The present invention provides optical fiber coating systems and coated optical
fibers having hydrophilic primary coatings. According to one embodiment of the
invention, a coated optical fiber includes an optical fiber having a core and a
cladding; a hydrophilic primary coating encapsulating the optical fiber, the primary
coating having a Young's modulus less than about 2 MPa; and a secondary coating
encapsulating the primary coating, wherein the primary coating exhibits substantially
no water bubble formation and substantially no delamination when the coated optical
fiber is soaked in water at 23 C. for 30 days.