Here, we develop a novel design approach that co-optimizes inverse-designed wavelength division multiplexers and distributed Bragg gratings to achieve ultra-low crosstalk without compromising insertion loss. While Fiberdyne offers some models as "standard," we will also produce customized DWDM modules. Customization can include the number and selection of DWDM channels. We experimentally demonstrate less than -40 dB crosstalk for wavelength channel spacing of. Corning's R&D scientists are constantly searching for new ways to improve wavelength division multiplexing (WDM) technology. Wavelength division multiplexing is a method of modulating multiple signals at different wavelengths (channels) to transmit them on a single waveguide or fiber. To begin with, we assume that we have the element.