Ultra-compact, low-loss and high-speed optical phase shifter for high-speed modulation

This technology is an ultra-compact integrated optical phase shifter that enables low-loss, low-power and high-speed phase modulation for optical communications and computing applications.

Unmet Need: Compact, low-loss, low-power, high-speed phase shifters for integrated photonics

Integrated photonic systems require efficient phase shifters to enable high-speed optical communication and computing applications. However, existing phase modulation technologies face tradeoff between device size, optical loss, power consumption, and operating speed, limiting their scalability for dense photonic integration. Current solutions often require large device footprints or high operating power, making integration with compact silicon-based platforms challenging. There is a need for ultra-compact phase shifters that provide low-loss, low-power, and high-speed modulation without compromising device performance.

The Technology: 2D material-based optical phase shifter for high-speed modulation

This technology is an ultra-compact optical phase shifter that integrates 2D materials, including transition metal dichalcogenides (TMDs) and graphene, with a silicon nitride micro ring resonator. A voltage across the capacitor modulates both the index, via the electro-refractive response of the TMD, and the loss, via the electro-absorptive response of graphene, shifting the waveguide-ring coupling from under-coupled to over-coupled. The result is a strong, nearly pure phase shift with minimal amplitude modulation, in a footprint far smaller than conventional modulators and with nanowatt DC power. The platform also extends to other electro-optic materials, including TMDs such as MoS2, MoSe2, WS2, and MoTe2, silicon, indium gallium arsenide (InGaAs), and plasmonic materials. The technology has been experimentally validated, demonstrating high-speed phase modulation with 15 GHz electro-optic bandwidth, low insertion loss, and negligible amplitude modulation during binary phase-shift keying.

Applications:

• High-speed optical communications and data-center interconnects
• Optical switches and reconfigurable photonic integrated circuits
• Optical phased arrays and LIDAR beam steering
• Optical neural networks and photonic computing
• Optical memory, delay lines, and all-optical signal processing
• Quantum photonic circuits

Advantages:

• Ultra-compact design with a device length near 25 µm, far smaller than conventional phase modulators
• Low insertion loss with minimal amplitude modulation
• Low power operation with nanowatt-scale DC consumption from capacitive operation
• High speed modulation with an electro-optic bandwidth near 15 GHz
• Enables strong, nearly pure phase modulation for advanced optical communication formats
• Built on a low-loss silicon nitride platform with post-foundry, CMOS-compatible fabrication
• Material-agnostic design that extends to other TMDs and electro-optic materials

Lead Inventor:

Michal Lipson, Ph.D.

Patent Information:

Patent Pending (US20230296956)

Related Publications:

• Datta I, Gil-Molina A, Chae SH, Zhou V, Hone J, Lipson M. “2D material platform for overcoming the amplitude-phase tradeoff in ring resonators.” Optica. 2024; 11(1): 48-57.
• Datta I, Chae SH, Bhatt GR, et al. “Low-loss composite photonic platform based on 2D semiconductor monolayers.” Nat Photonics. 2020; 14: 256-262.
• Datta I, Jimenez Gordillo OA, Chae SH, Hone J, Lipson M. “Platform for electrically reconfigurable ring resonator based on TMD-graphene composite waveguides.” Conference on Lasers and Electro-Optics (CLEO). 2021; paper STh5B.1.

Tech Ventures Reference:

• IR CU21328

• Licensing Contact: [Greg Maskel] (mailto:techtransfer@columbia.edu)