Extending imaging depth of multiphoton microscopy

Abstract

Two-photon excitation fluorescence microscopy has capability of deep tissue imaging with biological samples. However, because of the inhomogeneity of the refractive index in biological samples, the wavefront of the excitation light is often distorted. Due to the distortion of the wavefront, the point spread function at the focal point becomes broadened resulting in degraded resolution and lower signal. With an adaptive optics system, which consists of a wavefront camera and deformable mirror, the wavefront distortion can be measured and corrected. By correcting the distorted wavefront with adaptive optics, resolution and signal level can be preserved at greater imaging depth.