New quasi-cw pyrotechnically pumped crystal lasers

Abstract

Stationary axisymmetric spacetimes containing a pair of oppositely rotating periodically intersecting circular geodesics allow us to study the various socalled 'clock effects' by comparing either observer or geodesic proper time periods of orbital circuits defined by the observer or the geodesic crossing points. This can be extended from a comparison of clocks to a comparison of parallel-transported vectors, leading to the study of special elements of the spacetime holonomy group. The band of holonomy invariance found for a dense subset of special geodesic orbits outside a certain radius in the static case does not exist in the nonstatic case. In the Kerr spacetime the dimensionless frequencies associated with parallel-transport rotations can be expressed as ratios of the proper and average coordinate periods of the circular geodesics. PACS number: 0420C−1/2 ii ∂ i be the orthonormal frame vectors along the time slices (to be referred to as the 'spherical frame'), where i = r, θ, φ. ∂ t and ∂ φ are Killing vector fields associated respectively with stationarity and axisymmetry; ∂ φ has closed orbits φ : 0 → 2π. All considerations below will be limited to the region of spacetime where the one-form dt remains timelike and this lapse-shift decomposition remains valid, namely, outside the (outer) horizon r = r + in the Kerr spacetime, the (outer) surface where N = (−g tt ) −1/2 → 0. Static spacetimes occur as the special case g tφ = 0 = N φ . Explicit values of the various metric quantities for the Kerr spacetime are given in table 1 of [3].

Thermal lens study in diode pumped Ng- and Np-cut Nd:KGd(WO_4)_2 laser crystals

“…According to [22], such a feature in the output power behaviour is observed when the laser resonator, due to the thermal lens induced in the active element, approaches the edge of stability region. Calculations in [22] show that, for the resonator configuration used in the experiment, there are two critical values of the thermal lens refractive power (D c ) 1 = 1/(L-l + ln −1 ) and (D c ) 2 …”

“…Neodymium-doped KGd(WO 4 ) 2 (KGW) is a well known laser material with extensively investigated spectroscopic properties (see [1][2][3][4][5] and references therein). Nd:KGW has good prospects for self-Raman conversion to 1.54 µm [7,8] due to the relatively high emission cross-section at ~1.35 µm (7.6 × 10 −20 cm 2 [6]) also in combination with a high Raman gain coefficient (up to 4.4 cm/GW [1]).…”

LD-pumped actively Q-switched Nd:KLu(WO4)2 self-Raman laser at 1185nm

“…KLuW attracted considerable attention, both spectroscopy and lamp-pumped laser operation of Nd:KLuW were studied [8][9][10][11]. In 1992, Kaminskii et al reported the first demonstration of LD pumped Nd:KLuW laser, obtaining an output power of 105 mW [12].…”