Abstract: Optical detection apparatus and process which, in its optimum configuration, utilizes holographic optical elements both as a dichroic beamsplitter and as a selective notch-type barrier filter to enhance the amount of light to reach the detector while barring undesirable wavelengths from reaching the detector. The apparatus, when incorporated into a fluorescent-light detecting process, has the advantage of minimizing loss of light suffered because of a small Stokes shift, which shift occurs between the wavelength of the light transmitted to a sample target area and the increased wavelength of fluorescent light emitted from the sample for collection by a detection device.