Abstract:In the paper, we review our work on heterogeneous III-V-on-silicon photonic components and circuits for applications in optical communication and sensing. We elaborate on the integration strategy and describe a broad range of devices realized on this platform covering a wavelength range from 850 nm to 3.85 μm.

Picosecond-pulse III-V-on-silicon mode-locked lasers based on linear and ring extended cavity geometries are presented. In passive modelocked operation a 12 kHz -3dB linewidth of the fundamental RF tone at 4.7 GHz is obtained for the linear cavity geometry and 16 kHz for the ring cavity geometry. Stabilization of the repetition rate of these devices using hybrid mode-locking is also demonstrated.

Abstract:A small footprint integrated Membrane InP Switch (MIPS) on Silicon-On-Insulator (SOI) is demonstrated for use in all-optical packet switching. The device consists of an optically pumped III-V membrane waveguide of only 100 nm thick, coupled to the underlying SOI waveguide circuit. Because of its limited thickness, the optical confinement in the active layers is maximized, allowing for high extinction ratio of over 30 dB when applying a low power optical pump signal, over the entire C-band. The switch has 400/1300 ps on/off switching times and no measurable pattern dependence or switching related power penalties for a bitrate up to 40 Gb/s, using a switching power of only 2 dBm.

Abstract:We present a five-channel wavelength division multiplexed modulator module that heterogeneously integrates a 200GHz channelspacing silicon arrayed-waveguide grating multiplexer and a 20Gbps electro -absorption modulator array, showing the potential for 100 Gbps transmission capacity on a 1.5x0.5 mm 2 footprint. ©2015 Optical Society of America IntroductionWavelength division multiplexing (WDM) modules are of key importance for realizing high aggregate bitrate optical networks and optical interconnects. WDM transmitters and receivers require low cost and high performance devices for maximal bandwidth usage and high energy-efficiency. For the key opto-electronic components in a WDM system, both silicon and III-V based devices are available. Potentially CMOS compatible, low-cost, monolithic silicon WDM modulator chips have been reported [1,2]. However, an optically broadband silicon-based modulator usually has a large footprint and requires a relatively high driving voltage and hence high power consumption for sufficient extinction ratio [3]. Alternatively, purely III-V WDM modulator chips have been demonstrated [4, 5]. Although they are more efficient than silicon modulators, the monolithic integration with passive wavelength division multiplexing devices, e.g. arrayed waveguide gratings (AWG) and etched diffractive gratings (EDG) is not straightforward. In order to overcome these issues, a hybrid silicon platform that combines the advantages of III-V based materials and silicon is being studied. III-V/Si hybrid active devices with excellent performance, such as hybrid silicon narrow linewidth lasers [6], high-speed modulators [7], and high-speed detectors [8] have already been demonstrated. The highest speed modulators on silicon were achieved by transferring a III-V epitaxy stack onto a SOI wafer to realize a 67GHz bandwidth traveling-wave hybrid silicon electro-absorption modulator (EAM) [7]. These hybrid devices can be integrated together to build up more complex on-chip photonic modules [9, 10] on silicon-based substrates, which shows its potential for high density, high performance WDM transmitters and receivers for optical communication networks and multi-CPU optical interconnects in the future.

An anti-colliding pulse-type III-V-on-silicon passively mode-locked laser is presented for the first time based on a III-V-on-silicon distributed Bragg reflector as outcoupling mirror implemented partially underneath the III-V saturable absorber. Passive mode-locking at 4.83 GHz repetition rate generating 3 ps pulses is demonstrated. The generated fundamental RF tone shows a 1.7 kHz 3 dB linewidth. Over 9 mW waveguide coupled output power is demonstrated. Mode-locked lasers provide a means of generating pure microwave signals that are essential in microwave photonic applications [1]. Passively mode-locked devices are of great interest since no RF signal needs to be provided to drive the laser: it generates a pulse train, the repetition rate of which is determined by the length of the laser cavity. Output power and the purity of the RF spectrum are of great importance in microwave photonic applications. In [2], an anti-colliding pulse mode-locked laser design is proposed, where the saturable absorber is implemented on the low-reflectivity outcoupling mirror of the laser cavity. The theoretical analysis of such a cavity under passive mode-locking points to higher output power, lower timing jitter, and better RF spectral purity compared to standard self-colliding pulse designs, where the saturable absorber is implemented next to the high-reflectivity mirror. Recently, this was also experimentally observed in III-V semiconductor devices [3]. In this Letter, we report the realization of an anti-colliding pulse-type mode-locked laser on a III-V-on-silicon platform for the first time. The implementation on this platform allows to easily fabricate distributed Bragg reflectors in the silicon device layer enabling the integration of these devices with other optical components. It also allows using low-loss silicon waveguide structures (both in terms of linear scattering losses as well as nonlinear two-photon absorption losses) to form the laser cavity, which positively affects the RF linewidth and optical output power. Moreover, the compatibility of the silicon photonics platform with high-volume manufacturing as well as the potential to co-integrate highspeed optical modulators and germanium photodetectors, make the integration of a mode-locked laser on a silicon photonics platform very attractive for microwave photonics. First demonstrations of low-phase-noise III-V-on-silicon mode-locked lasers were based on classical colliding ring cavity and self-colliding linear cavity arrangements. In this case, using stabilization of a linear cavity arrangement mode-locked laser through external optical feedback, 15 kHz 3 dB RF linewidth was obtained at 9.95 GHz repetition rate [4]. Recently, we also demonstrated ring cavity and linear cavity devices on our III-V-on-silicon platform, with a 12 kHz 3 dB RF linewidth, without stabilization using an external Fabry−Perot cavity [5]. The novel anti-colliding pulse-type III-V-on-silicon modelocked laser demonstrated in this work shows a 1.7 kHz 3 dB RF linewidth at 4.83 GHz, a substanti...