  We investigate linear interference of a plane wave with different localised
waves using coupled Fokas-Lenells equation(FLE) with four wave mixing (FWM)
term. We obtain localised wave solution of the coupled FLE by linear
superposition of two distinctly independent wave solutions namely plane wave
and one soliton solution & plane wave and two soliton solution. We obtain
several nonlinear profiles depending on the relative phase induced by soliton
parameters. We analyse the linear interference profile under four different
conditions on the spatial and temporal phase coefficients of interfering waves.
We further investigate the interaction of two soliton solution and a plane
wave. In this case we notice that asymptotically, two solitons profile may be
similar or different from each other depending on the choices of soliton
parameters in the two cases. The results obtained by us might be useful for
applications in soliton control, a fiber amplifier, all optical switching, and
optical computing. Further we believe that the present investigation would be
useful to study the linear interference pattern of other localised waves of
FLE.
