TY - JOUR AU - A. Lytle AU - Xiaoshi Zhang AU - R. Sandberg AU - O. Cohen AU - Henry Kapteyn AU - Margaret Murnane BT - Optics Express DA - 2008-01 DO - 10.1364/OE.16.006544 PY - 2008 EP - 6544 T2 - Optics Express TI - Quasi-phase matching and characterization of high-order harmonic generation in hollow waveguides using counterpropagating light VL - 16 ER -