We present a compact high-speed electro-optical modulator based on a thin-film lithium niobate platform for continuous-wave wireless-to-optical signal conversion, which collects terahertz signals between 82-380 GHz directly from free space via a large aperture on-chip antenna.

Terahertz technologies offer unique advantages for communication, sensing, and imaging, yet integrated platforms struggle to perform efficiently in this range. Thin-film lithium niobate, a nonlinear photonic platform, enables compact, broadband, and high-speed terahertz sources through efficient frequency conversion. In this talk, I present our progress on developing subterahertz continuous-wave sources on lithium niobate chips, aiming to bridge the gap between electronic and photonic systems for next-generation terahertz integration.

We present a wireless electro-optical modulator based on a thin-film lithium niobate operating at a millimeter-wave frequency range of 80-380 GHz, where the wireless signals are coupled to the on-chip transmission line directly from free space via a large aperture antenna.

We present an integrated photonic chip based on a thin-film lithium niobate platform that measures the autocorrelation function of coherent and non-coherent states of the terahertz electric fields with sub-cycle temporal resolution.

We present a photonic integration method combining flip-chip bonding and photonic wirebonding. This approach enables a 'mother' substrate to host 'child' chips from diverse platforms, fostering seamless integration for multi-functional photonic architectures.

This work presents a dual-tone source on thin film lithium niobate for generating a tunable carrier frequency at the terahertz domain. The system exhibits stable carrier generation above 100 GHz with sub-kHz linewidth and tunability of over 5 GHz.

We report a dual-tone source on thin-film lithium niobate for generating a tunable carrier frequency in the terahertz domain. The system achieves a stable carrier above 100 GHz, with sub-KHz linewidth and tunability over 5 GHz, offering a compact solution for integrated terahertz photonic systems.

We present a dual-functional integrated chip realized on a thin-film lithium niobate platform, serving as both terahertz emitter and detector, enabling broadband emission and detection from 0.1 to 2.5 THz.

The terahertz (THz) frequency region (0.1-10 THz) between microwaves and infrared, holds significant potential across various fields such as communication, sensing, and spectroscopy. Conventional THz systems for broadband emission and detection remain bulky and complex, making the development of a fully integrated, miniaturized THz system on a chip a significant challenge. Lithium niobate is an excellent material for THz emission and THz detection for its high second order nonlinearity and low optical losses in the near-infrared range [1]. Recently, thin-film lithium niobate (TFLN) platform has shown great potential for integrated THz systems [2-4]. Here, we develop a single device with dual functionalities based on the TFLN platform, capable of both THz emission and detection. Operating at the zero-dispersion wavelength (~1310 nm) for conventional single mode fiber, the system maintains short pulse duration without the requirement for complicated dispersion compensation methods, enabling broadband THz emission and detection from 0.1 to 2.5 THz.

We present emission up to 3 THz from a phase-matched terahertz-optical photonic circuit, featuring a co-planar metallic cavity traversed by an optical rib waveguide and a dipolar antenna for efficient out-coupling of terahertz waves.

We discuss recent progress in miniaturizing terahertz devices, facilitated by integrated photonic circuits. We show these provide ways to engineer dispersion, achieve field enhancement and realise complex functionalities on a single chip.

Terahertz science and technology is possibly now at an inflection point where integrated photonic circuits become increasingly viable sources and detectors of such high-frequency radiation. Generation in both second order [1] and third order [2,3,4] nonlinear waveguides and architectures thereof has exploited either optical rectification or microcomb generation with subsequent optical-to-terahertz conversion at a uni-travelling carrier photodiode. These initial demonstrations showcase a possible route towards miniaturized terahertz chips that are seamlessly integrated with photonics.