The nanosecond pulse laser was generally used in the fabrication

of a variety of nanocrystals. With much longer pulse duration

and much lower power density, microsecond-pulse-laser ablation

may correspond to dramatically different physical and chemical

processes compared to short-pulse-duration-laser ablation. In this

chapter, we present our recent experimental and theoretical

studies on the preparation of nanomaterials by microsecond-pulse-

laser ablation in liquid media. Particularly, we have synthesized

ultrafine nanodiamonds (3-6 nm)1−3 and face-centered-cubic (fcc) Si4 nanocrystals that have never been reported in published

articles on laser ablation with nanosecond pulse width. Besides, Si

and SiC nanospheres have been prepared by laser-induced phase

separation.5 One-step synthesis of fluorescent carbon nanoparticles

(CNPs),6 mixed-phase TiO2 nanospheres, 7 and noble-metal/oxide

nanocomposites8 have also been achieved by laser ablation with

a microsecond laser. Moreover, our work on controllable synthesis

of two different kinds of Si-C nanostructures by laser ablation in

gaseous carbon source9 is also included in this chapter.