A novel packet format with non-return-to-zero (NRZ) label and duobinary carrier-suppressed return-to-zero (DCS-RZ) payload is proposed for optical packet switching networks. NRZ label is followed by DCS-RZ payload with a certain guard time. The spectra of the low-rate NRZ label locate around the optical carrier frequency where some parts of the corresponding spectra of the high-rate DCS-RZ payload have been suppressed due to DCS-RZ modulation. At the switching node, the label or payload extraction can be realized simply through an optical bandpass or notch filter respectively. The feasibility of the scheme is verified by the simulation on the famous photonic design platform designed by Virtual Photonics Inc. (VPI). The effects of optical filter bandwidth on the received signal quality are discussed by analyzing bit error rate (BER) and contrast ratio performances.