Ren Dingding, Dong Chao, Høvik Jens, Khan Md Istiak, Aksnes Astrid, Fimland Bjørn-Ove, Burghoff David
Department of Electrical Engineering, University of Notre Dame, Notre Dame, USA.
Department of Electronic Systems, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
Nanophotonics. 2024 Jan 8;13(10):1815-1822. doi: 10.1515/nanoph-2023-0698. eCollection 2024 Apr.
The longwave infrared (LWIR) range, which spans from 6 µm to 14 µm, is appealing for sensing due to strong molecular fingerprints in this range. However, the limited availability of low-loss materials that can provide higher-index waveguiding and lower-index cladding in the LWIR range presents challenges for integrated photonics. In this work, we introduce a low-loss germanium-on-zinc selenide (GOZ) platform that could serve as a versatile platform for nanophotonics in the LWIR. By bonding high-quality thin-film germanium (Ge) to a zinc selenide (ZnSe) substrate, we demonstrate transparency from 2 µm to 14 µm and optical losses of just 1 cm at 7.8 µm. Our results demonstrate that hybrid photonic platforms could be invaluable for overcoming the losses of epitaxially grown materials and could enable a wide range of future quantum and nonlinear photonics.
长波红外（LWIR）范围为6微米至14微米，由于该范围内存在强烈的分子指纹，因此在传感方面具有吸引力。然而，在LWIR范围内，能够提供更高折射率波导和更低折射率包层的低损耗材料供应有限，这给集成光子学带来了挑战。在这项工作中，我们引入了一种低损耗的硒化锌上锗（GOZ）平台，该平台可作为LWIR中纳米光子学的通用平台。通过将高质量的薄膜锗（Ge）与硒化锌（ZnSe）衬底键合，我们展示了从2微米到14微米的透明度，以及在7.8微米处仅为1厘米的光学损耗。我们的结果表明，混合光子平台对于克服外延生长材料的损耗可能具有极高的价值，并可能推动未来广泛的量子和非线性光子学发展。
