Metasurfaces are planar structures that locally modify the polarization, phase and amplitude of light in reflection or transmission, thus enabling lithographically patterned flat optical components with functionalities controlled by design. Transmissive metasurfaces are especially important, as most optical systems used in practice operate in transmission. Several types of transmissive metasurface have been realized, but with either low transmission efficiencies or limited control over polarization and phase. Here, we show a metasurface platform based on high-contrast dielectric elliptical nanoposts that provides complete control of polarization and phase with subwavelength spatial resolution and an experimentally measured efficiency ranging from 72% to 97%, depending on the exact design. Such complete control enables the realization of most free-space transmissive optical elements such as lenses, phase plates, wave plates, polarizers, beamsplitters, as well as polarization-switchable phase holograms and arbitrary vector beam generators using the same metamaterial platform.

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Dielectric metasurfaces for complete control of phase and polarization with subwavelength spatial resolution and high transmission

In this article we present a detailed discussion of noise sources in Fourier Domain Optical Coherence Tomography (FDOCT) setups. The performance of FDOCT with charge coupled device (CCD) cameras is compared to current standard time domain OCT systems. We describe how to measure sensitivity in the case of FDOCT and confirm the theoretically obtained values. It is shown that FDOCT systems have a large sensitivity advantage and allow for sensitivities well above 80dB, even in situations with low light levels and high speed detection.

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Performance of fourier domain vs. time domain optical coherence tomography.

Sensitive optical biosensors for unlabeled targets: a review.

Wave propagation and group velocity

We demonstrate high-speed, high-sensitivity, high-resolution optical imaging based on optical frequency-domain interferometry using a rapidly-tuned wavelength-swept laser. We derive and show experimentally that frequency-domain ranging provides a superior signal-to-noise ratio compared with conventional time-domain ranging as used in optical coherence tomography. A high sensitivity of -110 dB was obtained with a 6 mW source at an axial resolution of 13.5 microm and an A-line rate of 15.7 kHz, representing more than an order-of-magnitude improvement compared with previous OCT and interferometric imaging methods.

/pdf/high-speed-optical-frequency-domain-imaging-4wuxi22jox.pdf

High-speed optical frequency-domain imaging

Various methods, systems, and apparatuses are described in which a wavelength-division-multiplexing passive-optical-network includes a wavelength-locked light source and a wavelength-specific light source. The wavelength-locked light source may be used for communications in a first direction in the wavelength division multiplexed passive optical network to supply data signals at a first data rate. The wavelength-specific light source may be used for communications in a second direction in the wavelength division multiplexed passive optical network to supply data at a second data rate.

Methods and apparatuses to provide a wavelength-division-multiplexing passive optical network with asymmetric data rates

Tb/s class, copackaged coarse wavelength division multiplexing optical engine based on four wavelength vertical cavity surface emitting lasers (VCSELs) around 1 $\mu$ m is presented. The capability to scale bandwidth of 64 Gb/s using equalization and advanced modulation scheme, e.g., four-level pulse amplitude modulation (PAM4) is demonstrated. The capability to scale link distance of 2 km using single-mode VCSELs and standard SMF-28 fiber is demonstrated. Single-mode VCSELs error-free transmission at 25 Gb/s NRZ over 2 km of SMF-28 is achieved. Using forward-error-correction error-free transmission is possible for the PAM4 modulation over 2 km of SMF-28.

Universal Photonic Interconnect for Data Centers

A system for passive optical alignment includes an through optical via formed through a substrate, an optical transmission medium secured to a first side of the substrate such that the optical transmission medium is aligned with the through optical via, and an optoelectronic component secured to a second side of the substrate such that the active region of said optoelectronic component is aligned with the through optical via.

Passive optical alignment

We show that a multimode fiber can support both single-mode “Si-Photonics” and multimode VCSEL technologies. This allows designers of data centers and optical backplanes to install one fiber infrastructure that is compatible with both technologies.

Interoperability of single-mode and multimode data links for data center and optical backplane applications

Tb/s class, co-packaged CWDM optical engine based on 4 wavelength VCSELs around 1μm is presented. The capability to scale bandwidth and link distance > 2km using single mode VCSELs and standard SMF28 fiber is demonstrated.

Wayne V. Sorin

Papers

Methods and apparatuses to provide a wavelength-division-multiplexing passive optical network with asymmetric data rates

Universal Photonic Interconnect for Data Centers

Passive optical alignment

Interoperability of single-mode and multimode data links for data center and optical backplane applications

Universal photonic interconnect for data centers