Significance: Spectral-domain optical coherence tomography (SD-OCT) offers depth-resolved imaging of optical scattering contrast but is limited in sensitivity to optical absorption. Dual-modality imaging combined with the noncontact absorption contrast of photoacoustic remote sensing (PARS) microscopy can augment SD-OCT applications with specific molecular and functional contrasts in an all-optical, fiber-based platform. Aim: To develop a fiber-based multimodal PARS and SD-OCT imaging system, which efficiently uses a common 1050-nm light source for SD-OCT and PARS interrogation. Approach: PARS microscopy has predominantly utilized a 1310-nm interrogation light source to date. Hence, a recent dual-modality PARS and 1050-nm SD-OCT imaging system required three distinct wavelengths including a 532-nm PARS excitation, necessitating a free-space optical architecture with discrete subsystems. Here, we validate the first use of a 1050-nm interrogation wavelength for PARS. This enables the transition to fiber-based interferometry as is standard in modern SD-OCT systems, though infeasible with inclusion of an additional 1310-nm wavelength. PARS interrogation functionality is integrated using a broadband optical circulator. Results: Dual-modality imaging is demonstrated in carbon fiber phantoms and a mouse ear in vivo. SD-OCT provided a 4.5-μm lateral resolution, 8.8-μm axial resolution in air, and >101 dB of sensitivity, and PARS contributed 532-nm optical absorption contrast with a 47-dB SNR, and lateral and axial resolutions of 2.4 and 35 μm, respectively. Total interrogation power was reduced from 90% to 58% of the ANSI limit compared to a previous three-wavelength approach. Conclusions: Adapting PARS to use the 1050-nm SD-OCT light source for interrogation enabled implementation of a fiber-based dual-modality system configuration, with image quality maintained. This will facilitate development of potential applications demanding handheld, catheter-based, or endoscopic form factors.

中文翻译：

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基于光纤的光声遥感显微镜和具有双功能 1050 nm 询问源的光谱域光学相干断层扫描

意义：谱域光学相干断层扫描 (SD-OCT) 提供光学散射对比度的深度分辨成像，但对光学吸收的敏感性有限。双模态成像与光声遥感 (PARS) 显微镜的非接触式吸收对比相结合，可以在全光学、基于光纤的平台中通过特定的分子和功能对比来增强 SD-OCT 应用。目的：开发一种基于光纤的多模态 PARS 和 SD-OCT 成像系统，该系统有效地使用常见的 1050 nm 光源进行 SD-OCT 和 PARS 询问。方法：迄今为止，PARS 显微镜主要使用 1310 nm 询问光源。因此，最近的双模态 PARS 和 1050 nm SD-OCT 成像系统需要三种不同的波长，包括 532 nm PARS 激发、需要具有分立子系统的自由空间光学架构。在这里，我们验证了 PARS 首次使用 1050 nm 询问波长。这使得过渡到基于光纤的干涉测量成为现代 SD-OCT 系统的标准，尽管包含额外的 1310 nm 波长是不可行的。PARS 询问功能使用宽带光环行器进行集成。结果：双模态成像在体内碳纤维模型和小鼠耳朵中得到证实。SD-OCT 提供 4.5-μm 横向分辨率、8.8-μm 空气中轴向分辨率和 >101dB 的灵敏度，PARS 贡献了 532-nm 光吸收对比度和 47-dB SNR，横向和轴向分辨率为 2.4 和分别为 35 μm。与之前的三波长方法相比，总询问功率从 ANSI 限制的 90% 降低到 58%。结论：调整 PARS 以使用 1050 纳米 SD-OCT 光源进行询问能够实现基于光纤的双模态系统配置，同时保持图像质量。这将促进需要手持式、基于导管或内窥镜外形的潜在应用的开发。