  We construct single input logic gates using the energy sharing collisions of
a minimal number of (three) bright optical solitons associated with the three
soliton solution of the integrable Manakov system. As computation requires
state changes to represent binary logic, here we make use of the state change
of a particular soliton during its sequential collision with other two solitons
for constructing single input gates. As a consequence, we clearly demonstrate
the construction of various one-input logic gates such as COPY gate, NOT gate
and ONE gate using energy sharing three soliton collision of Manakov system.
This type of realization of logic gates just from a three soliton collision
(pair-wise interaction) is clearly distinct from the earlier studies which
require separate collisions of four solitons.
