Multi-order diffractive optical elements for achromatic interconnections at 1.30 mu m and 1.55 mu m

We propose a class of diffractive components allowing free-space optical systems to operate at the two telecommunication wavelengths simultaneously. These are fifth order diffractive components working at the sixth order at 1.30 mu m and at the fifth order at 1.55 mu m. Simulation results showing the link efficiency between two single-mode fibres as a function of the wavelength are presented. The width of the two transmission windows depends on the architecture of the whole system, which must be designed in accordance with technological realizability. (C) 1997 Elsevier Science B.V.