Spectroscopy of liquids and microscopic specimens within liquid environment is important as much of the reactions concerning life on earth happen in the aqueous environment. However such study faces difficulty when we try to use photons from the parts (e.g. infrared or extreme ultraviolet) of the electromagnetic spectrum which get strongly absorbed within the aqueous environment. Although, sub-micron diameter cylindrical jets paved the way for development in this direction, these pose problem regarding refraction or scattering at the boundary reducing the signal quality . The recent advent of thin-flat jets can be proven to be useful circumventing all these problems. Attosecond spectroscopy of liquid water has been recently demonstrated with such a flat liquid jet . Here we report the development of a sub-micron thick flat jet with millimetre size extension. This flat jet is produced using a microfluidic gas-dynamic chip, similar to the one reported in Ref. . This chip has three micro-channels all converging at the bottom. The middle channel carries the liquid, whereas the outer channels carry the gas. Optimum gas and liquid flows produce such thin liquid jet. The system can be operated in air or in high vacuum condition. This presents the opportunity to do high resolution spectroscopy of liquid samples. The continuous flow of the liquid also ensures thermal damage free ultrafast spectroscopy especially using high repetition rate photon sources.
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