• Polarization Maintaining (PM)
• Polarization Extinction Ratio (PER) >20 dB over 100 m
• Mode Field Diameter Independent of Wavelength
• Undoped Pure Silica Core and Cladding

This fiber is Endlessly Single Mode (ESM), it has a Large-Mode-Area (LMA), and it is a PM Photonic Crystal Fiber (PCFs). A conventional single mode fiber is actually multimode for wavelengths shorter than the second-mode cutoff wavelength, limiting the useful operating wavelength range in many applications. In contrast, Crystal Fiber's endlessly single mode PCFs are truly single mode at all wavelengths for which fused silica is transparent.

In practice, the useful operating wavelength range is limited only by bend loss. Although the cladding possesses six-fold symmetry, the mode profile is very similar to the quasi-Gaussian fundamental mode of a conventional, axially symmetric, step-index fiber, resulting in a form overlap that is >90%. Unlike conventional fiber, this fiber is fabricated from a single material: undoped, high-purity, fused silica glass. The PM performance is achieved via stress rod applied birefringence. The combination of material and very large mode area enables high power levels to be transmitted through the fiber without material damage or the adverse effects caused by the fiber's nonlinear properties.

• Mode Field Diameter: 8.0 ± 0.8 µm
• Attenuation: <30 dB/km @ 470 nm, <5 dB/km @ 1060 nm, <5 dB/km @ 1550 nm
• Numerical Aperture: 0.10 ± 0.05 @ 1060 nm
• Cut-off Wavelength: None
• Signal Core Diameter: 10.0 ± 1 µm
• Outer Cladding Diameter: 230 ± 5 µm
• Coating Diameter: 350 ± 10 µm
• Cladding Material: Pure Silica
• Coating Material: Acrylate, Single Layer