Reconfigurable photonic integrated circuits(PICs)can implement arbitrary operations and signal processing functionalities directly in the optical domain.Run-time configuration of these circuits requires an electronic ...Reconfigurable photonic integrated circuits(PICs)can implement arbitrary operations and signal processing functionalities directly in the optical domain.Run-time configuration of these circuits requires an electronic control layer to adjust the working point of their building elements and compensate for thermal drifts or degradations of the input signal.As the advancement of photonic foundries enables the fabrication of chips of increasing complexity,developing scalable electronic controllers becomes crucial for the operation of complex PICs.In this paper,we present an electronic application-specific integrated circuit(ASIC)designed for reconfiguration of PICs featuring numerous tunable elements.Each channel of the ASIC controller independently addresses one optical component of the PIC,and multiple parallel local feedback loops are operated to achieve full control.The proposed design is validated through real-time reconfiguration of a 16-channel silicon photonics adaptive universal beam coupler.Results demonstrate automatic coupling of an arbitrary input beam to a single-mode waveguide,dynamic compensation of beam wavefront distortions and successful transmission of a 50 Gbit/s signal through an optical free-space link.The low power consumption and compactness of the electronic chip provide a scalable paradigm that can be seamlessly extended to larger photonic architectures.展开更多
Propagation of light beams through scattering or multimode systems may lead to the randomization of the spatial coherence of the light.Although information is not lost,its recovery requires a coherent interferometric ...Propagation of light beams through scattering or multimode systems may lead to the randomization of the spatial coherence of the light.Although information is not lost,its recovery requires a coherent interferometric reconstruction of the original signals,which have been scrambled into the modes of the scattering system.Here we show that we can automatically unscramble optical beams that have been arbitrarily mixed in a multimode waveguide,undoing the scattering and mixing between the spatial modes through a mesh of silicon photonics tuneable beam splitters.Transparent light detectors integrated in a photonic chip are used to directly monitor the evolution of each mode along the mesh,allowing sequential tuning and adaptive individual feedback control of each beam splitter.The entire mesh self-configures automatically through a progressive tuning algorithm and resets itself after significantly perturbing the mixing,without turning off the beams.We demonstrate information recovery by the simultaneous unscrambling,sorting and tracking of four mixed modes,with residual cross-talk of−20 dB between the beams.Circuit partitioning assisted by transparent detectors enables scalability to meshes with a higher port count and to a higher number of modes without a proportionate increase in the control complexity.The principle of self-configuring and self-resetting in optical systems should be applicable in a wide range of optical applications.展开更多
Free-space optics naturally offers multiple-channel communications and sensing exploitable in many applications. The different optical beams will, however, generally be overlapping at the receiver, and, especially wit...Free-space optics naturally offers multiple-channel communications and sensing exploitable in many applications. The different optical beams will, however, generally be overlapping at the receiver, and, especially with atmospheric turbulence or other scattering or aberrations, the arriving beam shapes may not even be known in advance. We show that such beams can be still separated in the optical domain, and simultaneously detected with negligible cross-talk, even if they share the same wavelength and polarization, and even with unknown arriving beam shapes. The kernel of the adaptive multibeam receiver presented in this work is a programmable integrated photonic processor that is coupled to free-space beams through a two-dimensional array of optical antennas. We demonstrate separation of beam pairs arriving from different directions, with overlapping spatial modes in the same direction, and even with mixing between the beams deliberately added in the path. With the circuit’s optical bandwidth of more than 40 nm, this approach offers an enabling technology for the evolution of FSO from single-beam to multibeam space-division multiplexed systems in a perturbed environment, which has been a game-changing transition in fiber-optic systems.展开更多
In technologies operating at light wavelengths for wireless communication,sensor networks,positioning,and ranging,a dynamic coherent control and manipulation of light fields is an enabling element for properly generat...In technologies operating at light wavelengths for wireless communication,sensor networks,positioning,and ranging,a dynamic coherent control and manipulation of light fields is an enabling element for properly generating and correctly receiving free-space optical(FSO)beams even in the presence of unpredictable objects and turbulence in the light path.In this work,we use a programmable mesh of Mach-Zehnder(MZI)interferometers to automatically control the complex field radiated and captured by an array of optical antennas.The implementation of local feedback control loops in each MZI stage,without global multivariable optimization techniques,enables an unlimited scalability.Several functionalities are demonstrated,including the generation of perfectly shaped beams with nonperfect optical antennas,the imaging of a desired field pattern through an obstacle or a diffusive medium,and the identification of an unknown obstacle inserted in the FSO path.Compared to conventional devices used for the manipulation of FSO beams,such as spatial light modulators,our programmable device can self-configure through automated control strategies and can be integrated with other functionalities implemented onto the same photonic chip.展开更多
基金supported by the Italian National Recovery and Resilience Plan(NRRP)of Nex tGeneration EU,partnership on“Telecommunications of the Future”(Program“RESTART”,Structural Project“Rigoletto,”and Focused Project“HePIC”)under Grant PE00000001.
文摘Reconfigurable photonic integrated circuits(PICs)can implement arbitrary operations and signal processing functionalities directly in the optical domain.Run-time configuration of these circuits requires an electronic control layer to adjust the working point of their building elements and compensate for thermal drifts or degradations of the input signal.As the advancement of photonic foundries enables the fabrication of chips of increasing complexity,developing scalable electronic controllers becomes crucial for the operation of complex PICs.In this paper,we present an electronic application-specific integrated circuit(ASIC)designed for reconfiguration of PICs featuring numerous tunable elements.Each channel of the ASIC controller independently addresses one optical component of the PIC,and multiple parallel local feedback loops are operated to achieve full control.The proposed design is validated through real-time reconfiguration of a 16-channel silicon photonics adaptive universal beam coupler.Results demonstrate automatic coupling of an arbitrary input beam to a single-mode waveguide,dynamic compensation of beam wavefront distortions and successful transmission of a 50 Gbit/s signal through an optical free-space link.The low power consumption and compactness of the electronic chip provide a scalable paradigm that can be seamlessly extended to larger photonic architectures.
基金the European Union's Seventh FP7 Programme(Grant agreement No.323734,BBOI)the European Union’s H2020 Programme(Grant No.688172,STREAMS)+1 种基金Fondazione Cariplo(Grant No.2016-0881,ACTIO)by Multidisciplinary University Research Initiative grant(Air Force Office of Scientific Research,FA9550-12-1-0024)。
文摘Propagation of light beams through scattering or multimode systems may lead to the randomization of the spatial coherence of the light.Although information is not lost,its recovery requires a coherent interferometric reconstruction of the original signals,which have been scrambled into the modes of the scattering system.Here we show that we can automatically unscramble optical beams that have been arbitrarily mixed in a multimode waveguide,undoing the scattering and mixing between the spatial modes through a mesh of silicon photonics tuneable beam splitters.Transparent light detectors integrated in a photonic chip are used to directly monitor the evolution of each mode along the mesh,allowing sequential tuning and adaptive individual feedback control of each beam splitter.The entire mesh self-configures automatically through a progressive tuning algorithm and resets itself after significantly perturbing the mixing,without turning off the beams.We demonstrate information recovery by the simultaneous unscrambling,sorting and tracking of four mixed modes,with residual cross-talk of−20 dB between the beams.Circuit partitioning assisted by transparent detectors enables scalability to meshes with a higher port count and to a higher number of modes without a proportionate increase in the control complexity.The principle of self-configuring and self-resetting in optical systems should be applicable in a wide range of optical applications.
基金the European Commission,Horizon 2020 Programme(SuperPixels,grant no.829116)by the Air Force Office of Scientific Research(AFOSR,grant no.FA9550-17-1-0002).
文摘Free-space optics naturally offers multiple-channel communications and sensing exploitable in many applications. The different optical beams will, however, generally be overlapping at the receiver, and, especially with atmospheric turbulence or other scattering or aberrations, the arriving beam shapes may not even be known in advance. We show that such beams can be still separated in the optical domain, and simultaneously detected with negligible cross-talk, even if they share the same wavelength and polarization, and even with unknown arriving beam shapes. The kernel of the adaptive multibeam receiver presented in this work is a programmable integrated photonic processor that is coupled to free-space beams through a two-dimensional array of optical antennas. We demonstrate separation of beam pairs arriving from different directions, with overlapping spatial modes in the same direction, and even with mixing between the beams deliberately added in the path. With the circuit’s optical bandwidth of more than 40 nm, this approach offers an enabling technology for the evolution of FSO from single-beam to multibeam space-division multiplexed systems in a perturbed environment, which has been a game-changing transition in fiber-optic systems.
基金H2020 Future and Emerging Technologies(829116)Air Force Office of Scientific Research(FA9550-17-1-000)。
文摘In technologies operating at light wavelengths for wireless communication,sensor networks,positioning,and ranging,a dynamic coherent control and manipulation of light fields is an enabling element for properly generating and correctly receiving free-space optical(FSO)beams even in the presence of unpredictable objects and turbulence in the light path.In this work,we use a programmable mesh of Mach-Zehnder(MZI)interferometers to automatically control the complex field radiated and captured by an array of optical antennas.The implementation of local feedback control loops in each MZI stage,without global multivariable optimization techniques,enables an unlimited scalability.Several functionalities are demonstrated,including the generation of perfectly shaped beams with nonperfect optical antennas,the imaging of a desired field pattern through an obstacle or a diffusive medium,and the identification of an unknown obstacle inserted in the FSO path.Compared to conventional devices used for the manipulation of FSO beams,such as spatial light modulators,our programmable device can self-configure through automated control strategies and can be integrated with other functionalities implemented onto the same photonic chip.
