19-core MCF transmission system using EDFA with shared core pumping coupled via free-space optics.

We report the development of a space division multiplexed (SDM) transmission system consisting of a 19-core fiber and 19-core Erbium-doped fiber amplifier (EDFA). A new 19-core fiber with an improved core arrangement was employed to achieve a low aggregated inter-core crosstalk of -42 dB at 1550 nm over 30 km. The EDFA uses shared free-space optics for pump beam combining and isolation, thus is SDM transparent and has some potential for cost reduction.

Glucose sensor with a Sagnac interference optical system.

The angle of optical rotation was measured by detecting the phase difference between clockwise and counterclockwise circular polarized light that propagated in a sensing loop. This polarimeter, or glucose sensor, consisted of a Sagnac interference optical system with a polarization-maintaining optical fiber, so it was not affected by the control limitations of the polarization rotation angle or the optical power fluctuation that occurs with scattered light, reflection, or polarization rotation in an optical system. The angle of rotation was measured from the phase difference of the glucose sensor when the concentration of glucose was changed.