Nhng tin b trong Quang hc, Quang ph và ng dng VI ISSN 1859 - 4271
Nhng tin b trong Quang hc, Quang ph và ng dng VI ISSN 1859 - 4271
Nhng tin b trong Quang hc, Quang ph và ng dng VI ISSN 1859 - 4271
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Advances in Optics, Photonics, Spectroscopy & Applications <strong>VI</strong> <strong>ISSN</strong> <strong>1859</strong> - <strong>4271</strong>propagation: B=(2π/λ)∫[n 2 I(z)/n 0 ]dz where z is the distance alo<strong>ng</strong> the laser propagation.Comparison of these parameters for a Nd-doped silicate laser glass and a Nd-doped <stro<strong>ng</strong>>ph</stro<strong>ng</strong>>os<stro<strong>ng</strong>>ph</stro<strong>ng</strong>>atelaser glass shows that the <stro<strong>ng</strong>>ph</stro<strong>ng</strong>>os<stro<strong>ng</strong>>ph</stro<strong>ng</strong>>ate laser glass has more than a factor of 2 higher figure of meritthan the silicate laser glass. This means that twice higher power can be generated with the lasersystem with similar configurations.Fig. 4. Layout of the G-MII glass laser.[7]This estimation was validated by the performance of the G-MII laser which is the first largeaperture Nd-<stro<strong>ng</strong>>ph</stro<strong>ng</strong>>os<stro<strong>ng</strong>>ph</stro<strong>ng</strong>>ate glass laser, developed based on the preliminary development of a smallerscale Nd-<stro<strong>ng</strong>>ph</stro<strong>ng</strong>>o<stro<strong>ng</strong>>ph</stro<strong>ng</strong>>ate glass laser [8]. The near field patterns of the output laser beam of G-MII atdifferent laser energies at the laser pulse width of 100 ps are shown in Fig. 5 [7]. These beampatterns show that local intensification of the laser beam due to nonlinear self focusi<strong>ng</strong> is nots<stro<strong>ng</strong>>tro<strong>ng</strong></stro<strong>ng</strong>> even at the output power of 3.4 TW. This power is far higher than the ~1 TW outputpower obtained with the Nd:silicate glass lasers of similar apertures that were common at thattime.Fig. 5. Near field patterns of G-MII output beam [7].22