title: Efficient Generation of 200-230-nm Radiation in Beta Barium Borate by Noncollinear Sum-Frequency Mixing.
abstract: Tunable ultraviolet radiation in the 200-230-nm region has been generated with beta barium borate crystals by type I sum-frequency mixing of the second harmonic with the fundamental beam from a dye laser pumped by the second harmonic of the same Nd:YAG laser. A noncollinear phase-matching configuration has made it possible to realize conversion efficiency of 21% at 208.3 nm with input power densities as low as 28 MW/cm(2) for the fundamental and 2.4 MW/cm(2) for its second-harmonic radiation. The absorption characteristic of a standard DNA sample has been studied with the generated tunable ultraviolet source, revealing additional features compared with those obtained with a spectrophotometer.
authors.forename: G C
authors.initials: GC
authors.lastname: Bhar
authors.forename: P
authors.initials: P
authors.lastname: Kumbhakar
authors.forename: U
authors.initials: U
authors.lastname: Chatterjee
authors.forename: A M
authors.initials: AM
authors.lastname: Rudra
authors.forename: Y
authors.initials: Y
authors.lastname: Kuwano
authors.forename: H
authors.initials: H
authors.lastname: Kouta