Work

Compact, tunable microring resonator on a lithium niobate platform using etchless fabrication methods

Year: 2026

Type: article

Abstract: Tunable microring resonators on a lithium niobate on insulator (LNOI) platform are demonstrated, making use of thick polymer strip-loaded waveguides and bound states in the continuum (BIC) to achieve compact devices without plasma etching. The racetrack resonator device, with a bend radius of 94 μm , demonstrates strong confinement for TM-polarized modes, enabling electro-optic modulation with a modest half-wave voltage–length product of 35 Vcm . The device achieves a loaded quality factor of 4.17 × 10 4 for TM polarization and also supports purely linear TE modes with a loaded quality factor of 1.1 × 10 4 through guiding in the polymer layer. This etch-free process simplifies fabrication while maintaining access to lithium niobate’s χ (2) nonlinearity, offering a scalable route for photonic integrated circuits that combine reduced footprint, effective electro-optic performance with future potential for polarisation diversity on-chip.

Source: Optics Continuum

DOI: 10.1364/optcon.583515

Authors: Adnan Ghumro, Jack A. Smith, Loyd J. McKnight, Michael J. Strain

Language: English

Topic: Photonic and Optical Devices

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,372

Funders: Royal Academy of Engineering, Engineering and Physical Sciences Research Council

Award: Zero-change manufacturing of photonic interconnects for silicon electronics