High-brightness wavelength-beam-combined diode laser stacks using a volume Bragg grating (VBG)
Using VBG-stabilized wavelength beam combining of 3-bar diode laser stack, we demonstrate 89.5 W CW with beam quality M2 ~ 26 in the slow-axis and M2~21 in the fast-axis. The beam combining efficiency is 75%.
Spectral beam combining of a broad-stripe diode laser array in an external cavity
The outputs from an 11-element, linear diode laser array with broad stripes have been beam combined into a single beam with a beam quality of ∼20× diffraction limited in the plane of the junction. This beam combining was achieved by use of a common external cavity containing a grating, which simultaneously forces each array element to operate at a different, but controlled, wavelength and forces the beams from all the elements to overlap and propagate in the same direction. The power in the combined beam was 50% of the output from the bare laser array.
5.63 and 5.80 MeV levels of Ne20; de-excitation branching
Abstract The ratio Г γ /Г for the 5.63 and 5.80 MeV levels of Ne 20 has been determined to be 0.077 (±0.008) and −4 , respectively, by using the C 12 (C 12 , α)Ne 20 reaction and determining the fraction of the events in which the alpha-particle and the Ne 20 recoil are present in coincidence at the kinematically correct angles. In both cases these results in themselves are shown to imply radiative E1 transition (5.63→1.63 and 5.80→0, respectively) probabilities ⪡5 × 10 −5 Weisskopf units. When taken together with the life-time for the 5.63 MeV level measured by Evans et al . values of Г( E1 ) ≲ 5 × 10 −6 and Г α ≈ 6% of the particle estimate are obtained for this state.