Quantum gases in lattice potentials have been a powerful platform to simulate phenomena from solid-state physics, such as the Mott insulator transition¹. In contrast to ultracold atoms, photon-based platforms, such as photonic crystals, coupled waveguides or lasers, usually do not operate in thermal equilibrium^2,3,4,5. Advances towards photonic simulators of solid-state equilibrium effects include polariton lattice experiments^6,7,8,9,10, and the demonstration of a photon condensate^11,12. Here, we demonstrate a technique to create variable micropotentials for light using thermo-optic imprinting of a dye–polymer solution within an ultrahigh-finesse microcavity. We study the properties of single- and double-well potentials, and find the quality of structuring sufficient for thermalization and Bose–Einstein condensation of light. The investigation of effective photon–photon interactions along with the observed tunnel coupling between sites makes the system a promising candidate to directly populate entangled photonic many-body states. The demonstrated scalability suggests that thermo-optic imprinting provides a new approach for variable microstructuring in photonics.

晶格势中的量子气体已成为模拟固态物理现象（例如Mott绝缘子跃迁^1）的强大平台。与超冷原子相反，基于光子的平台，例如光子晶体，耦合波导或激光器，通常不会在热平衡状态下运行^2,3,4,5。固态平衡效应的光子模拟器方面的进展包括极化子晶格实验^6,7,8,9,10以及光子冷凝物^11,12的演示。在这里，我们演示了一种通过在超高精细微腔内使用染料-聚合物溶液的热光压印来为光创建可变微电势的技术。我们研究了单井和双井势的性质，并发现结构化的质量足以实现光的热化和Bose-Einstein凝聚。对有效的光子-光子相互作用以及站点之间观察到的隧道耦合的研究使该系统成为直接填充纠缠光子多体态的有前途的候选者。证明的可扩展性表明，热光压印为光子学中的可变微结构提供了一种新方法。