1. Reflective image-providing displays illuminated with chromatically-adjusted holographically diffused light are provided.

2. A holographic planar concentrator of solar energy employing an array of holographically-recorded diffraction grating elements adjoining the corresponding bifacial or monofacial PV-cell.

3. Each mirror has a corresponding astigmatism-corrected, holographically-ruled diffraction grating, each one on a curved substrate so as to produce four 1.65 m (5.4 ft) Rowland circle spectrographs.