Application of the nonlinear optical properties of platinum nanoparticles for the mode locking of Nd:glass laser

We analyzed the saturated absorption of a platinum nanoparticle suspension using 1064-nm, 50-ps pulses at different intensities of laser radiation. The concurrence of reverse saturated absorption and saturated absorption at high intensities allowed for defining the saturated intensity for different suspensions of Pt nanoparticles (5×109 W cm−2). This suspension was used for the mode locking of laser radiation in a Nd:glass oscillator (λ=1054 nm). We achieved a stable generation of picosecond pulse trains with pulse duration of 5 ps using the mode locker based on the platinum nanoparticle suspension. The comparison of this nanoparticle-based mode locker with the conventional dye films showed the better stability of picosecond pulse generation and longer lifetime in the former case.