Ultra-high-linearity integrated lithium niobate electro-optic modulators

Abstract

Integrated lithium niobate (LN) photonics is a promising platform for future chip-scale microwave photonics systems owing to its unique electro-optic properties, low optical loss, and excellent scalability. A key enabler for such systems is a highly linear electro-optic modulator that could faithfully convert analog electrical signals into optical signals. In this work, we demonstrate a monolithic integrated LN modulator with an ultra-high spurious-free dynamic range (SFDR) of 120.04 dB · Hz 4 / 5 at 1 GHz, using a ring-assisted Mach–Zehnder interferometer configuration. The excellent synergy between the intrinsically linear electro-optic response of LN and an optimized linearization strategy allows us to fully suppress the cubic terms of third-order intermodulation distortions (IMD3) without active feedback controls, leading to ∼ 20 dB improvement over previous results in the thin-film LN platform. Our ultra-high-linearity LN modulators could become a core building block for future large-scale functional microwave photonic integrated circuits by further integration with other high-performance components like low-loss delay lines, tunable filters, and phase shifters available on the LN platform.

Ultrahigh dynamic range and low noise figure programmable integrated microwave photonic filter

“…Applications of MWP systems usually require ultra-high SFDR of beyond 120 dB Hz 2/3 15 . Although such a metric can be achieved through linearization of the modulator transfer function 37 – 40 , it remains challenging to achieve linearization simultaneously with functionalities. Here, we demonstrate simultaneous RF notch filter and linearization by using the combination of MT and DI-RR circuits in the same photonic chip.…”

Perspective on Lithium-Niobate-on-Insulator Photonics Utilizing the Electro-optic and Acousto-optic Effects

“…In addition, the linearity of LN modulators is excellent as the Pockels effect in LN is intrinsically linear. The highest spurious free dynamic range (SFDR) for modulators on LNOI is ∼120 dB·Hz, which is complemented using a ring-assisted Mach–Zehnder interferometer configuration …”

Ultrahigh Dynamic Range and Low Noise Figure Programmable Integrated Microwave Photonic Filter

“…Applications of MWP systems usually require ultra-high SFDR of beyond 120 dB Hz 2/315 . Although such a metric can be achieved through linearization of the modulator transfer function [37][38][39][40] , it remains challenging to achieve linearization simultaneously with functionalities. Here, we demonstrate simultaneous RF notch filter and linearization by using the combination of MT and DI-RR circuits in the same photonic chip.…”