All-optical phase and delay spectral encoding of signals with advanced modulation formats

Double all-optical encryption of M-QAM signals based on spectrally sliced encoding keys

“…Herewith, we extend our previous analyses [5,6] by doubling the encoding-decoding stages applied on spectral slices obtained by optical band-pass filters (OBPFs) having identical 3-dB bandwidths. Encoding is done by independently applying a precise amount of phase-shift and delay making to each slice, which makes the signal data meaningless until the signal recovery is applied.…”

“…Nevertheless, the investigated technique could also be applied to signals with other bit rates and modulation formats as in our previous work [5,6]. To investigate the sensitivity performance, we initially simulated the single-encoding Figure 3(a) shows the spectrum for the sliced signal, whereas Fig.…”

“…With the constant need for optical network security to address the vulnerability of high amount of data [1,2], cryptographic techniques were pushed to go beyond the electronic domain and implemented on physical/photonic layer [3][4][5]. The possibility to encrypt data in optical domain has attracted more attention recently due to its compatibility with transparent optical networks (TON) where no O-E-O conversions are implemented.…”

“…The SPE approach has shown effective protection on optical CDMA (OCDMA) channels, but may not be suitable for systems with high number of WDM channels. On the other side, the encoding of spectrum slices have been a technique showing a high potential for optical encryption of WDM signals with different modulation formats, [5,6].…”