Phase separation accompanied by further domain growth and coarsening is a phenomenon common to a broad variety of dynamical systems. In this connection, controlling such processes represents a relevant interdisciplinary problem. Using methods of numerical modelling, we demonstrate two approaches for the coarsening control in bistable systems based on the example of a spatially-extended model describing an optically-addressed spatial light modulator with two color illumination subject to optical feedback. The first method implies varying system parameters such that the system evolves as the pitchfork or saddle-node normal forms. The second method leverages noise whose intensity is used as an additional system parameter. Both, deterministic and stochastic schemes allow to control the direction and speed of the fronts separating spatial domains. The considered stochastic control represents a particular case of the noise-sustained front propagation in bistable systems and involves the properties of the optical system under study. In contrast, the proposed deterministic control technique can be applied to bistable systems of different nature.
Spatial light modulators (SLMs) are devices for modulating amplitude, phase or polarization of a light beam on demand. Such devices have been playing an indispensable inuence in many areas from our daily entertainments to scientific researches. In the past decades, the SLMs have been mainly operated in electrical addressing (EASLM) manner, wherein the writing images are created and loaded via conventional electronic interfaces. However, adoption of pixelated electrodes puts limits on both resolution and efficiency of the EASLMs. Here, we present an optically addressed SLM based on a nonlinear …
Nonlinear spatio-temporal systems are the basis for countless physical phenomena in such diverse fields as ecology, optics, electronics and neuroscience. The canonical approach to unify models originating from different fields is the normal form description, which determines the generic dynamical aspects and different bifurcation scenarios. Realizing different types of dynamical systems via one experimental platform that enables continuous transition between normal forms through tuning accessible system parameters is therefore highly relevant. Here, we show that a transmissive, optically-addre…
We report the design and characterization of high frequency, resonant acousto-optic modulators (AOM) in a MEMS foundry process. The doubly-resonant cavity design, with short ($L{\sim}10.5\, μm$) acoustic and optical cavity lengths, allows us to measure acousto-optic modulation at GHz frequencies with high modulation efficiency. In contrast to traditional AOMs, these devices rely on the perturbation induced by the displacement of cavity boundaries, which can be significantly enhanced in a suspended geometry. This platform can serve as the building block for fast 2D spatial light modulators (SLM…
High bandwidth, low voltage electro-optic modulators with high optical power handling capability are important for improving the performance of analog optical communications and RF photonic links. Here we designed and fabricated a thin-film lithium niobate (LN) Mach-Zehnder modulator (MZM) which can handle high optical power of 110 mW, while having 3-dB bandwidth greater than 110 GHz at 1550 nm. The design does not require etching of thin-film LN, and uses hybrid optical modes formed by bonding LN to planarized silicon photonic waveguide circuits. A high optical power handling capability in th…
In this article, we derive analytically the complex optical spectrum of a pulsed laser source obtained when a frequency comb generated by phase modulation is input into a synchronized intensity modulator. We then show how this knowledge of the spectrum may help to achieve unprecedented accuracy during the experimental spectrum correction step usually carried out with an optical spectrum processor. In numerical examples, for a given average power we present up to a 75 % increase in peak power and an enhancement of the extinction ratio by at least three orders of magnitude. This method also enab…
Topological photonic insulators pave the way toward efficient integrated photonic devices with minimized scattering losses. Optical properties of the majority of topological structures proposed to date are fixed by design such that no changes to their performance can be made once the device has been fabricated. However, tunability is important for many applications, including modulators, switches, or optical buffers. Therefore, we propose a straightforward way for the dynamic control of transmission in a silicon-based topological photonic crystal enabled by all-optical free-carrier excitation …
A fundamental challenge of the quantum revolution is to efficiently interface the quantum computing systems operating at cryogenic temperatures with room temperature electronics and media for high data-rate communication. Current approaches to control and readout of such cryogenic computing systems use electrical cables, which prevent scalability due to their large size, heat conduction, and limited bandwidth1. A more viable approach is to use optical fibers which allow high-capacity transmission and thermal isolation. A key component in implementing photonic datalinks is a cryogenic optical m…
Controlling the optical response of a medium through suitably tuned coherent electromagnetic fields is highly relevant in a number of potential applications, from all-optical modulators to optical storage devices. In particular, electromagnetically induced transparency (EIT) is an established phenomenon in which destructive quantum interference creates a transparency window over a narrow spectral range around an absorption line, which, in turn, allows to slow and ultimately stop light due to the anomalous refractive index dispersion. Here we report on the observation of a new form of either in…
This paper discusses free carrier generation by pulsed laser fields as a mechanism to switch the optical properties of semiconductor photonic crystals and bulk semiconductors on an ultrafast time scale. Requirements are set for the switching magnitude, the time-scale, the induced absorption as well as the spatial homogeneity, in particular for silicon at lambda= 1550 nm. Using a nonlinear absorption model, we calculate carrier depth profiles and define a homogeneity length l_hom. Homogeneity length contours are visualized in a plane spanned by the linear and two-photon absorption coefficients.…
Single-pixel imaging, originally developed in light optics, facilitates fast three-dimensional sample reconstruction, as well as probing with light wavelengths undetectable by conventional multi-pixel detectors. However, the spatial resolution of optics-based single-pixel microscopy is limited by diffraction to hundreds of nanometers. Here, we propose an implementation of single-pixel imaging relying on attainable modifications of currently available ultrafast electron microscopes in which optically-modulated electrons are used instead of photons to achieve sub-nanometer spatially- and tempora…
We show that the polarization state of coherent light propagating through an optically thick multiple-scattering medium, can be controlled by wavefront shaping, i.e. by controlling only the spatial phase of the incoming field with a spatial light modulator. Any polarization state of light at any spatial position behind the scattering medium can be attained with this technique. Thus, transforming the random medium to an arbitrary optical polarization component becomes possible.
Future quantum networks in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical quality factors up to 730,000 are achieved, corres…
We report the first experimental demonstration of prime number sieve via linear optics. The prime numbers distribution is encoded in the intensity zeros of the far field produced by a spatial light modulator hologram, which comprises a set of diffraction gratings whose periods correspond to all prime numbers below 149. To overcome the limited far field illumination window and the discretization error introduced by the SLM finite spatial resolution, we rely on additional diffraction gratings and sequential recordings of the far field. This strategy allows us to optically sieve all prime numbers…
Following how the electrical transistor revolutionized the field of electronics,the realization of an optical transistor in which the flow of light is controlled optically should open the long-sought era of optical computing and new data processing possibilities. However, such function requires photons to influence each other, an effect which is unnatural in free space. Here it is shown that a ferroelectric and photovoltaic crystal gated optically at the onset of its bandgap energy can act as a photonic transistor. The light-induced charge generation and distribution processes alter the intern…
Dynamic optical metasurfaces with ultrafast temporal response, i.e., spatiotemporal optical metasurfaces, provide attractive solutions and open fascinating perspectives for modern highly integrated optics and photonics. In this work, electro-optically controlled optical metasurfaces operating in reflection and utilizing resonant waveguide mode excitation are demonstrated from the viewpoint of free-space propagating light modulation. The modulation of reflected light power with superior characteristics in comparison with prior research is achieved by identifying a suitable low-loss waveguide mo…
We present a technique for generating light in an arbitrary polarization state. The technique is based on interference of two orthogonally polarized light beams, whose amplitudes and phases are controlled with a Mach-Zehnder inteferometer with acousto-optic modulators (AOMs) placed in each arm. We demonstrate that via control over amplitudes, phases, and frequencies of acoustic waves driving the AOMs, any polarization state can be synthesized. In particular, we demonstrate generation of linearly polarized light, whose polarization plane continuously rotates at a rate from 1~kHz to 1~MHz. Such …
Optically-Induced Modulation and Programming of Diamond Photonic Cavities
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL)（洛桑联邦理工学院物理研究所）；Center of Quantum Science and Engineering, Swiss Federal Institute of Technology Lausanne (EPFL)（洛桑联邦理工学院量子科学与工程中心）；Photonics Research Group, Department of Information Technology (INTEC), Ghent University - IMEC（根特大学信息技朮系光子研究组（与IMEC联合））；University of Stuttgart（斯图加特大学）
The use of individual multimode optical fibers in endoscopy applications has the potential to provide highly miniaturized and noninvasive probes for microscopy and optical micromanipulation. A few different strategies have been proposed recently, but they all suffer from intrinsically low resolution related to the low numerical aperture of multimode fibers. Here, we show that two-photon polymerization allows for direct fabrication of micro-optics components on the fiber end, resulting in an increase of the numerical aperture to a value that is close to 1. Coupling light into the fiber through …
A liquid crystal optical device made of an optically anisotropic heterostructure is considered. The device consists of a cholesteric liquid crystal (CLC) layer sandwiched by two phase-shifting anisotropic layers of a nematic liquid crystal (NLC). In this structure each of the NLC layers is a quarterwave plate. The problem is solved both by Ambartsumian method of layer addition and Muller matrix method. The peculiarities of reflection spectra, eigen polarizations, rotation of polarization plane and polarization ellipticity are studied. It is shown that this device can work as a light modulator …
To manipulate cold atoms in spatially constrained quantum engineering platforms, we developed a lensless optical system with a $\sim$1 $μ$m resolution and a transverse size of only 225 $μ$m. We use a multimode optical fiber with a high numerical aperture, which directly guides light inside the ultra-high-vacuum system. Spatial light modulators allow us to generate control beams at the in-vacuum fiber end by digital optical phase conjugation. As a demonstration, we use this system to optically transport cold atoms towards the in-vacuum fiber end, to load them in optical microtraps and to re-coo…
Optical Implementation of Equilibrium Propagation Using Spatial Photonic Ising Machines
Laboratoire d’Information Quantique, Université Libre de Bruxelles (ULB)（量子信息实验室，布鲁塞尔自由大学）；Dipartimento di Fisica, Sapienza Università di Roma（物理学系，萨皮恩扎罗马大学）
The dielectric permittivity of a material encapsulates the essential physics of light-matter interaction into the material's local response to optical excitation. Dynamic, photo-induced modulation of the permittivity can enable an unprecedented level of control over the phase, amplitude, and polarization of light. Therefore, the detailed dynamic characterization of technology-relevant materials with substantially tunable optical properties and fast response times is a crucial step in the realization of tunable optical devices. This work reports on the extraordinarily large permittivity changes…
