Rotational multiphoton endoscopy with a 1 μm fiber laser system

We present multiphoton microendoscopy with a rotational probe and a 1 μ m fiber-based femtosecond laser. The rotational probe is based on a double-clad photonic crystal fiber, a gradient index lens, a microprism, and a rotational microelectronicmechanical system (MEMS) motor. The MEMS motor has a diameter of 2.2 mm and can provide 360° full-view rotation. The fiber laser provides ultrashort pulses with a central wavelength at 1.034 μ m and a repetition rate of 50 MHz. Second-harmonic-generation images of rat-tail tendon and fish scale are demonstrated with the rotational probe-based multiphoton system.