Programmable spectral phase coding of an amplified spontaneous emission light source

The use of a programmable pulse shaper for spectral phase coding of broadband incoherent light is discussed. Our experiments result in tailoring of the electric field cross-correlation function between the shaped and the original unshaped light. This technique is illustrated through several examples, including binary spectral phase filtering, gray-level spectral phase filtering using quadratic-residue codes, generation of coherence functions consisting of trains of coherence peaks via periodic gray-level phase coding, and dispersion compensation for broadband incoherent light. Spectral interferometry measurements of phase coded incoherent light are also presented. Based upon careful alignment of the pulse shaper, we were able to obtain excellent agreement between the experiments and theoretical simulations. In some cases we found that the usual assumption of a linear spectral dispersion at the masking plane of the pulse shaper led to distortion in the shaped correlation functions. Here we demonstrate the ability to measure the exact spectral dispersion, which is then taken into account when programming the spectral phase modulation. This removes the observed distortion, leading once again to excellent agreement between theory and experiment. q 1999 Elsevier Science B.V. All rights reserved.