University of California Irvine, Beckman Laser Institute and Medical Clinic, Laser Microbeam and Med, United States.
University of Notre Dame, Department of Electrical Engineering, Notre Dame, Indiana, United States.
J Biomed Opt. 2017 Oct;22(10):1-8. doi: 10.1117/1.JBO.22.10.105001.
Frequency-domain photon migration (FDPM) uses modulated laser light to measure the bulk optical properties of turbid media and is increasingly applied for noninvasive functional medical imaging in the near-infrared. Although semiconductor edge-emitting laser diodes have been traditionally used as miniature light sources for this application, we show that vertical-cavity surface-emitting lasers (VCSELs) exhibit output power and modulation performance characteristics suitable for FDPM measurements of tissue optical properties at modulation frequencies exceeding 1 GHz. We also show that an array of multiple VCSEL devices can be coherently modulated at frequencies suitable for FDPM and can improve optical power. In addition, their small size and simple packaging make them an attractive choice as components in wearable sensors and clinical FDPM-based optical spectroscopy systems. We demonstrate the benefits of VCSEL technology by fabricating and testing a unique, compact VCSEL-based optical probe with an integrated avalanche photodiode. We demonstrate sensitivity of the VCSEL-based probe to subcutaneous tissue hemodynamics that was induced during an arterial cuff occlusion of the upper arm in a human subject.
频域光迁移（FDPM）使用调制激光来测量混浊介质的体光学性质，并且越来越多地应用于近红外光的无创功能医学成像。虽然半导体边缘发射激光二极管（edge-emitting laser diode）传统上被用作这种应用的微型光源，但我们表明，垂直腔面发射激光器（VCSEL）在调制频率超过 1GHz 时表现出适合 FDPM 测量组织光学性质的输出功率和调制性能特征。我们还表明，多个 VCSEL 器件的阵列可以在适合 FDPM 的频率下进行相干调制，并可以提高光功率。此外，它们的体积小且封装简单，使其成为可穿戴传感器和临床基于 FDPM 的光谱学系统中组件的有吸引力的选择。我们通过制造和测试具有集成雪崩光电二极管的独特紧凑型 VCSEL 基光学探头来展示 VCSEL 技术的优势。我们证明了 VCSEL 基探头对人体上肢动脉袖带阻塞期间皮下组织血液动力学的敏感性。
