Doubling of bandwidth utilization using two orthogonal polarizations and power unbalancing in a polarization-division-multiplexing scheme

Automatic All-Optical Detection in Polarization-Division-Multiplexing System Using Power Unbalanced Transmission

“…Moreover, tracking the polarization state of the data channels is usually necessary and not trivial. Reported approaches for the receiver design include: (i) monitor of clock tone or pilot tones [3][4][5][6] (ii) multi-level electronic detection [7][8], and (iii) crosstalk correlation [9]. Each of these schemes has one of the following drawbacks: (i) requiring high-speed electronics, thereby making it bit-rate dependent; (ii) additive system power penalties; and (iii) requiring modification or even significant re-design of the existing transceiver line card.…”

“…One method for doubling the spectral efficiency and system capacity is polarization-division-multiplexing (PDM), in which two independently modulated data channels located at the same wavelength are simultaneously transmitted on orthogonal polarization states of the fiber [2][3][4][5][6][7][8][9]. For systems with low PMD and PDL, PDM might also provide a path for upgrading existing links [10].…”

Narrowband 2/spl times/10 Gbit/s quaternary intensity modulation based on duobinary modulation in two polarizations with unequal amplitudes

“…Higher spectral efficiency can be achieved by doubling the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all [2,3,4,5,6,7]. The spectral efficiency can be improved even more by using duobinary modulation in two quadratures generating a 9 constellation point quaternary intensity modulation signal (9-QAM) [8].…”

Achieving Arbitrary Control over Pairs of Polarization States Using Complex Birefringent Metamaterials

“…For example, with this capability one can map two polarizations that are close to each other into two orthogonal polarizations, which may facilitate the detection of small polarization changes, such as those arising from the imaging of biological tissues [8,9] and thin films [10]. Likewise, the ability to completely separate nonorthogonal polarization states could enable new multiplexing schemes in optical communications networks beyond what is currently possible [11,12].We first show that the key step for achieving arbitrary control over pairs of polarization states is to develop a class of meta-materials which are capable of performing the following polarization transformation as denoted byHere we assume propagation along the z-axis, and label the polarization states in terms of the electric field components in the xy-plane as |E x , E y . | ± θ denote the two polarization states that lie on the great circle of the Poincaré sphere passing through |1, i and |1, 1 , and are symmetrically placed away from |1, i , subtending an angle of ±θ with respect to |1, i .…”

“…For example, with this capability one can map two polarizations that are close to each other into two orthogonal polarizations, which may facilitate the detection of small polarization changes, such as those arising from the imaging of biological tissues [8,9] and thin films [10]. Likewise, the ability to completely separate nonorthogonal polarization states could enable new multiplexing schemes in optical communications networks beyond what is currently possible [11,12].…”