In this paper, we present a novel noise resistent diagonal iteration-based carrier interferometry (DICI) codes for spreading optical orthogonal frequency-division multiplexing (OOFDM) symbols, and thereby suppressing the peak to average power ratio (PAPR) for high data rate OOFDM based systems. Considering that the high date rate transmission requires the subcarrier number to be large, and that the large subcarrier number may induce smaller intervals between the symbols and higher PAPR and thus leading to the performance degradation, we propose to use DICI codes to enlarge the intervals and suppress the noises including the signal- dependent noises in intensity modulated system and the phase noises in coherent modulated systems to improve the performances. More explicitly, we perform the diagonal iteration on the carrier interferometry (CI) codes by calculating the Kronecker product of identity matrix and CI code matrix, thus the matrix extension is achieved by the DICI codes. Moreover, we prove that the presented DICI codes are orthogonal and invertible. Simulations are performed and the results demonstrate the outstanding bit error rate (BER) and PAPR performances of the proposed DICI-aided spreading OOFDM systems.