Coherent, narrow-band, tunable radiation in the extreme-ultraviolet spectral region was generated by a two-photon resonantly enhanced four-wave mixing process in krypton. Sum-generated radiation was produced near 942, 928, and 923 Å with power efficiencies as high as 10−5. Difference-generated radiation near 1312 Å was also detected.
© 1985 Optical Society of America
Keith D. Bonin and T. J. McIlrath, "Generation of tunable coherent radiation below 1000 Å by four-wave mixing in krypton," J. Opt. Soc. Am. B 2, 527-534 (1985)