中国激光, 2014, 41 (11): 1102002, 网络出版: 2014-10-08
单偏振半导体光放大器扫频光相干成像系统
Optical Coherence Imaging System Based on a Polarization-Dependent Semiconductor Optical Amplifier-Enabled Swept Laser
相干光学 傅里叶域锁模结构光源 光相干层析 光相干显微镜 半导体光放大器 coherence optics Fourier domain mode locked laser optical coherence tomography optical coherence microscopy semiconductor optical amplifier
摘要
搭建完成了基于单偏振半导体光放大器扫频光源的光相干成像系统,此系统可以实现高速光相干层析成像与光相干显微成像。系统中的扫频光源使用偏振相关的半导体光放大器作为放大单元,该光放大器有着增益谱宽大、输出功率高的优点,使得光源仅使用一个放大器即可获得合适的增益谱宽与输出功率,并可采用傅里叶域锁模技术大幅提高其扫频速率。采用傅里叶域锁模技术时,扫频光源输出功率达到32 mW左右,有效扫描频率为45 kHz,输出光谱的中心波长为1326 nm,光谱宽度为115 nm。利用系统进行高速光相干层析成像时,横向分辨率为9 μm,纵向分辨率为12.9 μm左右,灵敏度为105 dB。利用系统进行光相干显微成像时,可以清楚地看到洋葱内表皮细胞的结构。
Abstract
As noninvasive biomedical imaging techniques, optical coherence tomography (OCT) and optical coherence microscopy have good application prospects in future. A swept-source imaging system based on a polarization-dependent semiconductor optical amplifier (SOA) enabled Fourier domain mode locked laser (FDML) is demonstrated, which can be used for the two imaging techniques mentioned above. The FDML with a polarization-dependent SOA generates ~32 mW output power at 45 kHz sweep rates, with a tuning range of 115 nm centered at 1326 nm. Because of the broad bandwidth and high saturation power of the polarization-dependent SOA, the laser has the advantage of simple structure. It uses only one SOA for operating with enough bandwidth and output power. Using the SOA-enabled FDML laser, an OCT system with axial resolution of ~12.9 μm, transverse spot size of 9 μm and sensitivity of 105 dB is achieved. The structure of the epidermal cells of onion can be observed by this imaging system.
尚怀嬴, 霍力, 吴远鹏, 娄采云. 单偏振半导体光放大器扫频光相干成像系统[J]. 中国激光, 2014, 41(11): 1102002. Shang Huaiying, Huo Li, Wu Yuanpeng, Lou Caiyun. Optical Coherence Imaging System Based on a Polarization-Dependent Semiconductor Optical Amplifier-Enabled Swept Laser[J]. Chinese Journal of Lasers, 2014, 41(11): 1102002.