The (A) over tilde (1)A(2) states of H2CGe and D2CGe have been explored for the first time by (A) over tilde-(X) over tilde laser-induced fluorescence (LIF) spectroscopy of the orbitally forbidden S-1-S-0 transition and stimulated emission pumping (SEP) and wavelength resolved fluorescence studies of the allowed (B) over tilde-(A) over tilde electronic transition. Medium-resolution SEP studies gave the excited (A) over tilde state nu(2), nu(3), nu(4), and nu(6) vibrational frequencies for (H2CGe)-Ge-74 and (D2CGe)-Ge-74. The 4(1) and 6(1) levels and higher combination and overtone states are strongly Coriolis coupled, which perturbs the rotational subband structure, limiting the accuracy of the determination of the vibrational frequencies. High-resolution SEP studies of the (B) over tilde-(A) over tilde 0(0)(0) band have allowed us to determine the rotational constants of the (A) over tilde state of (H2CGe)-Ge-74, from which we were able to calculate an approximate r(0) structure with the CH bond length constrained to the ground state value. The zero-point level of (D2CGe)-Ge-74 is substantially perturbed, most plausibly by interaction with an excited vibrational level of the nearby triplet ((a) over tilde (3)A(2)) state. (C) 2004 American Institute of Physics.