An improved approach for narrow-band wavelength selection in tunable lasers is described. To provide the tunability, a reconfigurable diffractive optical element (DOE) based on a programmable spatial light modulator (PSLM) is applied. With a proper choice of the phase transfer function of the PSLM, the device can be used as a dispersive intra-cavity component for precise tuning within the lasing spectral band of a solid-state dye laser. The suggested design allows avoiding the mechanical movement of any cavity components. The tunability performance and simulation are demonstrated using the Fourier optics method.