section having a monotonic wavelength dependency, wherein a wavelength of the monochromatic light is determined based on measurements of the first photodiode after the monochromatic light has gone through the loss section. This provides a compact implementation that may be used in integrated optics devices using silicon photonics as well as other embodiments.

Loss-based wavelength meter

A silicon modulator where the doping profile varies along the lateral and/or longitudinal position in the transition zones to achieve improved performance in terms of either optical attenuation or contact access resistance or both. A silicon-based modulator includes a waveguide including a contact region and a core region, wherein the waveguide includes a dopant concentration that decreases from the contact region to the core region in a transition zone according to a doping profile that is variable.

Silicon-based modulator with optimized doping profile

Driving an optical modulator is described. A control circuit generates first and second input voltages based on a target phase modulation between first and second optical waveguide arms of the optical modulator. An offset control circuit generates first and second offset signals. A linear modulator driver receives the first and second offset signals, generates a first output voltage for biasing the first optical waveguide arm using the first offset signal, and generates a second output voltage for biasing the second optical waveguide arm using the second offset signal. Feedback circuitry can feed the first and second output voltages to the offset control circuit, which can generate the first and second offset signals using the first and second output voltages. The output voltages bias the waveguide arms so the optical modulator operates close to the target phase modulation, even in the presence of manufacturing errors.

Apparatus and method for driving an optical modulator with independent modulator arm bias

A method of Silicon Selective Epitaxial Growth (SEG) applied to a Silicon on Insulator (SOI) wafer to provide a first region of customized thickness includes with the SOI wafer having a standard thickness, applying a hard mask to a plurality of regions of the SOI wafer including the first region; applying photo-lithography protection to cover the hard mask in all of the plurality of regions except the first region; removing the hard mask in the first region; and performing Silicon SEG in the first region to provide the customized thickness in the first region, wherein the customized thickness is greater than the standard thickness.

Silicon Selective Epitaxial Growth (SEG) applied to a Silicon on Insulator (SOI) wafer to provide a region of customized thickness

An optical modulator includes multiple segments including modulator segments and a Radio Frequency (RF) crossing segment where RF lines extending a length of the modulator cross one another. The present disclosure includes optimization of one or more of a geometry of the RF crossing and a location of the RF crossing segment along the length. The geometry is selected so that the RF crossing segment appears as another segment having similar characteristics as modulator segments. The location of the RF crossing segment is selected to balance out fabrication error and phase efficiency.

A silicon modulator where the doping profile varies along the lateral and/or longitudinal position in the transition zones to achieve improved performance in terms of optical attenuation or contact access resistance or both. A modulator includes a core; a first transition zone that is a P-side region adjacent to the waveguide core, the first transition zone has a first longitudinal doping profile; and a second transition zone that is an N-side region adjacent to the core on an opposite side as the first transition region, the second transition zone has a second longitudinal doping profile; the first longitudinal doping profile has a variation of doping concentration along a longitudinal direction in the first transition region to mimic a first lateral doping profile, and the second longitudinal doping profile has a variation of doping concentration along a longitudinal direction in the second transition region to mimic a second lateral doping profile.

Silicon-based modulator with optimized longitudinal doping profiles

The present disclosure provides a multi-pass free-carrier absorption variable optical attenuator device, including: a diode structure including a P-type doped region and an N-type doped region separated by an intrinsic region; and an optical waveguide including a plurality of optical waveguide sections aligned parallel to one another and disposed between the P-type doped region and the N-type doped region and within the intrinsic region of the diode structure. Further, the present disclosure provides a multi-pass thermal phase shifter device, including: a silicon structure including or coupled to one or more heater elements; and an optical waveguide including a plurality of optical waveguide sections aligned parallel to one another and disposed adjacent to the one or more heater elements. Optionally, at least two of the optical waveguide sections have different geometries and are separated by a predetermined gap.

Free-carrier absorption variable optical attenuators and thermal phase shifters formed by an optical waveguide having multiple passes in an intrinsic region

A silicon modulator where the doping profile varies along the lateral and/or longitudinal position in the transition zones to achieve improved performance in terms of either optical attenuation or contact access resistance or both. A silicon-based modulator includes a waveguide core that is a PN junction region; a first transition zone that is a P-side region adjacent to the waveguide core and a first electrode; and a second transition zone that is an N-side region adjacent to the waveguide core on an opposite side as the first transition region and a second electrode; wherein a thickness of each of the first transition zone and the second transition zone is variable in any of a lateral direction, a longitudinal direction, and both the lateral direction and the longitudinal direction, each of the lateral direction and the longitudinal direction are relative to the waveguide core.

A waveguide coupling structure includes: a first section that supports a mode that has an associated first intensity profile that substantially overlaps with an intensity profile associated with a mode supported by a first waveguide portion at a first end of the waveguide coupling structure; a second section that supports a mode that has an associated second intensity profile that substantially overlaps with an intensity profile associated with a mode supported by a second waveguide portion at a second end of the waveguide coupling structure; and a third section, between the first section and the second section, comprising a core structure on a bottom cladding and a supporting structure on the bottom cladding. The supporting structure: (1) overlaps with at least a portion of an intensity profile associated with a guided mode of the third section, and (2) has a shape that is asymmetric with respect to a propagation axis of the guided mode in a plane parallel to a surface of the bottom cladding.

Managing mode transfer in asymmetric waveguide coupling structures

An optical modulator device and method, including and utilizing: a first optical waveguide arm including one or more optical phase shifters, e.g., pn junctions, and configured to receive a first bias voltage V; and a second optical waveguide arm including one or more optical phase shifters, e.g., pn junctions, and configured to receive a second bias voltage V; wherein the first bias voltage Vand the second bias voltage Vare dissimilar, such that the first optical waveguide arm and the second optical waveguide arm exhibit a same phase modulation. Vand Vare selected such that the corresponding slopes V&#x3c0; of the associated phase shift versus applied bias voltage curves are equal. The optical modulator device further includes a driver coupled to the first optical waveguide arm and the second optical waveguide arm and including a current offset control circuit operable for providing Vand V.

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Québec, Canada

Alexandre Delisle-Simard