Coherent combining of independently generated supercontinuum sources

Coherent beam combining (CBC) has matured as a proven method for scaling laser brightness beyond the limits achievable by a single laser alone, though its applications have been limited to narrowband sources. Utilizing all-normal dispersion photonic crystal fibers (ANDi PCFs) for coherent supercontinuum generation has the potential to increase the brightness achievable for broadband sources in a CBC architecture. A two-channel system is experimentally demonstrated, producing over 230 nm of bandwidth with ∼300 mW of average power. The spectra are generated via independent ANDi PCFs with a common amplifier and then recombined using a spectrally resolved Mach-Zehnder interferometer, where an average coherence of 0.71 is measured across the spectrum. This two-channel proof-of-concept experiment paves the way toward further brightness scaling of supercontinuum sources via a multi-channel CBC architecture with independent amplifiers.