Polarimetric optical-fibre sensor for biochemical measurements

The use of an optical-fibre polarimeter as a chemical sensor is demonstrated. The compound to be detected is allowed to adsorb onto a decladded 5 cm length of the fibre. The fibre is polarization maintaining with an elliptical fibre core and a D-shaped geometry. The overall retardation stability of this fibre polarimeter is ≈ 0.5 × 2π rad m−1 K−1. With this sensor adsorption processes of proteins can be followed on-line. The resulting relative phase retardations caused by the growth of a monolayer of antibodies (αhCG, αhSA) are 0.25 × 2π. For the much smaller protein hSA, this value is 0.1 × 2

Realization and Characterization of a Four-Channel Integrated Optical Young Interferometer

In this paper, we report the realization and characterization of a four-channel integrated optical Young interferometer (YI), which enables simultaneous and independent monitoring of three binding processes. The simultaneous and independent measurement of three different glucose concentrations shows the multi-purpose feature of such device. The phase resolution for different pairs of channels was /spl sim/1/spl times/10/sup -4/ fringes, which corresponds to a refractive index resolution of /spl sim/8.5/spl times/10/sup -8/ . The observed errors, which are caused due to mismatching of spatial frequencies of individual interference patterns with those determined from the CCD camera, have been reduced by using different reduction schemes. In addition, we have investigated a novel method for discrimination of the refractive index change from the thickness of a bound layer during an immunoreaction, as well as measuring the temperature change the takes place during such a process

A spiraled segmented waveguide sensor: Principle and experiment

A novel type of chemo-optical sensor has been designed, fabricated and characterized. The sensor is simple to fabricate, puts low demands on light source quality and shows resolution of index changes of ~ $3.10^{-8}

On-chip, CMOS-compatible, hardware-compressive integrated photonic beamformer based on WDM

We propose and experimentally demonstrate a novel, hardware-compressive architecture for broadband and continuously tunable integrated optical true-time-delay beamformers. The architecture is based on on-chip wavelength division multiplexing (WDM) that, in conjunction with the frequency-periodic response of optical ring resonator (ORR) filters, dramatically reduces the network complexity and, in turn, its area occupation on the wafer. This allows the integration of an unprecedented number of delay channels on a single chip, overcoming the main limitation of current integrated beamformers, that is, the limited capability to feed very large arrays when using a single chip. Based on this technique, a novel device is realized with TriPleXTM waveguide technology, using CMOScompatible fabrication equipment, and its functionality is demonstrated over the instantaneous 2-10 GHz bandwidth. At the best of our knowledge, this results represent at the same time the record instantaneous bandwidth (8 GHz) for an optical beamformer based on optical ring resonators(ORR), and the first demonstration of an integrated beamformer where signals from different antenna elements are processed simultaneously by individual delay lines, exploiting the periodic response of ORRs

On-chip Mach-Zehnder interferometer for OCT systems

By using integrated optics, it is possible to reduce the size and cost of a bulky optical coherence tomography (OCT) system. One of the OCT components that can be implemented on-chip is the interferometer. In this work, we present the design and characterization of a Mach-Zehnder interferometer consisting of the wavelength-independent splitters and an on-chip reference arm. The Si3N4 was chosen as the material platform as it can provide low losses while keeping the device size small. The device was characterized by using a home-built swept source OCT system. A sensitivity value of 83 dB, an axial resolution of 15.2 μm (in air) and a depth range of 2.5 mm (in air) were all obtained

System integration and radiation pattern measurements of a phased array antenna employing an integrated photonic beamformer for radio astronomy applications

In this paper we describe the system integration and the experimental demonstration of a photonically beamformed four-element receiving array antenna for radio astronomy applications. To our knowledge, the work described here is the first demonstration of the squint-free, continuously tunable beamsteering capability offered by an integrated photonic beamformer based on optical ring resonator truetime-delay units, with measured radiation patterns. The integrated beamformer is realized in a low loss, complementary metal-oxide-semiconductor (CMOS) compatible optical waveguide technology. The measurements show a wideband, continuous beamsteering operation over a steering angle of 23.5 degrees and an instantaneous bandwidth of 500 MHz limited only by the measurement setup