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Stirring the PIC Pot: TFLN and BTO Add New Flavour to the Wafer Menu (Category: PIC)

  • Writer: Nicholas Gagnon
    Nicholas Gagnon
  • Sep 29
  • 3 min read

Updated: Oct 5

SiN Wafer, courtesy imec (image)
SiN Wafer, courtesy imec (image)

I conducted some research to revisit the Canadian PIC ecosystem—particularly its intersection with quantum computing and sensing—to update my understanding from three years ago, when I was most deeply immersed in the PIC domain. My goal was to identify emerging trends, materials, and innovations shaping the current landscape.

A few years ago, PIC fabrication primarily relied on Silicon, Silicon Nitride (Si₃N₄), and Lithium Niobate (LiNbO₃). As a Dutch friend once reminded me, “No single integrated-photonics technology can do it all.” That wisdom still holds today—especially when integrating laser sources—making hybrid and heterogeneous integration increasingly vital.


Key Findings and Innovations


1. Thin-Film Lithium Niobate (TFLN): A Rising Star

TFLN appears to be becoming foundational for next-gen PICs, particularly in high-speed, low-loss, and nonlinear applications. Canada is actively investing in this space:

  • FABrIC Initiative: Supported by Canada’s Strategic Innovation Fund (SIF), this program is establishing a national TFLN prototyping and fabrication capacity.

    • Lead: INO (Québec City)

    • Co-Leads: EXFO (Québec City), C2MI (Bromont), AEPONYX (Montreal, now part of Pasqual)

    • Partner: CMC Electronics (Photonics team, Montreal)


TFLN Advantages:

Feature

Benefit

Electro-Optic Coefficient

Among the highest, enabling ultra-fast, low-voltage modulation

Optical Loss

<0.1 dB/cm in optimized waveguides advertised (Xanadu claim 2dB/m in TFLN performance)

Transparency Window

Visible to mid-IR; ideal for quantum optics and biosensing

Nonlinear Efficiency

Excellent for SHG and parametric processes

CMOS Compatibility

Enables hybrid integration with silicon photonics

Environmental Stability

Suitable for field-deployed and high-power systems


Application Highlights:

  • Quantum photonics: entanglement and gate modulation

  • Optical communications: high-speed modulators

  • LiDAR/sensing: precision phase control

  • RF photonics: electro-optic mixing


2. Xanadu: Pushing the Boundaries of Fault-Tolerant Quantum Computing

Xanadu continues to impress with its modular, room-temperature quantum photonic chips. In June 2025, they announced a new Advanced Photonic Packaging Facility in Toronto.

Their architecture leverages:

  • Squeezed-state photonics

  • Nonlinear optics

  • Heterogeneous integration across multiple wafer platforms


Wafer Materials in Use:

Material

Role

Rationale

Silicon

Passive photonic platform

CMOS-compatible and scalable

Si₃N₄

Low-loss routing

Ideal for squeezed light and single photons

LiNbO₃ → TFLN

Modulation

Fast phase shifting for quantum gates

Barium Titanate (BTO)

Electro-optic phase shifters

High-speed, low-voltage switching

Notably, AEPONYX (Pasqual)—a co-lead in the FABrIC TFLN initiative—appears to be aligning its fault-tolerant quantum computing strategy with TFLN.


BTO vs. TFLN: Electro-Optic Materials for Quantum PICs

Feature

BTO

TFLN

Electro-Optic Efficiency

Higher (~10⁻⁴ V⁻¹)

Moderate (~10⁻⁵ V⁻¹)

Frequency Response

Tunable, frequency-dependent

Stable across a wide range

Modulation Bandwidth

>100 GHz

>110 GHz in hybrid platforms

Wafer Size

300 mm (PsiQuantum)

150–200 mm typical

Fabrication Maturity

Emerging

Commercially mature

Integration Complexity

High

Easier with Si/Si₃N₄

Quantum PIC Suitability

Ultra-efficient switching

Scalable, stable modulation

  • BTO: Ideal for ultra-fast switching but limited by fabrication maturity and integration complexity.

  • TFLN: Slightly less efficient but offers broader stability, easier integration, more maturity and scalable fabrication.


PIC Wafer Material Market Share (2024 Estimates)

Material

Market Share (%)

Notes

III-V Semiconductors (InP, GaAs)

~30–35%

Dominant for laser integration

Silicon

~30–35%

Backbone of silicon photonics

Silicon Nitride (Si₃N₄)

~15–20%

Preferred for low-loss routing

Lithium Niobate (LiNbO₃ / TFLN)

~5–10%

Rapid growth in modulators and nonlinear optics

Group IV Semiconductors (Ge, SiGeSn)

<5%

Niche, emerging

Barium Titanate (BTO)

<1%

Experimental, research-focused

Key Takeaways

  • III-V materials remain essential for laser sources.

  • Silicon and Si₃N₄ dominate passive and hybrid platforms.

  • TFLN is gaining momentum due to its electro-optic and integration advantages.

  • BTO and Group IV materials show promise but are not yet mainstream.


Have ideas or feedback? Drop me a line at nicholas@aheadcurve.co

 
 
 

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