论文信息 - Spread spectrum frequency response of coded phase reversal traveling wave modulators

Spread spectrum frequency response of coded phase reversal traveling wave modulators

Application of aperiodic phase reversals to the electrode pattern of a Mach-Zehnder traveling wave modulator according to suitable pseudorandom sequences considerably improves the high-frequency response for fixed drive voltage. Simulations for a family of devices based on the Barker codes are presented, in the presence of frequency dependent microwave losses and impedance mismatch, using a new theorem relating the modulation transfer function to the Laplace transform of the electrode pattern evaluated on a parabolic contour in the s -plane. Projecting from our recent experimental results on 4 and 5 bit Barker codes, at 1.3-μm wavelengths, a 2-cm-long 13-bit Barker code device fabricated in LiNbO 3 will exhibit 5-dB optical modulation bandwidth in excess of 50 GHz with a half-wave voltage less than 8 V.

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