Abstract: Radiation from a VBG-locked diode-laser at a locked wavelength of 878.6 nm is focused into a 30-mm long Nd:YVO4 optical amplifier crystal for optically pumping the crystal (24). The crystal amplifies a beam of seed-pulses from a fiber MOPA (12). The power of pump radiation is about 75 Watts. The radiation is focused into a beam-waist having a minimum diameter of about 600 micrometers. This provides an amplifier having a high gain-factor well over 100. The high-gain factor provides a gain-shaping effect on the seed-pulse beam which overcomes thermal aberrations inherent in such high-power pumping, thereby producing an amplified seed-pulse beam with M2 less than 1.3.

Abstract: Radiation from a VBG-locked diode-laser at a locked wavelength of 878.6 nm is focused into a 30-mm long Nd:YVO4 optical amplifier crystal for optically pumping the crystal (24). The crystal amplifies a beam of seed-pulses from a fiber MOPA (12). The power of pump radiation is about 75 Watts. The radiation is focused into a beam-waist having a minimum diameter of about 600 micrometers. This provides an amplifier having a high gain-factor well over 100. The high-gain factor provides a gain-shaping effect on the seed-pulse beam which overcomes thermal aberrations inherent in such high-power pumping, thereby producing an amplified seed-pulse beam with M2 less than 1.3.

Abstract: A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium and a selectively variable attenuator, but not the optical switch. The optical switch and the variable attenuator are cooperatively controlled in response to repeated trigger-signals such that the amplifier delivers corresponding amplified pulses each having about the same energy independent of repetition frequency of the signals below some predetermined value.

Abstract: A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium but not the optical switch. When the primary resonator is closed by the optical switch, and pulses are not being amplified, CW radiation is generated in the secondary resonator and prevents the gain-medium from being saturated. When the optical switch is operated to cause the primary resonator to amplify pulses, generation of CW radiation in the secondary resonator ceases.

Abstract: A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium and a selectively variable attenuator, but not the optical switch. The optical switch and the variable attenuator are cooperatively controlled in response to repeated trigger-signals such that the amplifier delivers corresponding amplified pulses each having about the same energy independent of repetition frequency of the signals below some predetermined value.

Abstract: In traveling-wave ring-resonator an optically nonlinear crystal for converting visible radiation to ultraviolet (UV) radiation has an input face and two output faces. The visible light propagates through the crystal from the input face to one of the output faces. That output face is coated with a dichroic optical coating that transmits unconverted visible light and reflects the ultraviolet light. The reflected ultraviolet light exits the optically nonlinear crystal via the other output face and is coupled out of the resonator at an angle to the resonator axis.

Abstract: A regenerative amplifier includes a gain-medium that is optically pumped by CW radiation. The amplifier has primary resonator for amplifying pulses. The primary resonator has an optical switch for opening and closing the primary resonator. The amplifier has a secondary resonator that includes the gain-medium but not the optical switch. When the primary resonator is closed by the optical switch, and pulses are not being amplified, CW radiation is generated in the secondary resonator and prevents the gain-medium from being saturated. When the optical switch is operated to cause the primary resonator to amplify pulses, generation of CW radiation in the secondary resonator ceases.

Abstract: In traveling-wave ring-resonator an optically nonlinear crystal for converting visible radiation to ultraviolet (UV) radiation has an input face and two output faces. The visible light propagates through the crystal from the input face to one of the output faces. That output face is coated with a dichroic optical coating that transmits unconverted visible light and reflects the ultraviolet light. The reflected ultraviolet light exits the optically nonlinear crystal via the other output face and is coupled out of the resonator at an angle to the resonator axis.