CommOptics has introduced a new, single mode fiber (SMF-28) collimating lens that delivers the precision focusing necessary to support telecommunications applications at OC-192 and above.
The lens enables precise focus to be achieved by positioning a fiber 250 µm from input surface of the lens, which is wedged to eliminate back reflections. Specifically, this 2.9 mm focal length, 1.8 mm diameter lens is produced with a focal length tolerance of ±0.1 percent. In contrast, commonly available fiber coupling lenses based on gradient index technology exhibit a focal length variation of as much as 3 percent, creating a coupling loss of in excess of 1 dB. (Consequently, gradient index lenses must often be individually repolished to move the point of focus to the correct position so as to achieve the fiber coupling required for efficient operation at 10 Gb/s or beyond.)
The lenses are supplied with an antireflection coating for C Band operation and deliver an insertion loss less than 0.5 dB; coatings for the S or L Bands are also available on request. An athermalized version, which maintains focus over a -20°C to 70°C temperature range, is also available.
CommOptics designs and manufactures high precision micro-optics, and precision housings and sub-assemblies for telecommunications applications. For more information, visit www.commoptics.com.