Long-wavelength vertical-cavity surface-emitting lasers (LW-VCSELs) with emission wavelength in the 1.3-µm region for intensity modulation (IM)/direct detection optical transmissions enable longer fiber reach compared to C-band VCSELs, thanks to the extremely low chromatic dispersion impact at that wavelength. A lot of effort has been recently dedicated to novel cavity designs in order to enhance LW-VCSELs' modulation bandwidth to allow higher data rates. Another approach to further improve VCSEL-based IM speed consists of making use of dedicated driver circuits implementing feedforward equalization (FFE). In this paper, we present a transmitter assembly incorporating a fourchannel 0.13-µm SiGe driver circuit wire-bonded to a novel dual 1.3-µm VCSEL array. The short-cavity indium phosphide buried tunnel junction VCSEL design minimizes both the photon lifetime and the device parasitic currents. The integrated driver circuit requires 2.5-V supply voltage only due to the implementation of a pseudobalanced regulator; it includes a two-tap asymmetric FFE, where magnitude, sign, relative delay, and pulse width distortion of the taps can be modified. Through the proposed transmitter, standard single-mode fiber reach of 20 and 4.5 km, respectively, for 28-and 40-Gb/s data rate has been demonstrated with stateof-the-art power consumption. Transmitter performance has been analyzed through pseudorandom bit sequences of both 2 7 −1 and 2 31 −1 length, and the additional benefit due to the use of the driver circuit has been discussed in detail. A final comparison with stateof-the-art VCSEL drivers is also includedt.

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Abstract-An integrated silicon-on-insulator microwave photonic phase shifter is demonstrated, based on an optical deinterleaver providing box-like transfer function and a reversebiased pn-junction waveguide optical phase shifter. The photonic integrated circuit is proved to precisely control the phase of microwave signals in a range of more than 400° with a fast reconfiguration time of 1 ns, with a broad bandwidth of more than 6 GHz around an RF carrier flexibly selectable between 10 and 16 GHz, and limited in-band RF power variations. Moreover, thanks to the periodic behavior of the deinterleaver, the device is demonstrated to correctly control the phase of signals in the mm-wave band (> 30 GHz) as well. The performance guaranteed by the proposed microwave phase shifter suggests its use in demanding applications as rapidly reconfiguring phased array antennas in future wireless communications systems.

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An integrated silicon-on-insulator microwave photonic phase shifter based on an optical deinterleaver and a reverse-biased pn-junction waveguide providing broadband phase shifts over more than 360° with an ultrafast reconfiguration time of 1 ns is demonstrated.

An innovative and effective architecture for lidar systems is presented and experimentally demonstrated. The proposed scheme can also be easily exploited for optical communications. In particular, the system includes an innovative lidar software-defined architecture based on optically coherent detection, overcoming current drawbacks of time of flight incoherent systems. The experiments demonstrate the ability to perform long range detection resorting to the waveform compression on the continuous wave approach, obtaining a range resolution of 15 cm with a sensitivity of -95  dBm. Beside the bulk implementation, the system has been also implemented in a photonic integrated circuit using complementary metal-oxide-semiconductor-compatible silicon on insulator technology with an extremely reduced footprint of 1.5  mm×3.5  mm. The testing of the integrated device confirms the effectiveness of this proof-of-concept realization.