Optical limiting of semiconductor nanoparticles for nanosecond laser pulses

摘要: Optical limiting of nanosecond laser pulses at 532 nm has been observed in CdxAg1−xS semiconductor nanoparticles within organic solution polymeric ionic aggregates. Both free-carrier absorption (FCA) and nonlinear scattering contribute to the optical performance. The response CdS nanoparticles, diameter range 2–9 nm, increases with increase particle size. It can be further increased by surface coating a thin layer Ag2S or forming ternary particle. FCA cross sections solutions were estimated between 10−19 10−18cm2, which are comparable those bulk semiconductors.