The diffraction efficiency of a recorded Holographic optical element changes with change in wavelength of reconstruction wave even for on-Bragg angle reconstruction. Diffraction efficiency also falls with change in angle of reconstruction with respect to Bragg angle for reconstruction wave of a given wavelength. Therefore, to achieve appreciable diffraction efficiency operation of Holographic Optical Elements at different operating wavelengths, processing parameters namely film-thickness (d), depth of refractive index modulation (Δn), and fringe spacing (ᴧ) must be optimized accordingly. In present work thickness (d) of the film of the recording medium, depth of refractive index modulation (Δn), and fringe spacing (ᴧ) have been optimized for holographic optical elements to be recorded in dichromated gelatin medium to achieve maximum efficiency operation for three different optical transmission windows 800–900 nm, 1250 – 1350 nm and 1500–1600 nm operating at wavelengths 850 nm, 1310 nm, and 1550 nm respectively. A pair of such designed holographic optical elements can advantageously be used for coupling laser light from one fiber end to another fiber end. It is further shown that a single coupler consisting of properly designed holographic optical elements may be used for optical transmission windows 1250–1350 nm and 1500–1600 nm operating at wavelengths 1310 nm, and 1550 nm respectively.