Title :
Design of high-performance all-fiber spectral filter with weighted coupling
Author :
Chao, Shih-Chieh ; Wu, Mu-Shiang
Author_Institution :
Dept. of Electr. Eng., Tatung Inst. of Technol., Taipei, Taiwan
fDate :
10/1/1994 12:00:00 AM
Abstract :
Narrow-band and low-sidelobe all-fiber spectral filters are achievable with directional couplers constructed with W-index and step-index fibers. The sidelobe levels can be reduced significantly by properly weighting the coupling strength along the device. We provide numerical simulations in which the different weighting functions are obtained via a variable intercore separation. With a Gaussian function weighting, -38 dB transfer response sidelobes have been obtained, which is more than 29 dB reduction over the uniform coupling case. Some design rules for obtaining filters with desired bandwidths and coupling lengths are also given. These results can be very useful in the design of high-performance all-fiber filters for wavelength multiplexing
Keywords :
directional couplers; multiplexing equipment; optical communication equipment; optical couplers; optical fibres; optical filters; refractive index; wavelength division multiplexing; Gaussian function weighting; W-index; bandwidths; coupling lengths; coupling strength; design rules; directional couplers; high-performance all-fiber filters; high-performance all-fiber spectral filter; low-sidelobe all-fiber spectral filters; narrow-band all-fiber spectral filters; numerical simulations; sidelobe levels; step-index fibers; transfer response sidelobes; uniform coupling case; variable intercore separation; wavelength multiplexing; weighted coupling; weighting functions; Bandwidth; Chaos; Directional couplers; Filters; Insertion loss; Narrowband; Optical fiber couplers; Optical fiber devices; Propagation losses; Wavelength division multiplexing;
Journal_Title :
Lightwave Technology, Journal of
