Transparent Perfect Mirror

A mirror that reflects light fully and yet is transparent appears paradoxical. Current so-called transparent or "one-way" mirrors are not perfectly reflective and thus can be distinguished from a standard mirror. Constructing a transparent "perfect" mirror has profound implications for security, privacy, and camouflage. However, such a hypothetical device cannot be implemented in a passive structure. We demonstrate here a transparent perfect mirror in a non-Hermitian configuration: an active optical cavity where a certain prelasing gain extinguishes Poynting's vector at the device entrance. At this threshold, all vestiges of the cavity's structural resonances are eliminated and the device presents spectrally flat unity-reflectivity, thus, becoming indistinguishable from a perfect mirror when probed optically across the gain bandwidth. Nevertheless, the device is rendered transparent by virtue of persisting amplified transmission resonances. We confirm these predictions in two photonic realizations: a compact integrated active waveguide and a macroscopic all-optical-fiber system.Comment: The paper is highlighted in Nature Photonics: http://www.nature.com/nphoton/journal/v11/n6/full/nphoton.2017.90.html The supplementary data is available in: http://pubs.acs.org/doi/suppl/10.1021/acsphotonics.7b0005

On-Chip Demonstration Of A Transparent Perfect Mirror

We experimentally demonstrate an active cavity exhibiting 100% spectrally flat reflection with no vestiges of structural resonances while still transmitting light across the gain bandwidth. This non-Hermitian structure is realized in an indium-phosphide platform

Transparent Perfect Mirror

A mirror that reflects light fully and yet is transparent appears paradoxical. Current so-called transparent or “one-way” mirrors are not perfectly reflective and thus can be distinguished from a standard mirror. Constructing a transparent “perfect” mirror has profound implications for security, privacy, and camouflage. However, such a hypothetical device cannot be implemented in a passive structure. We demonstrate here a transparent perfect mirror in a non-Hermitian configuration: an active optical cavity where a certain prelasing gain extinguishes Poynting’s vector at the device entrance. At this threshold, all vestiges of the cavity’s structural resonances are eliminated and the device presents spectrally flat unity-reflectivity, thus, becoming indistinguishable from a perfect mirror when probed optically across the gain bandwidth. Nevertheless, the device is rendered transparent by virtue of persisting amplified transmission resonances. We confirm these predictions in two photonic realizations: a compact integrated active waveguide and a macroscopic all-optical-fiber system

On-Chip Demonstration Of A Transparent Perfect Mirror

We experimentally demonstrate an active cavity exhibiting 100% spectrally flat reflection with no vestiges of structural resonances while still transmitting light across the gain bandwidth. This non-Hermitian structure is realized in an indium-phosphide platform

Spectral Response Of An Active Photonic Cavity At The Poynting\u27S Threshold

We establish a sub-lasing critical gain in a 1inear cavity at which Poynting\u27s vector vanishes at the cavity entrance. We show the cavity reflection spectrum becomes flat at this critical gain, and the device becomes indistinguishable from a perfect mirror - that nevertheless transmits light

Integrating III-V, Si, and polymer waveguides for optical interconnects: RAPIDO

We present a vision for the hybrid integration of advanced transceivers at 1.3 μm wavelength, and the progress done towards this vision in the EU-funded RAPIDO project. The final goal of the project is to make five demonstrators that show the feasibility of the proposed concepts to make optical interconnects and packet-switched optical networks that are scalable to Pb/s systems in data centers and high performance computing. Simplest transceivers are to be made by combining directly modulated InP VCSELs with 12 μm SOI multiplexers to launch, for example, 200 Gbps data into a single polymer waveguide with 4 channels to connect processors on a single line card. For more advanced transceivers we develop novel dilute nitride amplifiers and modulators that are expected to be more power-efficient and temperatureinsensitive than InP devices. These edge-emitting III-V chips are flip-chip bonded on 3 μm SOI chips that also have polarization and temperature independent multiplexers and low-loss coupling to the 12 μm SOI interposers, enabling to launch up to 640 Gbps data into a standard single mode (SM) fiber. In this paper we present a number of experimental results, including low-loss multiplexers on SOI, zero-birefringence Si waveguides, micron-scale mirrors and bends with 0.1 dB loss, direct modulation of VCSELs up to 40 Gbps, ±0.25μm length control for dilute nitride SOA, strong band edge shifts in dilute nitride EAMs and SM polymer waveguides with 0.4 dB/cm loss