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

Methods and apparatus are provided related to opto-electronics An opto-electronic subassembly includes electrical contacts bonded to a base by way of a compliant adhesive The opto-electronic subassembly is mechanically engaged to a circuit board resulting in contact force loading of the compliant adhesive Such loading maintains electrical coupling between the electrical contacts and respective circuit pathways of the circuit board Optical signal communication between the opto-electronic subassembly and another entity is performed by way of an optical connector

Opto-electronics with compliant electrical contacts

Reflectometer using optical attenuation

In apparatus and a method for measuring the thickness of a film (13), the film (13) is illuminated with a low coherence light signal that is preferably generated from a source (12, 100) including two or more LEDs (102, 103). The light reflected from the surfaces of the film (13) is collected and coupled to an interferometer (18). The slope of the Fourier transform of the output of the signal from the interferometer (18) is measured to provide a determination of the thickness of the film (13). In the preferred embodiment, the interferometer output is sampled at fewer than two points per cycle of the low coherence light signal.

System for measuring film thickness

A system includes a laser array that receives a plurality of electrical signals and generates a plurality of optical signals driven from a corresponding member of the plurality of electrical signals, wherein the plurality of optical signals are arranged in a plurality of different groups. A coplanar router routes the plurality of optical signals to an array of optical multiplexers, such that each multiplexer receives optical signals from each of the plurality of different groups.

Coplanar routing for optical transmission

A compact Si-Ge avalanche photodiode (APD) circuit model, including carrier transit time and electrical parasitics, is demonstrated and accurately captures electrical and optical dynamics in a wide range of multiplication gain. Excellent matching between simulated and measured 30 Gb/s eye diagrams is presented.

Wayne V. Sorin

Papers

Opto-electronics with compliant electrical contacts

Reflectometer using optical attenuation

System for measuring film thickness

Coplanar routing for optical transmission

A Compact Model for Si—Ge Avalanche Photodiodes