Optical: systems and elements – Deflection using a moving element – Using a periodically moving element
Patent
1996-02-23
1997-12-16
Pascal, Leslie
Optical: systems and elements
Deflection using a moving element
Using a periodically moving element
359161, 359181, 359187, 359239, H04B 1004
Patent
active
056991797
ABSTRACT:
A phase modulator is provided in an externally modulated, feed-forward linearized, analog cable television (CATV) link for reducing fiber-induced composite second order (CSO) distortion components. The system is compatible with existing commercially available modulators. CSO distortion is caused, in part, by self-phase modulation of the transmitted signal in the fiber optic link. The problem is particularly prevalent when data is transmitted at a wavelength other than the minimum dispersion wavelength of the fiber. Moreover, CSO distortion increases with the length of the fiber optic link and with the optical intensity modulation index of the primary modulator of the link. The phase modulator modulates an optical signal which is provided to the primary modulator in accordance with an optical phase modulation index k of an RF data signal to be transmitted. The phase modulator is effective with fiber optic links of varying lengths which carry amplitude-modulated vestigial sideband (AM-VSB) data signals such as cable television (CATV) signals.
REFERENCES:
patent: 5166821 (1992-11-01), Huber
patent: 5210633 (1993-05-01), Trisno
patent: 5327279 (1994-07-01), Farina et al.
patent: 5420868 (1995-05-01), Chaplysy et al.
patent: 5515199 (1996-05-01), Farina
patent: 5532857 (1996-07-01), Gertel et al.
patent: 5617239 (1997-04-01), Walker
Product Brief, AT&T Microelectronics, "m2410C/m2420C Dual-Output Lithium Niobate Modulator," Feb. 1995.
Data Sheet, United Technologies Photonics, "APE Dual Output Modulator for CATV Transmitters, 1320 and 1550 nm," Feb. 1995.
C. Desem, "Composite second order distortion due to self-phase modulation in externally modulated optical AM-SCM systems operating at 1550 nm," Eletronics Letters, Nov. 24, 1994, pp. 2055-2056.
M.R. Phillips et al., "Nonlinear Distortion Generated by Dispersive Transmission of Chirped Intensity-Modulated Signals," IEEE Photonics Technology Letters, vol. 3, No. 5, May 1991, pp. 481-483.
J.D. Farna, "New Method for Electro-Optic Linearization of External Modulators," IEEE/LEOS 1995 Digest of the LEOS Summer Topical Meetings, Aug. 7-11, 1995, p.81.
F. Koyama et al., "Frequency Chirping in External Modulators," IEEE Journal of Lightwave Technology, vol. 6, No. 1, Jan. 1988, pp. 87-93.
A. Djupsjobacka, "Residual Chirp in Integrated-Optic Modulators," IEEE Photonic Technology Letters, vol. 4, No. 1, Jan. 1992, pp. 41-43.
General Instrument Corporation of Delaware
Hoppin Ralph F.
Lipsitz Barry R.
Pascal Leslie
LandOfFree
Cancellation of distortion components in a fiber optic link with does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cancellation of distortion components in a fiber optic link with, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cancellation of distortion components in a fiber optic link with will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-212147