Raman-based technologies have enabled many ground-breaking scientific discoveries related to surface science, single-molecule chemistry and biology. For example, researchers have identified surface-bound molecules by their Raman vibrational modes and demonstrated polarization-dependent Raman gain. However, a surface-constrained Raman laser has yet to be demonstrated because of the challenges associated with achieving a sufficiently high photon population located at a surface to transition from spontaneous to stimulated Raman scattering. Here, advances in surface chemistry and in integrated photonics are combined to demonstrate lasing based on surface stimulated Raman scattering (SSRS). By creating an oriented, constrained Si–O–Si monolayer on the surface of integrated silica optical microresonators, the requisite conditions for SSRS are achieved with low threshold powers (200 μW). The expected polarization dependence of SSRS due to the orientation of the Si–O–Si bond is observed. Owing to the ordered monolayer, the Raman lasing efficiency is improved from ~5% to over 40%.

基于拉曼的技术已经实现了许多与表面科学，单分子化学和生物学有关的开创性科学发现。例如，研究人员通过拉曼振动模式识别了表面结合的分子，并证明了偏振相关的拉曼增益。然而，由于实现与位于表面的足够高的光子种群以从自发拉曼散射转变为受激拉曼散射有关的挑战，尚需证明表面受约束的拉曼激光。在这里，结合了表面化学和集成光子技术方面的进展，以证明基于表面受激拉曼散射（SSRS）的激光发射。通过在集成石英光学微谐振器的表面上形成定向的，受约束的Si–O–Si单层，使用低阈值功率（200μW）可以达到SSRS的必要条件。观察到由于Si–O–Si键的取向而引起的SSRS的偏振依赖性。由于有序的单层，拉曼激光的发射效率从5％提高到40％以上。