Measurement of the coupling constant in a two-frequency VECSEL

Abstract: We measure the coupling constant between the two perpendicularly polarized eigenstates of a two-frequency Vertical External Cavity Surface Emitting Laser (VECSEL). This measurement is performed for different values of the transverse spatial separation between the two perpendicularly polarized modes. The consequences of these measurements on the two-frequency operation of such class-A semiconductor lasers are discussed

Synthesis and Characterization of Dialkylaluminum Amidates and Their Ring-Opening Polymerization of ε-Caprolactone

The stoichiometric reactions of N-(2-methylquinolin-8-yl) (R)amides (L1–L8; L1, R = Ph; L2, R = p-FPh; L3, R = p-ClPh; L4, R = p-(MeO)Ph; L5, R = o-MePh; L6, R = p-MePh; L7, R = Me; L8, R = CF3) with Me3Al afforded the corresponding dimethylaluminum amidate complexes [Me2AlL] (C1–C8). The treatment of N-(2-methylquinolin-8-yl)picolinamide (L9) with 1 or 2 equiv of Me3Al formed Me2AlL9 (C9) or Me2AlL9·Me3Al (C10), respectively; meanwhile, the stoichiometric reaction of L9 with iBu3Al gave iBu2AlL9 (C11). All organoaluminum amidate complexes were fully characterized by 1H/13C NMR spectroscopy and elemental analysis, and the unambiguous structures of complexes C2, C4, C9, and C11 were further determined by single-crystal X-ray diffraction. With the assistance of 1 equiv of BnOH, all dialkylaluminum amidate complexes showed appreciable activities toward the ring-opening polymerization of e-caprolactone and produced polycaprolactones with narrow polydispersity; the nature of the active species was also investigated