Ultra-coherent meta-emitter tailors arbitrary thermal wavefront
摘要
Conventional coherent light-field manipulation techniques inherently conflict with the spatiotemporal incoherence of thermal radiation sources. While recent advances in thermophotonics have facilitated directional thermal emission, arbitrary thermal wavefront control—a cornerstone for advanced functionalities like focusing and holography—remains an unaddressed challenge. Here, we report a generalized recipe of designing meta-emitters with lossy and lossless outer boundaries, that enables thermal emission with arbitrarily tailored wavefront. Lossy and lossless surfaces on two sides of the meta-emitter are synergistically coupled by a single-mode waveguide, transforming incoherent thermal photons to coherent surface waves for wavefront shaping functionalities. Designer surface mode of meta-emitter permits the independent optimization of photon lifetime and propagation length, thus enabling scalable spatial coherence engineering. For the proof of concept, we experimentally demonstrate near-diffraction-limited self-focusing emission, quasi-two-dimensional (quasi-2D) high-quality thermal holography without speckle noise and spatial-multiplexed holography. Coupling optimization further suggests that spatial coherence exceeding 1000λ0 are achievable. Our proposed meta-emitter establishes a paradigm-shifting framework to integrate stochastic thermodynamic emission with precision photonic engineering, opening avenues for information-rich thermal radiation technologies.