We demonstrate a continuous-wave (CW) dual-wavelength Nd:YVO4 laser working at 1064 and 1066 nm simultaneously. The method of Nd:YVO4 crystal angle tuning is used to balance the ratio of the stimulated emission cross sections of the two wavelengths, leading to the realization of a simultaneous dual-wavelength operation from only one laser. The experimental results show that at a 2.85 W pump power, the maximum output powers at wavelengths of 1064 and 1066 nm are 0.55 and 0.54 W, respectively. The linear resonate cavity is as short as 10 mm, which gives the laser the advantages of a miniature configuration and low threshold. Such a dual-wavelength laser can be very attractive for the development of compact THz sources based on difference frequency generation.

We demonstrate wavelength-selectable visible emissions from a miniature crystalline laser that combines the stimulated Raman scattering (SRS) effect in an Nd:YVO4 crystal with intracavity frequency mixing in an angle-tuned beta barium borate (BBO) crystal. The presented laser is operating on demand at any one of three wavelengths in the green-yellow spectral region. Up to 600, 560, and 200 mW output powers at 559, 532, and 588 nm, respectively, are obtained from the continuous wave (CW) laser having a 18 mm long resonator and a 3.8 W laser diode end pumping. The pump threshold for each visible wavelength is less than 0.4 W.

The films of few-layer graphene are formed through laser exfoliation of a highly ordered pyrolytic graphite (HOPG), without a catalytic layer for the growth process. The femtosecond (fs) laser exfoliation process is investigated at different laser fluences and substrate temperature. For fs laser exfoliation of HOPG, the few-layer graphene is obtained at 473 K under an optimal laser fluence. The formation of few-layer graphene is explained by removal of intact graphite sheets occurred by an optimal laser fluence ablation. The new insights may facilitate the controllable synthesis of large area few-layer graphene.