Evanescent Optics Model 905P Variable Ratio Polarization-Maintaining Fiber Coupler

The 905P from Evanescent Optics is a premium-grade, manual variable-ratio fiber-optic coupler designed for polarization-maintaining (PM) systems. Using evanescent-wave coupling between optically-contacted polished fibers, this unit allows precise adjustment of the splitting ratio from ~0 %–99 % while maintaining excellent optical performance: <0.15 dB excess loss, typical ≥24 dB polarization isolation, and broadband operation from ~0.75 µm into the 2 µm region.

The device is housed in a compact 31 × 46 × 69 mm aluminum body with a micrometer-lever adjustment arrangement (25:1 ratio) yielding ~1 µm motion per 0.001″ micrometer step. Standard pigtails (1 m length) are sleeved in 900 µm HYTREL.  Connectors include FC/SPC, FC/APC, LC/APC, SC/APC or SC/PC (keying to slow axis standard, fast axis on request).

Ideal for laser delivery, interferometry, fiber-optic sensing, polarization-diversity receivers, and other advanced photonics applications where tunable coupling and polarization integrity are critical.