Left Side. (A) Multiphoton relative luminescence signal generated by the QD, GNR, and UCNP solution as obtained under fs laser excitation at 800, 830 and 980 nm, respectively. Pump intensity was 1 MW/cm2; (B) Multiphoton relative luminescence signal generated by the QD, GNR, and UCNP solution as obtained under cw laser excitation at 800, 830 and 980 nm, respectively. Pump intensity was 1 MW/cm2. Right Side: Photos corresponding to the naked eye observations of the fluorescent samples. The pump intensity was kept the same in both cases (CW and 100 fs excitation) ([53], reproduced by permission of The Optical Society of America).