Ultralow-threshold Raman laser using a spherical dielectric microcavity
Ultralow-threshold Raman laser using a spherical dielectric microcavity
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DOI：
10.1038/415621a
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发表时间：
2002-02-07
期刊：
影响因子：
64.8
通讯作者：
Vahala, KJ
中科院分区：
文献类型：
--
作者：
Spillane, SM;Kippenberg, TJ;Vahala, KJ
将光能限制并存储在小体积内的能力在从腔量子电动力学到光子学等诸多领域都具有重要意义。在所有的腔几何结构中，微米尺寸的介电球形谐振器在小体积内长时间存储能量的能力方面是最佳的（1）。在球体中，光在表面附近环绕，较长的限制时间（高Q值）有效地将较大的相互作用距离压缩在一个微小的体积内。这一特性使得此类谐振器特别适合用于研究光与物质的非线性耦合。早期的研究工作（2,3）通过微液滴中的拉曼激发认识到了这些特性——但微液滴尚未在实际应用中得到使用。在此我们展示了一种微米级的非线性拉曼源，它具有高效的泵浦 - 信号转换效率（高于35%），并且泵浦阈值比之前所展示的低近1000倍。这为众多通常难以获取的波长波段提供了一种实现紧凑、超低阈值光源的途径。同样重要的是，该系统可以为研究非线性光学效应和光的量子特性提供一个紧凑且简单的构建模块。
The ability to confine and store optical energy in small volumes has implications in fields ranging from cavity quantum electrodynamics to photonics. Of all cavity geometries, micrometresized dielectric spherical resonators are the best in terms of their ability to store energy for long periods of time within small volumes(1). In the sphere, light orbits near the surface, where long confinement times (high Q) effectively wrap a large interaction distance into a tiny volume. This characteristic makes such resonators uniquely suited for studies of nonlinear coupling of light with matter. Early work(2,3) recognized these attributes through Raman excitation in microdroplets-but microdroplets have not been used in practical applications. Here we demonstrate a micrometre-scale, nonlinear Raman source that has a highly efficient pump-signal conversion (higher than 35%) and pump thresholds nearly 1,000 times lower than shown before. This represents a route to compact, ultralow-threshold sources for numerous wavelength bands that are usually difficult to access. Equally important, this system can provide a compact and simple building block for studying nonlinear optical effects and the quantum aspects of light.