We present a 1.5-\mum continuous-wave (CW) single-frequency intracavity singly resonant optical parametric oscillator (SRO) based on periodically poled lithium niobate (PPLN). The SRO is placed inside the ring cavity of a single-frequency 1.06-\mum Nd:YVO4 laser pumped by a laser diode. The device delivers a maximum single-frequency output power of 310 mW at a resonant signal wavelength of 1.57 \mum. The signal wave could be tuned from 1.57 to 1.59 \mum by temperature tuning of PPLN crystal over the range of 130-170 oC.