A fiberoptic sensing apparatus comprises a fiberoptic coupler in which a plurality
of optical fibers are joined through a fused coupling region, the optical fibers
including at least one input optical fiber and a plurality of output optical fibers,
the fiberoptic coupler distributing light incident to the input optical fiber among
the plurality of output optical fibers. The coupler is mounted to a support member
and configured such that at least a portion of the coupling region can be deflected
to change the light distribution among the output fibers without putting the coupling
region under tension. A fluid column is cooperative with a deflection member disposed
to deflect the portion of the coupling region.
