BIRKERØD, Denmark, Feb. 10, 2011 — The DC-200-40-PZ-YB-03 manufactured by NKT Photonics A/S is a rare-earth-doped ytterbium fiber. The patented polarizing double-clad fiber with coil control features a mode area of more than 650 µm2 while maintaining single-mode beam quality. Because it is polarizing, it delivers an improved polarization extinction ratio compared to polarization-maintaining fibers, according to the company. The multimode pump light is guided by proprietary air-clad technology, ensuring low loss, a high damage threshold and a large numerical aperture that relaxes tolerances on coupling optics and facilitates the use of lower brightness diodes. Used by industrial fiber laser manufactures, it is available with sealed ends or with end caps and high-power SMA connectors in the company’s aeroGain Flex range. The coil control ensures that the fiber always coils in the correct plane, resulting in good mode stability and ease of use. The company recommends a bending diameter in the range of 25 to 40 cm and says that the best polarization extinction ratio is obtained when operating the fiber in the slow axis. Advantages of single-mode fiber include better output stability, high beam quality, no requirements on tight coiling and no coiling-induced mode area compression. Signal core diameter is 40 ±2 µm, inner cladding diameter is 200 ±5 µm, outer cladding diameter is 450 ±20 µm, and coating diameter is 620 ±30 µm. Inner and outer cladding material is pure silica, and the coating material is single-layer HT acrylate. Applications include high-pulse-energy fiber amplifiers and fiber lasers.