  Continuous variable entanglement can be produced in nonlinear systems or via
interference of squeezed states. In many of optical systems, such as parametric
down conversion or interference of optical squeezed states, production of two
perfectly symmetric subsystems is usually used for demonstrating the existence
of entanglement. This symmetry simplifies the description of the concept of
entanglement. However, asymmetry in entanglement may arise naturally in a real
experiment, or be intentionally introduced in a given quantum information
protocol. These asymmetries can emerge from having the output beams experience
different losses and environmental contamination, or from the availability of
non-identical input quantum states in quantum communication protocols. In this
paper, we present a visualisation of entanglement using quadrature amplitude
plots of the twin beams. We quantitatively discuss the strength of asymmetric
entanglement using EPR and inseparability criteria and theoretically show that
the optimal beamsplitter ratio for entanglement is dependent on the asymmetries
and may not be 50/50. To support this theory, we present experimental results
showing one particular asymmetric entanglement where a 0.78/0.22 beamsplitter
is optimal for observing entanglement.
