Title: Towards fully commercial, UV-compatible fiber patch cords,
Abstract: We present and analyze two pathways to produce commercial optical-fiber patch
cords with stable long-term transmission in the ultraviolet (UV) at powers up
to $\sim$ 200 mW, and typical bulk transmission between 66-75\%. Commercial
fiber patch cords in the UV are of great interest across a wide variety of
scientific applications ranging from biology to metrology, and the lack of
availability has yet to be suitably addressed. We provide a guide to producing
such solarization-resistant, hydrogen-passivated, polarization-maintaining,
connectorized and jacketed optical fibers compatible with demanding scientific
and industrial applications. Our presentation describes the fabrication and
hydrogen loading procedure in detail and presents a high-pressure vessel
design, calculations of required \Ht\ loading times, and information on patch
cord handling and the mitigation of bending sensitivities. Transmission at 313
nm is measured over many months for cumulative energy on the fiber output of >
10 kJ with no demonstrable degradation due to UV solarization, in contrast to
standard uncured fibers. Polarization sensitivity and stability are
characterized yielding polarization extinction ratios between 15 dB and 25 dB
at 313 nm, where we find patch cords become linearly polarizing. We observe
that particle deposition at the fiber facet induced by high-intensity UV
exposure can (reversibly) deteriorate patch cord performance and describe a
technique for nitrogen purging of fiber collimators which mitigates this
phenomenon.