Two-photon endomicroscopy with microsphere-spliced double-cladding antiresonant fiber for resolution enhancement

Abstract

We demonstrate a miniature fiber-optic two two-photon endomicroscopy with microsphere-spliced double-cladding antiresonant fiber for resolution enhancement. An easy-to-operate process for fixing microsphere permanently in an antiresonant fiber core, by arc discharge, is proposed. The flexible fiber-optic probe is integrated with a parameter of 5.8 mm × 49.1 mm (outer diameter × rigid length); the field of view is 210 µm, the resolution is 1.3 µm, and the frame rate is 0.7 fps. The imaging ability is verified using ex-vivo mouse kidney, heart, stomach, tail tendon, and in-vivo brain neural imaging.

Lensed fiber-optic scanning two-photon endomicroscopic imaging

“…Subsequently, the fabrication of the lensed fiber for TPEM is achieved through sequential processes, including precise length cutting and arc discharge. More detailed information on the fabrication process of the lensed fiber can be found in our previous work [8].…”

“…In this work, we enhance the imaging resolution of the lensed fiber-optic scanning two-photon endomicroscopic imaging scheme [8]. By optimizing a lensed fiber designed for two-photon endomicroscopy (TPEM), we integrated it into a fiber-optic scanning TPEM platform, achieving a lateral resolution of 2.1 μm and a field of view (FOV) of 600 μm.…”

Modeling and analysis of reverse-fixed piezoelectric tube fiber scanner for two-photon endomicroscopy

“…Microelectromechanical systems (MEMS) scanner and piezoelectric actuated fiber scanner are common scanning methods for miniature two-photon microscopy with distal scanning structures. The structure of the piezoelectric tube (PZT) fiber scanner does not require optical path folding, making it more suitable for two-photon endomicroscopy application requirements potentially [6][7][8][9][10]. The PZT fiber scanner is one of the critical components of the fiber-scanning TPEM, and its performance affects the frame rate, scanning range, and integrated probe size directly.…”

Comparison between forward-fixed and reverse-fixed PZT fiber scanner for nonlinear endomicroscopy

“…For the early diagnosis of gastrointestinal/brain tumors, piezoelectric ceramic tube (PZT) fiber-optic scanning endomicroscopy has rapidly evolved, encompassing modalities such as endoscopic optical coherence tomography [1], confocal endomicroscopy [2,3], and nonlinear endomicroscopy [4,5]. Two-photon endomicroscopy (TPEM), founded upon the principle of two-photon fluorescence excitation [6], demonstrates distinct technological advantages, including deeper tissue penetration and label-free imaging, thus positioning it as a robust endomicroscopic technique for in-vivo imaging [7][8][9]. In comparison to the microelectromechanical scanning configuration, the PZT fiber scanning configuration adopts a straight cylindrical design, which enhances its compatibility for integration within miniature probe platforms.…”