We investigate the coexistence of clock synchronization protocols with quantum signals propagating in a common optical single-mode fiber channel. By measuring optical forward and backward scattering noise in a range from 1510 nm to 1620 nm we demonstrate a potential for up to 100 quantum channels each with 100 GHz bandwidth coexisting with the classical synchronization signals using off-the-shelf optical components. Both “White Rabbit'' and a pulsed laser-based synchronization were characterized and compared.
Optical time-domain reflectometry (OTDR) is one of the most used techniques for nondestructive characterization of optical fiber links. Although conventional OTDR exhibits good performance in classical network applications, photoncounting OTDR (ν-OTDR) offers a promising way for in-situ optical channel characterization of quantum network fibers where single-photon detectors are present. ν-OTDR has been demonstrated at the telecommunication wavelengths of 1310 and 1550 nm. Here, we present our hyperspectral ν-OTDR measurement covering a wavelength range from 1150 nm to 1800 nm. The results show low attenuation in SMF-28 fiber between 1150 nm and 1700 nm of less than 0.5 dB/km. However, we show that connector loss can worsen significantly for wavelengths greater than 1550 nm.
Entangled photon sources are fundamental building blocks for quantum communication and quantum networks. Recently, silicon carbide emerged as a promising material for integrated quantum devices since it is CMOS compatible with favorable mechanical, electrical and photonic properties. In this work, we report the progress on the entangled photon pair generation at the telecom wavelength (1550 nm), which is achieved by implementing the spontaneous four-wave mixing process in a compact silicon carbide microring resonator. We will present the design principle, experimental set-up, and results of this work.
A quantum network will consist of many physically separated nodes connected by quantum communication channels that distribute entanglement between them. Such nodes will require mechanisms for the generation, routing, and measurement of quantum states to fulfill various quantum communication protocols between any two quantum nodes. An aim of our quantum network metrology program is to develop portable, low-cost, robust, and reliable tools that can be deployed anywhere into a quantum network testbed for these purposes. The prototype source and receiver systems described here will serve as benchmarking devices for the implementation of quantum network metrology in real-life testbeds and are, by-design, integrated into a 19” rack to allow for the easy deployment into anywhere with standard networking infrastructure. Measurements performed using this toolset have shown a fidelity of more than 0.98 with a polarization entanglement visibility of 0.97.
Azobenzene-containing polymers have attracted much attention as photo-responsive materials owing to potential applications in optical data storage and holographic recording. In holography, azobenzene compounds doped in a polymer matrix (guest- host polymer film) or chemically attached to the polymer (co-polymer) are among the most widely used materials. Azo-polymers exhibit differing behaviors when exposed to a pattern resulting from the interference of two coherent beams. In the guest-host system, the recorded grating corresponds to a contrast of refractive index between the dark and bright areas of the film, and in the co-polymer, interference patterns lead to surface height modulation; i.e. surface relief gratings (SRGs). The latter is due to photo-induced mass movement of the polymer from bright to the dark area of the interference pattern in the direction of the intensity gradient, and the photoisomerization force is at the origin of the formation of the gratings. In this paper, we give an overview of our experiments on holographic recording in both guest host and co-polymers systems; e.g. doped and covalently attached polymers, and based on the theory of photo-induced vectorial mobility of matter, we discuss the results obtained for the co-polymer system.
The investigation of light-matter interaction has had growing interest in the field of photonics. In particular, metalinsulator-metal (MIM) sensors are of interest owing to their high sensitivity compared to conventional sensor made by a single metal layer. The high resolution and low concentrations detection is a result of the sharp resonance of the surface plasmon polariton waveguide hybrid mode at the Au/water interface supported by MIM structures. In this context, we have implemented experiments and theoretical simulations to estimate the enhancement of the sensitivity of metal-insulatormetal sensors. By changing the refractive index of an aqueous solution of glucose, we found that the use of a metalinsulator-metal stack improves the figure of merit of the sensor 7.5 times compared to that of a conventional surface plasmon resonance sensor.
Two photon polymerization, based on two-photon absorption, is a powerful and potential technique to fabricate 3D micro/nanostructures with submicrometric resolution. We use a photopolymerizable resin based on methyl methacrylate monomers as a photosensitive medium, in which the polymerization is triggered by the nonlinear optical effect. Nonlinear effect photoreaction occurs only in a submicrometric volume, voxel, much smaller than the cube of the wavelength, λ3. By using a femtosecond laser, 780 nm wavelength, we investigate the effect of different parameters on the resolution of our custom made micro/nanofabrication set up. The fabrication accuracy and the resolution of 3D micro/nanostructures depend on the accuracy of the focal spot position in z-direction, in the glass substrate-resin interface. We control the focal spot position by using ascending scan process meaning the focus spot level. Employing the proposed process, the lateral resolution of individual voxels, is improved almost to 94 nm. The resolution of two photon absorption polymerized voxels is studied as a function of focus spot level, laser power and single-shot irradiation time. Finally, we show 3D microstructures and a micro-device, which present great potential for future applications.
Over the past two decades, surface relief gratings have attracted much interest owing to their potential applications in optical data storage and optical communication and holography. Azobenzene-containing polymer films show an interesting behavior under irradiation with light interference patterns. The inhomogeneous irradiation; e.g. due to the interference pattern, of the azo-polymer film causes mass movement of the polymer from bright to dark area, and the mechanism underlying the formation of SRG finds its origin in the photoisomerization force. The latter is due to an inhomogeneous light irradiation which causes photoisomerization and increases the polymer mobility in the bright area, and owing to the intensity gradient, due to light interference, the photoisomerization force moves the polymer from the bright area into the dark. In this paper we discuss our experiments of holographic recording in films of Poly (Disperse Red 1 methacrylate); e.g. azo-polymer films, and the recorded surface relief gratings were investigated by using atomic force microscopy. The dependence of the polarization state and intensity of the writing beams was studied, and the diffraction efficiency was monitored in real time during the process of inscription. A brief description of the photoisomerization force is given.
We present experimental evidence of the generation of narrow Fano line shapes in planar multilayer
structures. The Fano line shape originates from coupling between a high loss surface plasmon
polariton mode with a low loss planar waveguide mode. The line shape is shown to depend strongly
on the structural parameters that govern the position of the waveguide mode and the coupling
strength, and to be in good agreement with results of electromagnetic calculations.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.