Ghost imaging is an optical technique in which the information of object encoded correlation intensity fluctuations light. The computational version this fascinating phenomenon emulates, offline, propagation through reference arm, enabling 3D visualization a complex whose transmitted light measured by bucket detector. In Letter, we show how ghost can be used to encrypt and transmit remote party. Important features, such as key compressibility vulnerability eavesdropping, are experimentally analyzed.

Smart control of light propagation through highly scattering media is a much desired goal with major technological implications.Since interaction results in partial or complete depletion ballistic photons, it principle impossible to transmit images distances longer than the extinction length.Nevertheless, different methods for image transmission, focusing, and imaging by means wavefront have been published over past few years.In this paper we show that single-pixel optical systems, based on...

This Letter develops a framework for digital holography at optical wavelengths by merging phase-shifting interferometry with single-pixel imaging based on compressive sensing. The field diffracted an input object is sampled Hadamard patterns liquid crystal spatial light modulator. concept of camera then adapted to perform interferometric the diffraction pattern using Mach–Zehnder interferometer. Phase-shifting techniques together application backward propagation algorithm allow complex...

One challenge that has long held the attention of scientists is clearly seeing objects hidden by turbid media, as smoke, fog or biological tissue, which major implications in fields such remote sensing early diagnosis diseases. Here, we combine structured incoherent illumination and bucket detection for imaging an absorbing object completely embedded a scattering medium. A sequence low-intensity microstructured light patterns launched onto object, whose image accurately reconstructed through...

Since its discovery, the ``ghost'' diffraction phenomenon has emerged as an unconventional technique for optical imaging with very promising advantages. However, extracting intensity and phase information of a structured realistic object remains challenge. Here we show that ghost hologram can be recorded single-pixel configuration by adapting concepts from standard digital holography. The presented homodyne scheme enables nanometric depth resolution three-dimensional focusing ability shows...

Abstract Phase-sensitive optical time-domain reflectometry (ΦOTDR) is a well-established technique that provides spatio-temporal measurements of an environmental variable in real time. This unique capability being leveraged ever-increasing number applications, from energy transportation or civil security to seismology. To date, wide different approaches have been implemented, providing plethora options terms performance (resolution, acquisition bandwidth, sensitivity range). However, achieve...

Environmental chemicals may be involved in the etiology of breast cancers. Many studies have addressed association between cancer humans and agricultural pesticide exposure. Organophosphorous pesticides been used extensively to control mosquito plagues. Parathion malathion are organophosphorous a wide range sucking chewing pests field crops, fruits, vegetables. They many structural similarities with naturally occurring compounds, their primary target action insects is nervous system; they...

Dual-comb interferometry is a particularly compelling technique that relies on the phase coherence of two laser frequency combs for measuring broadband complex spectra.This method rapidly advancing field optical spectroscopy and empowering new applications, from nonlinear microscopy to ranging.Up now, most dual-comb interferometers were based modelocked lasers, whose repetition rates have restricted measurement speed ~kHz.Here we demonstrate interferometer electrooptic measures consecutive...

We present an optical system that performs Stokes polarimetric imaging with a single-pixel detector. This fact is possible by applying the theory of compressive sampling to data acquired commercial polarimeter without spatial resolution. The measurement process governed light modulator, which sequentially generates set preprogrammed intensity patterns. Experimental results are presented and discussed for object provides inhomogeneous polarization distribution.

We propose and characterize experimentally a new source of optical frequency combs for performing multi-heterodyne spectrometry. This comb modality is based on shifting loop seeded with CW monochromatic laser. The lines are generated by successive passes the laser through an acousto-optic shifter. report generation more than 1500 mutually coherent lines, without resorting to non-linear broadening phenomena or external electronic modulation. line spacing easily reconfigurable from tens MHz...

Block-based single-pixel imaging (SPI) systems use multiple detectors of a focal plane array to create highly parallel extensions camera. This Letter presents what we believe be new approach for that leverages the Talbot effect scan an object with short sequence periodic light patterns encoded on digital micromirror device (DMD). The unit cell each pattern corresponds Walsh–Hadamard (WH) matrix low dimension. To separately collect from cell, implement bucket using pixels conventional image...

Problem-Based Learning (PBL) has emerged as an innovative and effective pedagogical approach in medical education. This student-centered methodology promotes the development of critical thinking, problem-solving abilities, self- directed learning skills—competencies essential for training physicians capable meeting contemporary healthcare challenges. systematic review examines theoretical foundations PBL, implementation, evidence its effectiveness Through comprehensive analysis liter- ature...

This article explores the macroeconomic consequences of impact global financial crises. An analysis crises shows that they have a negative on country's economic growth. It has been established effect growth country’s gross domestic product (GDP), exports and imports. Nevertheless, overall indicator GDP masks significant regional differences occurred during For example, 2007–2008 crisis, while more developed economies North America, Western Europe, Japan were severely affected – along with...

We present a bidirectional recirculating frequency-shifting loop, seeded by continuous-wave (cw) laser, to perform multi-heterodyne interferometry. This fiber-optic system generates two counter-propagating "acousto-optic" frequency combs with controllable line spacing. Apart from its simple architecture, coherent averaging allows us reach acquisition times up the second scale without resorting any active stabilization mechanism. also show that relative phase between is quadratic and can be...

Dual-comb interferometry is a measurement technique that uses two laser frequency combs to retrieve complex spectra in line-by-line basis. This can be implemented with electro-optic combs, offering intrinsic mutual coherence, high acquisition speed and flexible repetition-rate operation. A challenge the operation of this kind comb dual-comb its limited optical bandwidth. Here, we use coherent spectral broadening demonstrate over entire telecommunications C band (200 lines covering ~ 40 nm,...

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Phase imaging techniques extract the optical path-length information of a scene, whereas wavefront sensors provide shape an wavefront. Since these two applications have different technical requirements, they developed their own specific technology. Here we show how to perform phase combining sampling using reconfigurable spatial light modulator with beam position detector. The result is time-multiplexed detection scheme, capable being shortened considerably by compressive sensing. This...

Electro-optic frequency comb generators are particularly promising for dual-comb spectroscopy.They provide a high degree of mutual coherence between the combs without resorting to complex feedback stabilization mechanisms.In addition, electro-optic can operate at very repetition rates, thus providing fast acquisition speeds.Here, we exploit these two features resolve rapid movement vibrating target.Our interferometer is capable combining time-of-fight information with more precise...

Acousto-optic optical frequency combs can easily produce several hundreds of mutually coherent lines from a single laser, by successive shifts in loop containing an acousto-optic shifter. They combine many advantages for multi-heterodyne interferometry and dual-comb spectroscopy. In this paper, we propose model intuitive understanding the performance steady state. Though relatively simple, qualitatively predicts effect various experimental parameters on spectral characteristics comb...

In this work we demonstrate the capability of two gain-switched optically injected semiconductor lasers to perform high-resolution dual-comb spectroscopy. The use low duty cycle pulse trains gain switch lasers, combined with optical injection, allows us obtain flat-topped frequency combs 350 lines (within 10 dB) spaced by 100 MHz. These significantly improve spectral resolution reported so far on spectroscopy laser diodes. We evaluate performance our system measuring transmission profile an...

Dual frequency comb (DFC) spectroscopy using electro-optic generators stands out for its flexibility, easy implementation, and low cost. Typically, two combs with different line spacing are generated from a common laser independent generators. This approach minimizes the impact of phase noise; however, distinct paths followed by ultimately limit attainable signal-to-noise ratio long-term stability system. In this work, common-path DFC is single modulator driven an arbitrary waveform...

Distributed optical fiber sensing (DOFS) technology has recently experienced an impressive growth in various fields including security, structural monitoring and seismology, among others. This expansion been accompanied by a speedy development of the last couple decades, reaching remarkable performance terms sensitivity, range, number independent points affordable cost per monitored point as compared with competing technologies such electrical or sensors. Phase-sensitive Optical Time-Domain...

Optical transmittance of a 90-twisted nematic liquid crystal cell inserted between crossed or parallel polarizers is neither sensitive to the molecular twist sense nor exchange extraordinary and ordinary birefringence axis at input face cell. In this article, equivalence twisted-nematic combination retardation wave plate polarization rotator fully exploited understand physical origin these ambiguities. We determine, in simple way, parameters by means standard measurements when both are...