The 981 nm 140 W Fiber Coupled Laser Diode is a high-brightness pump source engineered for the most demanding fiber laser and scientific applications. By utilizing integrated volume Bragg grating (VBG) technology, this module achieves a precise 981 ±1 nm center wavelength with an ultra-narrow spectral width, ensuring maximum absorption efficiency in Yb-doped gain media. Delivering a massive 140 W output through a high-precision 105 µm core fiber, the K981 series is built for absolute stability. It features integrated Feedback Isolation (30 dB) to protect the diode from back-reflections in high-power systems, and maintains a 45% electrical-to-optical efficiency. Designed for seamless industrial integration with an FC-Ferrule termination and optimized thermal management, this module provides the high-intensity, wavelength-locked performance required for next-generation kilowatt-class laser systems and for high-power mid-infrared lasers operating near 2800 nm.