A linearly configured fiber-optic acoustic sensor has been developed b
y embedding a single-mode fiber in a polyurethane cylindrical layer. T
he acoustic sensitivity was studied in the range of 0.75-10 KHz and wa
s found to be frequency independent and significantly higher than that
of a free suspended fiber or a solid mandrel fiber sensor. A comparis
on is made between this sensor and air backed fiber-optic mandrel sens
ors.