Abstract: A method of emitting on a specific wavelength Fraunhofer line of peak seawater transmission and minimum solar radiation is disclosed. This method includes the steps of emitting at least on a specific wavelength of an infrared transition line from a neodymium gain element in an optical resonator; frequency tripling the infrared line from the resonator to a specific ultraviolet wavelength in a frequency multiplier; and Raman down shifting the specific ultraviolet wavelength a predetermined degree by a predetermined number of Stokes shifts in a predetermined medium in a Raman shifter to produce a high peak-power output at the specific wavelength Fraunhofer line.

Abstract: A chromium doped solid-state high peak-power laser transmitter emits at a 4861.342 or 4340.50 Angstrom Fraunhofer line, lines of peak blue-seawater transmission and minimum solar radiation. A pink ruby gain medium doped with approximately 0.05% chromium ion is temperature tuned to an R2 line at 6924.51 Angstrom wavelength and an R1 line is dispersively suppressed in a laser oscillator cavity also tuned to 6924.51 Angstrom. The oscillator is Q-switched and the amplified high peak-power 6924.51 Angstrom R2 line output is frequency doubled to 3462.26 Angstrom and hydrogen Raman down-shifted 8310 cm.sup.-1 to the second-Stokes at 4861.342 Angstrom to produce said high peak-power output centered on the 4861.342 Angstrom hydrogen-beta Fraunhofer line. Optionally, a temperture tuned 6927.00 Angstrom R2 line laser oscillator wavelength from the pink ruby gain medium doped with approximately 0.05% chromium ion relies on frequency doubling the R2 line at 6927.00 Angstrom to 3462.

Abstract: A chromium doped solid-state high peak-power laser transmitter emits at a 4861.342 or 4340.5 Angstrom Fraunhofer line, lines of peak blue-seawater transmission and minimum solar radiation. A pink ruby gain medium doped with approximately 0.05% chromium ion is temperature tuned to an R2 line at 6924.51 Angstrom wavelength and an R1 line is dispersively suppressed in a laser oscillator cavity also tuned to 6924.51 Angstrom. The oscillator is Q-switched and the amplified high peaked-power 6924.51 Angstrom output is hydrogen Raman shifted to the first-Stokes at 9722.684 Angstrom which is frequency doubled to produce a high peak-power output at 4861.342 Angstrom hydrogen-beta Fraunhofer line. Optionally, a temperature tuned R2 line at 6927.00 Angstrom wavelength from the pink ruby gain medium doped with approximately 0.05% chromium ion is Raman shifted 2916 cm.sup.-1 in methane to the first-Stokes at 8681.0 Angstrom. Next, the first-Stokes at 8681.0 Angstrom is frequency doubled to the 4340.