Electrical engineering

Physics

Bandwidth (computing)

Lithium niobate

Phase noise

Insertion loss

Phase modulation

Optics

Engineering

Voltage

Interferometry

Materials science

Optical modulator

Silicon nitride

Silicon

Extinction ratio

Optoelectronics

Broadband

Wavelength

Telecommunications

APL Photonics

This paper reports a hybrid silicon nitride–lithium niobate electro-optic Mach–Zehnder-interferometer modulator that demonstrates overall improvements in terms of half-wave voltage, optical insertion loss, extinction ratio, and operational bandwidth. The fabricated device exhibits a DC half-wave voltage of ∼1.3 V, a static extinction ratio of ∼27 dB, an on-chip optical loss of ∼1.53 dB, and a 3 dB electro-optic bandwidth of 29 GHz. In addition, this device operates beyond the 3 dB bandwidth, where a half-wave voltage of 3 V is extracted at 40 GHz when the device is biased at quadrature. The modulator is realized by strip-loading thin-film lithium niobate with low-pressure chemical vapor deposited silicon nitride; this enables reduced on-chip losses and allows for a lengthened 2.4 cm long interaction region that is specifically engineered for broadband performance.

High-efficiency lithium niobate modulator for K band operation