Patent ID: 11880083
Assignee: CORNING RESEARCH & DEVELOPMENT CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical fiber cable comprising:
a cable jacket having an inner jacket surface and an outer jacket surface, wherein the outer jacket surface is an outermost surface of the optical fiber cable and wherein the inner jacket surface defines an internal jacket bore;
at least one subunit disposed within the internal jacket bore, each of the at least one subunit comprising:
a foamed tube, the foamed tube having an inner subunit surface and an outer subunit surface, the inner subunit surface defining a central subunit bore, wherein the foamed tube is characterized by at least one of:
a closed-cell morphology having pores with an average effective circle diameter of 300 μm or less;
a compression set of no more than 20% as measured after compression to a strain of 50% for ten hours and after four hours of recovery time using a parallel plate compression fixture on a dynamic mechanical analyzer, or
a compression modulus of less than 3 MPa when measure at 50% strain as measured according to ASTM 3574, and

a stack of at least two optical fiber ribbons disposed in the central subunit bore of the foamed tube, each of the at least two optical fiber ribbons comprising at least two optical fibers;

wherein the stack occupies from 85%-95% of a cross-sectional area of the central subunit bore such that the central subunit bore provides from 5% to 15% of free space around the stack along at least a portion of a length of the foamed tube.