High sensitivity temporal focusing widefield multiphoton endoscope capable of deep imaging

A method for performing deep tissue imaging through improving the optical sectioning as well as the rejection of background signal comprising:

• providing a pulsed light source that provides pulsed light;
• positioning one or more dispersive elements to receive the pulsed light and apply selective dispersive properties to recombine the spectrally dispersed pulse at a certain position along the optical axis where with the recombined pulse a sequence of two photon (2p) wide field uniform illumination and 2p wide field structured illumination is generated at the focal plane;
• and
• receiving multiple 2p wide field uniform illumination and 2p wide field structured illumination images to produce respective 3D resolved images of a sample using an imaging element, wherein the group velocity dispersion (GVD) of the pulsed light is tuned to induce a quadratic spectral phase, which effectively shifts the focal plane and thereby allows scanning in the axial direction of the pulsed light.