Fig. 1: Photonic computing accelerator on thin-film lithium niobate.

a Concept of photonic computing accelerators. Data stored in the electronic system (e.g. a computer) are sent to the photonic accelerator at high rates and are converted into the optical domain. Parallel computations are then performed by the accelerator and results are returned to the electronic system. b Illustration of the photonic computing working principle. Continuous-wave light passes through two cascaded amplitude modulators (AMs) which sequentially encode elements of \(\vec{x}\) and \(\vec{a}\) onto the amplitude of light, effectively performing element-wise multiplication of the two vectors. The components contributing to \(\vec{x}\cdot \vec{a}\) are read out by optical-to-electronic conversion using a low-noise and high-speed detector, and electronic summation of these components finally yields \(\vec{x}\cdot \vec{a}\). c The vision for a fully integrated computing core based on TFLN photonics, consisting of laser, detectors, and TFLN modulators for high-speed and energy-efficient EO conversion and computation. An input vector is first encoded in the time domain of the optical field through an amplitude modulator and then fanned-out into \(N\) spatial channels (\(N=16\) in this figure) to leverage massive spatial parallelism. In each channel, another amplitude modulator is used to multiply weights with the input vector. Finally, detectors convert the multiplication results back into electronic signals.