Dual-wavelength high-power narrow-linewidth operation in diode lasers via beam-splitting external cavity

This study was focused on developing a method for achieving a high-power, narrow-linewidth, dual-wavelength laser output from a single laser diode array (LDA) by employing a right-angle prism and a dual-volume Bragg grating (VBG) based on beam-splitting external cavity feedback technology. The temperature drift properties of the VBGs with identical diffraction central wavelengths enabled dual-wavelength emissions at 779.944 and 780.360 nm with spectral linewidths of 0.082 and 0.076 nm, respectively. At an operating current of 60 A, the output power of the system was 48.5 W. Furthermore, by selecting VBGs with diffraction central wavelengths spaced at significant intervals, we achieved dual-wavelength laser emission with a specific spectral separation of 0.676 nm between their central wavelengths while maintaining spectral linewidths below 0.085 nm. This methodology establishes a compact structure for generating high-power, narrow-linewidth, and tunable dual-wavelength emissions from a single LDA source. Additionally, it enables the precise tuning of the spacing between the two central wavelengths to meet application requirements across various scenarios.