Co-Design and Demonstration of a 25-Gb/s Silicon-Photonic Mach–Zehnder Modulator With a CMOS-Based High-Swing Driver

Taking silicon photonics modulators to a higher performance level: state-of-the-art and a review of new technologies

“…High-speed transceivers for short-reach (few cm to few tens of km) and long-haul optical communication links require high-performance modulators in their transmitter optical subassembly. [1][2][3] The key performance parameters for an efficient modulator are (a) high modulation efficiency [4][5][6][7][8][9] in amplitude or phase by a drive signal that is compliant with the complementary metal-oxide-semiconductor (CMOS) circuitry 5,6 [for phase modulators, the modulation efficiency is defined as the product of voltage V π applied to the phase shifter to achieve π phase shift and the length L of the phase shifter-a smaller V π • L represents higher modulation efficiency; for amplitude modulation, the ratio of extinction ratio (ER) to an applied voltage for a given length of the modulator represents the modulation efficiency and large values are desired]; (b) low insertion loss (IL), [10][11][12][13] both low loss in the active and passive parts of the modulator; (c) tens of gigabits per second (Gb/s) [14][15][16][17] modulation speed to support the future capacity demands of the optical communication networks; (d) energy consumption to be as low as a few tens of fJ/bit; [18][19][20] (e) large ER-typically ∼4 dB for ∼2 km transmission links and ∼8 dB for tens of km long transmission linksto ensure high optical signal-to-noise ratio for maintaining a low bit error rate; [21][22][23][24][25] (f) low chirp [26][27][28] to realize higher-order modulation schemes [27][28][29] and to enhance dispersion tolerance of transmission links; 26,30 and (g) compact size…”

“…The electrical driving of the modulator comprises an electrode configuration and the driving scheme (such as single-ended drive with dual-arm push-pull, differential drive with dualarm push-pull, differential drive with dual-arm push-pull with shared drive, or dual-differential drive with dual-arm push-pull) to feed the electrodes. 25 Generally, the length of the phase shifter determines the electrode configuration. 209 Modulators with a short phase shifter length (phase shifter length <λ RF ∕10) 2,25 use lumped electrodes.…”

“…113,114 The traveling wave (TW) is the most common driving scheme for carrier depletion plasma dispersion MZMs. 2,4,25,210,212 In this scheme, a single driver drives the entire electrode of the phase shifter. 25,212 The TW electrode typically comprises a coplanar waveguide transmission line.…”

“…2,4,25,210,212 In this scheme, a single driver drives the entire electrode of the phase shifter. 25,212 The TW electrode typically comprises a coplanar waveguide transmission line. It terminates with a resistive impedance matched to the wave impedance of the electrode.…”

Electrically packaged silicon-organic hybrid (SOH) I/Q-modulator for 64 GBd operation

“…Moreover, flip-chip bonding of photonic devices often requires dedicated processes that need to be adapted to specific optical components in terms of thermal budget or with respect to the deployed flux chemicals [15,21]. In contrast to flip-chip bonding, accessing high-density PIC by metallic wire bonds leaves the top surface of the chip free and thus offers high flexibility with respect to optical packaging [22][23][24][25][26][27][28][29][30], exploiting, e.g., highly efficient SiP grating couplers [31], photonic wire bonds [32], or facet-attached micro-lenses [33]. However, published signaling demonstrations using SiP modulators accessed by metal wire bonds have so far been limited to symbol rates of 28 GBd.…”