  We theoretically study chirped four-wave mixing for VUV pulse generation in
hollow-core photonic crystal fibers. We predict the generation of sub-10-fs VUV
pulses with energy of up to hundreds of microjoule by broad-band chirped idler
pulses at 830 nm and MW pump pulses with narrow-band at 277 nm. MW pump could
be desirable to reduce the complexity of the laser system or use a high
repetition rate-laser system. The energy conversion efficiency from pump pulse
to VUV pulse reaches to 30%. This generation can be realized in kagome-lattice
hollow-core PCF filled with noble gas of high pressure with core-diameter less
than 40 micrometers which would enable technically simple or highly efficient
coupling to fundamental mode of the fiber.
