Suzuki Takamasa, Kaneko Yuzuki, Choi Samuel, Sasaki Osami
Opt Lett. 2022 Apr 1;47(7):1871-1874. doi: 10.1364/OL.454021.
In this study, a novel, to the best of our knowledge, external-cavity laser diode (ECLD) without a diffraction grating is proposed and demonstrated. In the proposed configuration, an acousto-optic deflector (AOD) acts not only as a deflector but also as a diffraction grating. Thus, the AOD functions as a wavelength-selective device, which helps improve the overall performance of the ECLD. In fact, the proposed configuration realizes a wide range of wavelength scanning with a simple configuration, highly efficient optical feedback, and a steady optical resonator with a constant cavity length. We confirm that the wavelengths scanned with the proposed ECLD agree well with theoretical calculations. The scanning range and maximum frequency response reached approximately 60 nm and 50 kHz, respectively. Moreover, reproducible measurements of the three-dimensional thickness distribution of a thin glass plate indicates that the proposed ECLD can be used for optical coherence tomography imaging systems.
在本研究中，据我们所知，提出并展示了一种新型的无衍射光栅外腔激光二极管（ECLD）。在所提出的结构中，声光偏转器（AOD）不仅作为一个偏转器，还作为一个衍射光栅。因此，AOD起到波长选择器件的作用，这有助于提高ECLD的整体性能。实际上，所提出的结构通过简单的配置、高效的光反馈以及具有恒定腔长的稳定光学谐振器实现了宽范围的波长扫描。我们证实，用所提出的ECLD扫描的波长与理论计算结果吻合良好。扫描范围和最大频率响应分别达到约60 nm和50 kHz。此外，对薄玻璃板三维厚度分布的可重复测量表明，所提出的ECLD可用于光学相干断层扫描成像系统。
