A multi-photon imaging system includes a laser module having a first channel for outputting a two-photon excitation laser pulse and a second channel for outputting a three-photon excitation laser pulse. The system further includes a first optical path for guiding the two-photon laser pulse from the first channel of the laser module and a second optical path for guiding the three-photon laser pulse from the second channel of the laser module. A microscope is also provided for simultaneously receiving the two-photon laser pulse from the first optical path and the three-photon laser pulse from the second optical path, and simultaneously, or with well controllable delays, delivering the two-photon laser pulse and the three-photon pulse to a target volume. The system further includes a photodetector configured to collect photons generated within the target volume in response to simultaneous excitation of the target volume by both the two-photon laser pulse and the three-photon laser pulse.