High-resolution endomicroscopy with a spectrally encoded miniature objective.

Fiber bundle endomicroscopy techniques have been used for numerous minimally invasive imaging applications. However, these techniques may provide limited spatial sampling due to the limited number of imaging cores inside the fiber bundle. Here, we present a custom-fabricated miniature objective that can be coupled to a fiber bundle and can overcome the fiber bundle's sampling threshold by utilizing the spectral encoding concept. The objective has an NA of 0.3 and an outer diameter of 2.4 mm, and can yield a maximum spatial resolution of 2 μm. The objective has been validated against a USAF resolution target and tissue samples, and as a result yielded images with higher resolution and more details after the spectral encoding concept was employed.