The 1.5 μm laser is located both in the near-infrared atmospheric window and in the eye-safe wavelength band, so there is a wide demand for 1.5 μm lasers in fields such as optical communication, laser ranging, and lidar. Currently, optical parametric oscillators (OPOs) based on the principle of nonlinear frequency conversion, represent a prominent approach for generating 1.5 μm lasers. KTiOAsO₄ (KTA) is an ideal material for generating 1.5 μm laser output via OPO technology due to its high nonlinear coefficient, broad transmission range, and high damage threshold. However, research in this field has primarily focused on extracavity OPOs operating below 100 Hz and intracavity OPOs operating above kHz. While low repetition frequency extracavity KTA-OPOs have successfully achieved high power 1.5 μm laser output, the output power levels of high repetition frequency intracavity KTA-OPOs are generally lower due to limitations of intracavity power density. In response to the current research status and the demand for high repetition frequency and high power 1.5 μm lasers in application fields, the 10 kHz 1.5 μm laser output power is enhanced by utilizing extracavity KTA-OPO.To obtain a pump beam with a repetition rate of 10 kHz and good beam quality, a master oscillator power amplifier (MOPA) system was constructed using LD end-pumped Nd:YVO₄ crystals. The 1064 nm oscillator utilizes a BBO crystal for electro-optic Q-switching to achieve a 10 kHz laser, and three-stage amplification is carried out afterwards. In the amplifier stages, to minimize the impact of thermal effects, the first two stages employ single-end pumping, while the third stage uses dual-end pumping. Lenses are placed between each stage to ensure good mode matching between the pump and oscillation spots. During the OPO stage, a plane-plane cavity OPO is built using KTA as the nonlinear crystal to achieve type II non-critical phase matching for the generation of 1.5 μm parametric light. The optical-to-optical conversion efficiency is enhanced by optimizing the pump spot size and the oscillator cavity length (Fig.1).Through electro-optic Q-switching technology, the oscillator achieves a 1064 nm laser output of 1.02 W, with a repetition rate of 10 kHz and a pulse width of 7.1 ns. The beam quality factors are M²_x=1.18 and M²_y=1.20 (Fig.2). Using 878 nm LDs as the pump sources, the oscillator power was successfully increased to 6.26 W, 12.40 W, and 20.13 W. The corresponding beam qualities are as follows: for the first stage, M²_x=1.20, M²_y=1.26; for the second stage, M²_x=1.32, M²_y=1.26; for the third stage, M²_x=1.42, M²_y=1.49 (Fig.4). With a cavity length of 40 mm and a pump spot diameter of 430 μm, the KTA-OPO generates a laser with a central wavelength of 1535.8 nm and a maximum output power of 6.26 W (Fig.5). The corresponding optical-to-optical conversion efficiency is 33%, with a pulse width of 7.2 ns and a linewidth of 0.26 nm. The beam quality factors are M²_x=2.75 and M²_y=3.81 (Fig.6).A high-power 1.5 μm laser with a repetition frequency of 10 kHz has been successfully obtained using an extracavity KTA-OPO structure. To achieve high beam quality pump beam, a MOPA was constructed using LD end-pumped Nd:YVO₄ crystals. By combining single-end pumping and double-end pumping in a three-stage amplification, a 1064 nm pump light with a beam quality factor better than 1.5 and a pulse repetition rate of 10 kHz was obtained, with an average power of 20.13 W. In the aspect of the KTA-OPO, the effects of cavity length and pump spot diameter on the pump threshold and conversion efficiency were comparatively studied. The pump spot parameters and resonator parameters were optimized to improve the conversion efficiency of the KTA-OPO, 1.5 μm pulsed laser with an average power of 6.26 W and a pulse width of less than 10 ns, corresponding to an optical-to-optical conversion efficiency of up to 33%. Adoption of extracavity KTA-OPO structure effectively improves the high-frequency 1.5 μm laser output power. Subsequent improvements should focus on enhancing the 1064 nm pump laser power while maintaining good beam quality. Additionally, adopting a ring cavity structure could further optimize the beam quality of the KTA-OPO. Moreover, single-frequency seed injection could be employed to narrow the output linewidth, thereby meeting practical application requirements.