Lee Gi Hyen, Ahn Soyeon, Kim Min Su, Lee Sang Won, Kim Ji Su, Choi Byeong Kwon, Pagidi Srinivas, Jeon Min Yong
Department of Physics, College of Natural Sciences, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea.
Institute of Quantum Systems (IQS), Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea.
Sensors (Basel). 2022 Nov 16;22(22):8867. doi: 10.3390/s22228867.
Broadband wavelength-swept lasers (WSLs) are widely used as light sources in biophotonics and optical fiber sensors. Herein, we present a polygonal mirror scanning wavelength filter (PMSWF)-based broadband WSL using two semiconductor optical amplifiers (SOAs) with different center wavelengths as the gain medium. The 10-dB bandwidth of the wavelength scanning range with 3.6 kHz scanning frequency was approximately 223 nm, from 1129 nm to 1352 nm. When the scanning frequency of the WSL was increased, the intensity and bandwidth decreased. The main reason for this is that the laser oscillation time becomes insufficient as the scanning frequency increases. We analyzed the intensity and bandwidth decrease according to the increase in the scanning frequency in the WSL through the concept of saturation limit frequency. In addition, optical alignment is important for realizing broadband WSLs. The optimal condition can be determined by analyzing the beam alignment according to the position of the diffraction grating and the lenses in the PMSWF. This broadband WSL is specially expected to be used as a light source in broadband distributed dynamic FBG fiber-optic sensors.
宽带扫频激光器（WSL）在生物光子学和光纤传感器中被广泛用作光源。在此，我们展示了一种基于多边形镜扫描波长滤波器（PMSWF）的宽带WSL，它使用两个中心波长不同的半导体光放大器（SOA）作为增益介质。扫描频率为3.6 kHz时，波长扫描范围的10 dB带宽约为223 nm，从1129 nm至1352 nm。当WSL的扫描频率增加时，强度和带宽会降低。主要原因是随着扫描频率增加，激光振荡时间变得不足。我们通过饱和极限频率的概念分析了WSL中扫描频率增加时强度和带宽的降低情况。此外，光学对准对于实现宽带WSL很重要。可以通过根据PMSWF中衍射光栅和透镜的位置分析光束对准来确定最佳条件。这种宽带WSL特别有望用作宽带分布式动态FBG光纤传感器的光源。
