A diode-pumped, prismless Nd:glass laser oscillator, mode-locked by a semiconductor saturable absorber, was stabilized against self-Q-switching by using a phase-mismatched second harmonic crystal. Furthermore, negative-index cascaded second-order nonlinearity provided the soliton shaping mechanism with normal intracavity dispersion. Nearly Fourier-limited pulses as short as 520 fs were obtained.