A highly integrable, compact, reliable, and low‐WDL fiber‐optic tap coupler

Abstract

AbstractIn this paper, a highly integrable, compact, reliable, and low wavelength dependent loss (WDL) fiber‐optic tap coupler is presented. The coupler includes a single‐fiber collimator at the input end, a grating beam deflector, a housing, and a specially designed dual‐fiber collimator at the output end. One fiber of the dual‐fiber collimator serves as the output channel and the other fiber serves as the tap channel. To minimize WDL induced by the wavelength‐dependent diffraction efficiency of the phase grating, this dual‐fiber collimator is carefully designed so that wavelength‐dependent diffraction efficiency is largely compensated by the wavelength‐dependent coupling efficiency of the dual‐fiber collimator. A low WDL as small as 0.05 dB is achieved within the whole c‐band region. The tap ratio can also be adjusted by controlling the modulation depth of the diffraction grating. Since this unique coupler can be easily integrated with other fiber‐optic elements, such as variable optic attenuators (VOAs), it can be used to build a variety of fiber‐optic modulates with integrated power monitoring capability. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 166–170, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10710