An imaging system including a multi-mode fiber and a gradient index (GRIN) lens. The invention also relates to a system including a multi-mode fiber, such as a double-clad photonic crystal fiber, for transmitting an excitation signal to a sample for the purpose of imaging, and a scanning mechanism, which preferably includes a microelectromechanical system (MEMS) mirror, for reflecting the excitation signal in varying directions in order to scan the sample.