We have measured the phase matching directions for second harmonic generation and dif- ference-frequency generation in the nonlinear crystal cdSip2 , at infrared wavelengths up to 9.5 μm. By a simultaneous fit to all the angular data, the wavelength dependence of the ordinary and extraordinary principal refractive indices were refined over the entire transparency range of the crystal. This work shows the capability of cdSip2 for broadband generation of mid-infrared light. Full text