In this paper, we present the results of extensive single-radius bend loss measurements for two different fibers over wide ranges wavelength (800-1600 nm) and curvature radius (13.5-27.5 mm). A new formula is also derived, allowing a good fit experimental data whole range both parameters. Using an equivalent step-index (ESI) approach obtain agreement between estimated real parameters: e.g., cutoff wavelengths are within 1%.

An analysis of the second-order conditional statistics speckle patterns is developed, under assumption Gaussian field components. After deriving distributions and moments intensity phase for a joint measurement performed in presence partial correlation, results phase-variances are applied to determine accuracy limits speckle-pattern interferometric measurements.

We analyze the random errors occurring in interferometric measurements because of speckle pattern regime, when remote target is a diffusing surface. First, we review statistical properties and discuss amplitude fading that affecting self-mixing interferometer (SMI) signal methods to alleviate it. Second, derive intra-speckle phase using bivariate conditional probability, find noise-equivalent-displacement for small displacement Δ proportional ratio longitudinal size s <sub...

We propose an array of non-imaging micro-concentrators as a mean to recover the loss sensitivity due area fill-factor. This is particularly important for those image photo detectors in which complex circuit functions are required and substantial fraction pixel consumed, like e.g., 3D camera, SPAD arrays, fluorescence analyzers, etc., but also CMOS sensors. So far, low fill-factor was unacceptable precluding from development such devices, whereas by using concentrator recovery possible, up...

A unified description of multiple feedback common-gate low-noise amplifiers (LNAs) is presented, providing analytical expressions for gain, noise figure, linearity, and stability conditions. Moreover, from the theory, a new methodology LNA optimization developed. This approach, called adaptive optimization, uses ability to reconfigure network match amplifier characteristics changing working Results simulation LNAs with different types are shown, they confirm theory presented.

We discuss the benefits of using microoptics concentration arrays in connection with image (or pixellated) photodetectors, terms of: 1) recovery area fill-factor; 2) reduction equivalent dark-current; 3) mitigate dead-time issues; and 4) improved dynamic range. As an example application, we describe fill-factor to array 32 × 6-μm diameter, 50-μm pitch, single photon avalanche detector (SPAD). use a microlenses, fabricated by polymer casting photoresist replica mold. demonstrate, for first...

We analyze the ultimate timing error that can be achieved in operation of a LiDAR based on time-of-flight (ToF) measurement distance using pulsed light source and two possible detectors optic receiver: (i) an avalanche photodiode APD linear mode, (ii) SPAD single photon detector. both random systematic contributions to total find latter becomes dominant at large (>10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) number detected...

We report on the design of a current-assisted photonic demodulator (CAPD) using standard 0.18-μm complementary metal-oxide-semiconductor technology and its electrooptical characterization. The device can perform both light detection demodulation in charge domain, owing to drift field generated silicon substrate by majority carrier flow. Minimum-sized 10 × μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> CAPDs exhibit direct-current...

We consider the errors introduced by speckle pattern statistics of a diffusing target in measurement large displacements made with self-mixing interferometer (SMI), sub-λ resolution and range up to meters. As source on side, we assume diffuser randomly distributed roughness. Two cases are considered: (i) developing randomness z-height profile, standard deviation σ(z), increasing from ≪λ ≫λ uncorrelated spatially (x,y), (ii) fully developed (σ(z)≫λ) but correlated various correlation sizes...

We show that the speckle phase error incurred when laser spot is scanned over diffusing surface can be made as low 10-20 μm for object sizes in range 3-10 cm. This result new, to best of our knowledge, because it usually assumed moves its size, becomes uncorrelated and measurement cannot done anymore. carry out numerical simulations process derive an analytical model evaluate noise equivalent displacement profile by a self-mixing interferometer.

In this brief, a theoretical analysis on the limits of conventional chopper stabilization technique is presented and solution conceived to improve amplifier performance proposed. The expected replicas 1/f noise at chopping frequency its multiples are attenuated by modified control. Simulations done using records real outputs showed that, following proposed approach, spectrum signal not affected while reduced more than 40 dB with respect techniques. required circuit for generation also...

Efficient and reliable Random Number Generator (RNG) are increasingly demanded in cryptographic applications, such as on-the-fly data encription/decription a general tool for protection. Main requirement of RNG is true randomness, which achievable by means physical randomness sources only. A True-RNG based on two independent Stochastic Processes (SP) presented discussed. As primary sources, radioactive decay processes used. source has many advantages over others noise since the rate any...

We demonstrate the feasibility of piezoelectric actuation waveguide devices in silica-on-silicon. Relative to commonly employed technique thermal expansion by power dissipation a resistive element, piezo drastically reduces drive-power consumption and improves switching time, from milliseconds microseconds. report experimental results using discrete piezoelement, discuss how can be implemented with integrated technologies for simultaneous fabrication large number actuators on wafer.

We present a self-mixing interferometer (SMI) vibrometer developed around laser diode with simple and compact analog processing of the fringe signal, show that this instrument can readily detect ambient vibrations—which adversely affect mechanical material-working lathes. In addition, we find out is an excellent intrusion detector, capable discovering man stepping several meters away from sensor, thus hinting at SMI application as antithief sensor.

Using an array of 32times32 plano-convex microlenses, fabricated by co-polymer casting in a photoresist replica mold, we have been able to increase the detection sensitivity SPAD (Single Photon Avalanche Detector) pixels, 50-mum pitch, up factor 35.

Taking account of the reinjection at clad/coating interface, we are able to substantially improve performance polarizers made by coils hi-bi fiber. We obtain reproducibly 45 dB extinction with a 4-turn coil selected radii, no kinks in attenuation and limited insertion loss.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The limits of the conventional chopper stabilization technique for cancelling 1/f noise are studied theoretically and with simulations. expected replicas at chopping frequency its multiples attenuated by a modified control. Simulation done using records real outputs show that spectrum signal does not change but reduced more than 40 dB. required circuit generation is also described. resulting overhead respect to solutions negligible fully acceptable.

Self-mixing interferometry (SMI) is a new scheme of having several advantages compared to standard configurations: it can work with no optical part external the laser, self-aligned, immune stray light, and measure also on target diffusing surfaces. In this paper, an overview measurements already demonstrated self-mixing presented, application kinematic quantities (displacement, vibration. etc.) as well physical (linewidth, alfa factor, etc).

We report on a 0.18µm CMOS range image sensor with 120×160 array of 10×10µm2 photonic demodulation pixels allowing for real-time 3D imaging worst-case accuracy 3.3% in the distance interval [1.2–3.7] m.

In this paper, we describe a new technique for automatic phase stepping in fiber-optic Electronic Speckle Pattern Interferometry (ESPI), useful both single-point and imaging configurations. The proposed is based on closed-loop switching of the gain sign control loop used to stabilize reference wavefront phase, with aid Proportional-Integral (P.I.) controller. Simulation experimental results are compared, showing that by synchronization signal or proper choice feedback parameters, sequence...

We present an optical vibrometer especially designed to measure small amplitude (hundreds pm several μm) vibrations at very low frequency, down 0.01 Hz. The instrument is based on a Self-Mixing Interferometer of the fringe-lock type, achieve high sensitivity and wide dynamic range. As compared previous design same principle, our free from loss due thermal drift laser wavelength; this result obtained by exploiting separate DC feedback loop acting Laser Diode bias. Experiments show good...

Self-mixing interferometry (SMI) is a new scheme of having several advantages compared to standard configurations: it can work with no optical part external the laser, self-aligned, immune stray light, and measure also on target diffusing surfaces. In this paper, an overview measurements already demonstrated self-mixing presented, application tthe kinematic quantities (displacement, vibration. etc.) as well physical (linewidth, alfa factor, etc.).

A model for the 1/f noise in large signal operation of linear passive one-port (e.g. carbon or polysilicon resistors) is given. Starting from Hooge's formula, that holds when component operated under DC bias, it shown current simply proportional to product between conductivity fluctuation and time-dependent applied component. Otherwise stated, exhibited by components arises intermodulation stochastic process "conductivity fluctuation" Detailed calculations both autocorrelation function power...