1 May 1993 Optical amplifiers and liquid-crystal shutters applied to electrically reconfigurable fiber optic signal processors
Author Affiliations +
Abstract
We demonstrate the application of optical amplifiers and polymer-dispersed liquid-crystal (PDLC) shutters to electrically reconfigurable fiber optic delay line signal processors. Two 8-tap finite impulse response (FIR) fiber filter modules were fabricated. These two modules can also be interconnected in a cascaded or parallel configuration to implement a 16-tap fiber FIR filter. An erbium-doped fiber amplifier with a peak gain of about 20 dB was used to compensate for the large optical losses involved in the filters due to the large tap numbers. The relatively inexpensive PDLCs were used to realize electrically reconfigurable analog tap weights. The individual fiber filters were then evaluated for their impulse and frequency responses. The fabricated filters used single-mode fibers and fiber components and were polarization independent to within 0.5 dB. The sampling frequency was about 200 MHz, which can easily be upgraded into the gigahertz range. The tapping extinction ratio was about 13 dB with subkilohertz tunability speed. The amplified spontaneous emission noise can limit the filtering performance unless appropriate spectral filtering is included before detection. These optically amplified electrically reconfigurable fiber signal processors have the potential to lead to the realization of complex programmable and adaptive optical systems.
Behzad M. Moslehi, Behzad M. Moslehi, Kelvin K. Chau, Kelvin K. Chau, Joseph W. Goodman, Joseph W. Goodman, } "Optical amplifiers and liquid-crystal shutters applied to electrically reconfigurable fiber optic signal processors," Optical Engineering 32(5), (1 May 1993). https://doi.org/10.1117/12.133300 . Submission:
JOURNAL ARTICLE
8 PAGES


SHARE
RELATED CONTENT

A reconsideration of birefringent interleaver
Proceedings of SPIE (February 19 2007)
Null shifting with fixed delays
Proceedings of SPIE (May 31 1990)
Improved FFT-based algorithm for GPS signal acquisition
Proceedings of SPIE (October 12 2008)
NLMS-based PMD equalization with improved adaption speed
Proceedings of SPIE (January 22 2010)
Low noise fiber laser based on gain feedback in a...
Proceedings of SPIE (February 15 2012)

Back to Top