Ultraviolet-extended flat SC generation in seven-core photonic crystal fiber

An ultraviolet-extended broadband supercontinuum (SC) generation down to 350 nm wavelength is obtained by pumping a piece of uniform seven-core photonic crystal fiber with a tunable femtosecond laser at 800 nm, which extends the shortest wavelength in SC generation in seven-core PCF to date. High spectral flatness (10 dB) has been achieved in the entire visible window.