Breaking the bandwidth limit of a high-quality-factor ring modulator based on thin-film lithium niobate

Abstract

Growing global data traffic requires high-performance modulators with a compact size, a large bandwidth, a low optical loss, and a small power consumption. A careful trade-off among these parameters usually has to be made when designing such a device. Here, we propose and demonstrate an electro-optic ring modulator on the thin-film lithium niobate platform without compromising between any performances. The device exhibits a low on-chip loss of about 0.15 dB with a high intrinsic quality-factor (Q-factor) of 7.7 × 10 5 . Since a pure coupling modulation is employed, the photon lifetime is no longer a limiting factor for the modulation speed. A large electro-optic bandwidth is obtained without any roll-off up to 67 GHz. The device, with a footprint of 3.4 m m × 0.7 m m , also exhibits a low half-wave voltage of 1.75 V, corresponding to a half-wave voltage length product of 0.35 V ⋅ c m considering the 2-mm-long modulation section. Driverless data transmission up to 240 Gb/s is also demonstrated with a peak-to-peak driving voltage of 0.75 V.

Induced-photorefractive attack against Quantum Key Distribution

“…As we know. the LNOI-based high-speed modulators not only have a higher modulation bandwidth [11,12] but also do not have the modulation-dependent loss [13,14] thanks to the Pockels effect [15]. It matches the requirements of QKD very well from both the modulation and security.…”

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

“…Although it has been proved theoretically that this configuration can support ultrahigh modulation bandwidth even with a high Q-factor ring resonator, only recently has such a device been realized experimentally on LNOI for the first time [Figure 1(j)]. 33 Using an MZI to tune the coupling coefficient to the ring, the photon lifetime is decoupled from the modulation speed of the device. This leads to fold improvements on the modulation efficiency of an LNOI EO modulator, as well as the bandwidth extension to THz range.…”

“…Another feasible improvement for the microcavity modulator is using the coupling-modulation. Although it has been proved theoretically that this configuration can support ultrahigh modulation bandwidth even with a high Q -factor ring resonator, only recently has such a device been realized experimentally on LNOI for the first time [Figure (j)] . Using an MZI to tune the coupling coefficient to the ring, the photon lifetime is decoupled from the modulation speed of the device.…”

High-speed electro-optic modulation in topological interface states of a one-dimensional lattice

“…High-performance electro-optic modulators have been demonstrated using the Pockels effect on the thin lm LN integrated platform [4][5][6] and are at the heart of ultralarge-capacity optical communication, terahertz wireless communication, microwave signal processing, sensing, and quantum technology 7 . The Mach-Zehnder interferometer (MZI) or ring-assisted MZI modulators on thinlm LN have the advantages of a large bandwidth and low driving voltage 1,4,8,9 . However, they require long phase shifters with lengths of 3 ~ 20 mm, resulting in a large device footprint.…”