Fiber Optics & Photonics Guides

Polarization extinction ratio (PER) is a key performance metric for polarization-maintaining fiber, pigtails, patch cords, laser systems, interferometers, and polarization-sensitive photonic components. Expressed in decibels, it compares optical power in the intended polarization axis with power that has coupled into the orthogonal axis. A higher PER generally indicates cleaner polarization separation—but a meaningful specification must

Polarization maintaining fiber (PM fiber or PMF) is a specialty optical fiber engineered to preserve the orientation of linearly polarized light. It is used when polarization stability directly affects measurement accuracy, signal quality, interferometric visibility, or laser performance. For buyers, the correct PM fiber is not selected by wavelength alone: fiber geometry, beat length, polarization

Photonic crystal fiber (PCF) is a microstructured optical fiber that uses a precisely arranged pattern of longitudinal air holes to control light guidance, dispersion, mode area, birefringence and nonlinear interaction. Depending on the core design, a PCF can guide light in solid silica through modified total internal reflection or in a hollow core through anti-resonant