An exact analytical expression of the signal-to-noise ratio (SNR) for an intersatellite microwave photonics link with an optical preamplifier is derived considering the signal fade caused by the pointing errors of the transceiver, and an optimized model for laser output power and direct current (DC) bias phase shift of the Mach–Zehnder modulator is established. It is shown that, given the desired SNR and the root mean square (rms) random pointing jitter, an optimal DC bias phase shift exists that minimizes laser output power. The effects of the optical preamplifier parameters on the minimum laser output power and optimal DC bias phase shift are also examined. Numerical results show that the preamplifier noise figure determines the minimum laser output power needed to achieve the desired SNR but affects the optimal DC bias phase shift little. For a SNR of 20 dB, doubling the preamplifier noise figure results in a 6.36 dB increase in minimum laser output power for rms pointing jitter of 0.4 μrad.
© 2012 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: May 7, 2012
Revised Manuscript: October 14, 2012
Manuscript Accepted: October 15, 2012
Published: November 9, 2012
Zihang Zhu, Shanghong Zhao, Yongjun Li, Xingchun Chu, Rui Hou, Xiang Wang, and Guhao Zhao, "Optimization of an analog intersatellite microwave photonics link with an optical preamplifier," J. Opt. Soc. Am. A 29, 2525-2531 (2012)