twophoton

Physics

Scientists decipher two-photon vision

optical system. The IR and VIS beams were generated by a femtosecond laser (pulse width τ=200 fs, repetition rate F = 76 MHz). BS, beam splitter. CAM, camera; GS, galvanometer scanner; IF, 940 nm bandpass filter; IL, illuminator. L, lens. LED, white light emitting diode. M, mirror. NDF, neutral density filter. NDV, neutral density gradient filter; OBJ, objective. PM, power…