Vincent J. Urick
United States Naval Research Laboratory
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Publication
Featured researches published by Vincent J. Urick.
Journal of Lightwave Technology | 2011
Vincent J. Urick; Frank Bucholtz; Jason D. McKinney; Preetpaul S. Devgan; Anthony L. Campillo; James L. Dexter; Keith J. Williams
A paper on long-haul analog photonics is presented using theory and experimental results. Various analog fiber-optic modulation formats are reviewed, including intensity modulation with direct detection, phase modulation with interferometric demodulation, and suppressed-carried techniques. Modulation linearization methods are reviewed. The limitations of and requirements for photodiode detectors are described.
IEEE Transactions on Microwave Theory and Techniques | 2007
Vincent J. Urick; Frank Bucholtz; Preetpaul S. Devgan; Jason D. McKinney; Keith J. Williams
We analyze the performance of analog-photonic links employing phase modulation with interferometric demodulation and compare it to intensity-modulation direct-detection links. We derive expressions for RF gain, RF noise figure, compression dynamic range, and spurious-free dynamic range for both architectures. We demonstrate theoretically and experimentally that phase-modulated links can outperform intensity-modulated links over substantial frequency ranges.
IEEE Photonics Technology Letters | 2004
Vincent J. Urick; Joe X. Qiu; Frank Bucholtz
Transmission of microwave quadrature amplitude modulation over an all-Raman 105-km fiber-optic link is demonstrated. The link employs optical phase modulation and single-port interferometric demodulation to deliver up to 6 Gb/s in a single channel.
IEEE Transactions on Microwave Theory and Techniques | 2006
Vincent J. Urick; Matthew S. Rogge; Frank Bucholtz; Keith J. Williams
We present the tradeoffs of employing highly compressed erbium-doped fiber amplifiers (EDFAs) in analog microwave photonic links. We employ the newly developed concept of noise penalty and introduce the concept of generalized relative intensity noise to facilitate system design. Theoretical and experimental results demonstrate that a highly compressed EDFA: 1) can achieve near shot-noise-limited performance, even with large optical noise figure and 2) can simultaneously increase the spurious-free dynamic range, increase the compression dynamic range, increase the analog gain, and decrease the analog noise figure, as compared to an unamplified link with identical components.
IEEE Transactions on Microwave Theory and Techniques | 2006
Vincent J. Urick; Matthew S. Rogge; Patrick F. Knapp; Lee Swingen; Frank Bucholtz
We analyze the performance of a custom wide-band predistortion linearizer designed to operate in conjunction with an externally modulated analog photonic link. In addition, we propose an extended spurious-free dynamic-range (SFDR) specification for analog photonic links employing linearization techniques. The benefits of predistortion linearization for analog fiber links limited by optical amplifier noise are demonstrated and a 6-12-GHz 20-km analog link is shown to achieve a SFDR of 108.4 dB/spl middot/Hz/sup 2/3/, a 6-dB increase relative to the uncompensated link.
Journal of Lightwave Technology | 2008
Bryan M. Haas; Vincent J. Urick; Jason D. McKinney; Thomas E. Murphy
We demonstrate a new technique for improving the linearity of a microwave photonic signal transmission link. The method employs a single conventional lithium-niobate phase modulator at the transmitter, with two different C-band optical wavelengths that are polarized along orthogonal axes of the modulator. The spurious-free dynamic range is shown to improve by 15 dB compared to a single-wavelength unlinearized system. Unlike earlier schemes that require continuous control and adjustment at the transmitter in order to maintain linearity, the new method enables all of the linearization to be controlled at the receiver end.
Journal of Lightwave Technology | 2009
Vincent J. Urick; Modesto E. Godinez; Preetpaul S. Devgan; Jason D. McKinney; Frank Bucholtz
In this paper, a complete analysis of an analog fiber-optic link employing a low-biased Mach-Zehnder modulator followed by optical amplification with an erbium-doped fiber amplifier is presented. The expressions for RF gain, RF noise figure, second- and third-order intercept points, and spurious-free dynamic range are derived. Experimental data are employed to support the analytical results, and the optimal bias points for the metrics are demonstrated.
IEEE Photonics Technology Letters | 2005
Vincent J. Urick; Frank Bucholtz
We present the design and demonstration of a receiver that compensates for arbitrary net chromatic dispersion in an analog fiber-optic link for double-sideband amplitude and phase modulation formats.
Journal of Lightwave Technology | 2009
Preetpaul S. Devgan; Vincent J. Urick; John F. Diehl; Keith J. Williams
We have investigated the improvement in the phase noise of a 10 GHz optoelectronic oscillator using all-photonic gain as compared to using an electronic amplifier in the cavity. The optoelectronic oscillator achieves the necessary RF gain for oscillation by using the carrier-suppression technique of a low-biased Mach-Zehnder modulator (MZM) followed by optical amplification. The measured RF gain due to this all-photonic technique is as high as 15 dB and matches well with theoretical predictions. The phase noise of the generated 10 GHz signal is at least 10 dB lower than the signal from the same oscillator using an electronic amplifier. The improvement in the phase noise is due to the lower RF noise figure of the all-photonic gain process as compared to the electronic amplifier configuration.
Proceedings of SPIE | 2012
Vincent J. Urick; John F. Diehl; Meredith N. Draa; Jason D. McKinney; Keith J. Williams
High-performance analog photonic links are discussed and the prevalent modulation formats are highlighted. Because of its multi-octave and millimeter-wave potential, special attention is given to intensity modulation with direct detection (IMDD) employing an external Mach-Zehnder modulator (MZM). The theory for IMDD is reviewed and some experimental results are discussed. Two limiting factors in multi-octave IMDD implementations are quantified. The MZM bias requirements in order to remain third-order limited are shown to be very stringent in high-performance links. Photodiode nonlinearities, perhaps the most inhibiting factor in present-day wideband analog photonics, are cast in terms of output intercept points and tied to the IMDD link performance.