scattering (SRS), are common and propitious ways to obtain multi-wavelengths. During the past decades, various kinds of OPO operations have been investigated and it is shown that OPO technology can generate widely tunable coherent radiation [6][7][8]. As another efficient frequency conversion method, stimulated Raman scattering (SRS) has been already demonstrated and widely used for creating intense coherent radiation over the visible and near infrared [9][10][11]. In recent years, to pursue more convenient multiwavelength laser sources, the investigation by combining χ (2) and χ (3) for nonlinear frequency conversions in a same crystal has become a research hotspot. The related investigations show that the combination of χ (2) and χ (3) nonlinear frequency conversions can obtain multi-wavelengths efficiently [12][13][14][15][16][17]. As an excellent nonlinear crystal, KTi-OPO 4 (KTP) has the merits of good mechanical and optical properties, high damage threshold and possibility for noncritical phase matching. Moreover, the anisotropic Raman spectra, Raman gain coefficient and strongest Raman scattering of KTP about 2 cm/GW and 270 cm −1 have been reported [18,19]. Consequently, it has attracted a lot of attention in research field of frequency doubling, . However, up to now, the combination of OPO and SRS to obtain multi-wavelengths by using KTP as simultaneous multi-functional medium has rarely been reported. Recently, although simultaneous OPO and SRS processes from a single KTP pumped by a passively Q-switched laser were realized [24], there was no related theoretical analysis.As a derivative of Nd:Gd 3 Ga 5 O 12 (Nd:GGG) crystal, the isotropy disordered crystal Nd:LGGG has been considered as an excellent medium for the diode-pumped solid-state laser due to its good mechanical, thermal and optical properties. What is more, due to its inhomogeneous broadening absorption and emission bands [25], Nd:LGGG crystal may Abstract Coexistent intracavity KTiOPO 4 optical parametric oscillator (OPO) and stimulated Raman scattering (SRS) processes pumped by an acousto-optical Q-switched Nd:Lu x Gd 3−x Ga 5 O 12 (Nd:LGGG) laser were presented for the first time. The Stokes radiations at 1093.2/1125.8 nm and a signal wave of 1570 nm were generated. At an incident pump power of 9.25 W and pulse repetition rate of 3 kHz, the maximum output powers of 375 mW at 1570 nm and 98 mW at 1093.2/1125.8 nm were obtained for the signal wave and Stokes radiations, respectively, corresponding to a total conversion efficiency of 5.1 %. A set of coupled rate equations for coexistent OPO and SRS processes was developed, and the numerical solutions agreed with the experiment results.