Showing papers on "Interferometry published in 2009"
TL;DR: The development of wave optics for light brought many new insights into our understanding of physics, driven by fundamental experiments like the ones by Young, Fizeau, Michelson-Morley and others as mentioned in this paper.
Abstract: The development of wave optics for light brought many new insights into our understanding of physics, driven by fundamental experiments like the ones by Young, Fizeau, Michelson-Morley and others. Quantum mechanics, and especially the de Broglie’s postulate relating the momentum p of a particle to the wave vector k of an matter wave: k = 2 λ = p/ℏ, suggested that wave optical experiments should be also possible with massive particles (see table 1), and over the last 40 years electron and neutron interferometers have demonstrated many fundamental aspects of quantum mechanics [1].
1,194 citations
Journal Article•
TL;DR: In this article, the authors present CLEAN, a method for high-resolution radio interferometry that avoids the effects of the prominent and extended sidelobe patterns of the corresponding synthesized beam.
Abstract: In high-resolution radio interferometry it is often impossible for practical reasons to arrange for the measured baselines to be regularly distributed. The standard Fourier inversion methods may then produce maps which are seriously confused by the effects of the prominent and extended sidelobe patterns of the corresponding synthesized beam. Some methods which have been proposed for avoiding these difficulties are discussed. In particular, the procedure CLEAN is described in some detail. This has been successfully applied to measurements taken with several different radio telescopes and appears to be the best method available at the time of writing.
960 citations
13 Feb 2009
774 citations
TL;DR: An interferometric weak value technique to amplify very small transverse deflections of an optical beam by entangling the beam's transverse degrees of freedom with the which-path states of a Sagnac interferometer is reported on.
Abstract: We report on the use of an interferometric weak value technique to amplify very small transverse deflections of an optical beam. By entangling the beam's transverse degrees of freedom with the which-path states of a Sagnac interferometer, it is possible to realize an optical amplifier for polarization independent deflections. The theory for the interferometric weak value amplification method is presented along with the experimental results, which are in good agreement. Of particular interest, we measured the angular deflection of a mirror down to 400+/-200 frad and the linear travel of a piezo actuator down to 14+/-7 fm.
622 citations
TL;DR: In this paper, an approach to achieve simultaneous measurement of refractive index and temperature is proposed by using a Mach-Zehnder interferometer realized on tapered single-mode optical fiber.
Abstract: An approach to achieve simultaneous measurement of refractive index and temperature is proposed by using a Mach–Zehnder interferometer realized on tapered single-mode optical fiber. The attenuation peak wavelength of the interference with specific order in the transmission spectrum shifts with changes in the environmental refractive index and temperature. By utilizing S-band and C/L-band light sources, simultaneous discrimination of refractive index and temperature with the tapered fiber Mach–Zehnder interferometer is demonstrated with the corresponding sensitivities of −23.188 nm/RIU (refractive index unit) and 0.071 nm/ °C, and −26.087 nm/RIU (blueshift) and 0.077 nm/°C (redshift) for the interference orders of 169 and 144, respectively.
551 citations
TL;DR: The quantitative refractive index map can potentially serve as an intrinsic assay to provide the molecular concentrations without the addition of exogenous agents and also to provide a method for studying the light scattering properties of single cells.
Abstract: We report the experimental implementation of optical diffraction tomography for quantitative 3D mapping of refractive index in live biological cells. Using a heterodyne Mach-Zehnder interferometer, we record complex field images of light transmitted through a sample with varying directions of illumination. To quantitatively reconstruct the 3D map of complex refractive index in live cells, we apply optical diffraction tomography based on the Rytov approximation. In this way, the effect of diffraction is taken into account in the reconstruction process and diffraction-free high resolution 3D images are obtained throughout the entire sample volume. The quantitative refractive index map can potentially serve as an intrinsic assay to provide the molecular concentrations without the addition of exogenous agents and also to provide a method for studying the light scattering properties of single cells.
508 citations
TL;DR: A transition between energy levels at an avoided crossing is known as a Landau-Zener transition and is referred to as the Stuckelberg phase as discussed by the authors. But, the transition may result in constructive or destructive interference.
Abstract: A transition between energy levels at an avoided crossing is known as a Landau-Zener transition. When a two-level system (TLS) is subject to periodic driving with sufficiently large amplitude, a sequence of transitions occurs. The phase accumulated between transitions (commonly known as the Stuckelberg phase) may result in constructive or destructive interference. Accordingly, the physical observables of the system exhibit periodic dependence on the various system parameters. This phenomenon is often referred to as Landau-Zener-Stuckelberg (LZS) interferometry. Phenomena related to LZS interferometry occur in a variety of physical systems. In particular, recent experiments on LZS interferometry in superconducting TLSs (qubits) have demonstrated the potential for using this kind of interferometry as an effective tool for obtaining the parameters characterizing the TLS as well as its interaction with the control fields and with the environment. Furthermore, strong driving could allow for fast and reliable control of the quantum system. Here we review recent experimental results on LZS interferometry, and we present related theory.
488 citations
TL;DR: Diffraction limited images of living COS-7 cells are presented, with a particular focus on the membrane and organelle dynamics.
Abstract: Phase imaging with a high-resolution wavefront sensor is considered. This is based on a quadriwave lateral shearing interferometer mounted on a non-modified transmission white-light microscope. The measurement technology is explained both in the scope of wave optics and geometrical optics in order to discuss its implementation on a conventional microscope. In particular we consider the effect of a non spatially coherent source on the phase-image signal-to-noise ratio. Precise measurements of the phase-shift introduced by microscopic beads or giant unilamellar vesicles validate the principle and show the accuracy of the methods. Diffraction limited images of living COS-7 cells are then presented, with a particular focus on the membrane and organelle dynamics.
451 citations
TL;DR: The results reveal the benchmark for precision in optical interferometry, and it is shown that the obtained precision beats the standard quantum limit, thus leading to a significant improvement compared to classical interferometers.
Abstract: By using a systematic optimization approach, we determine quantum states of light with definite photon number leading to the best possible precision in optical two-mode interferometry. Our treatment takes into account the experimentally relevant situation of photon losses. Our results thus reveal the benchmark for precision in optical interferometry. Although this boundary is generally worse than the Heisenberg limit, we show that the obtained precision beats the standard quantum limit, thus leading to a significant improvement compared to classical interferometers. We furthermore discuss alternative states and strategies to the optimized states which are easier to generate at the cost of only slightly lower precision.
395 citations
TL;DR: In this paper, the authors present measurements on optomechanical systems exhibiting radiofrequency (62-122 MHz) mechanical modes, cooled to very low occupancy using a combination of cryogenic precooling and resolved-sideband laser cooling.
Abstract: The theory of quantum measurement of mechanical motion, describing the mutual coupling of a meter and a measured object, predicts a variety of phenomena such as quantum backaction, quantum correlations and non-classical states of motion. In spite of great experimental efforts, mostly based on nano-electromechanical systems, probing these in a laboratory setting has as yet eluded researchers. Cavity optomechanical systems, in which a high-quality optical resonator is parametrically coupled to a mechanical oscillator, hold great promise as a route towards the observation of such effects with macroscopic oscillators. Here, we present measurements on optomechanical systems exhibiting radiofrequency (62–122 MHz) mechanical modes, cooled to very low occupancy using a combination of cryogenic precooling and resolved-sideband laser cooling. The lowest achieved occupancy is n∼63. Optical measurements of these ultracold oscillators’ motion are shown to perform in a near-ideal manner, exhibiting an imprecision–backaction product about one order of magnitude lower than the results obtained with nano-electromechanical transducers. Optomechanical systems in which a high-quality optical resonator is coupled to a mechanical oscillator hold great promise for examining quantum effects in relatively large structures. As a step towards this, a silica microtoroid has now been cooled to the point that it has just 63 thermal quanta.
389 citations
TL;DR: In this article, a generic imaging technique based on convex optimization for global minimization problems is proposed for radiometric reconstruction of sparse or compressible signals in radio interferometry.
Abstract: Radio interferometry probes astrophysical signals through incomplete and noisy Fourier measurements. The theory of compressed sensing demonstrates that such measurements may actually suffice for accurate reconstruction of sparse or compressible signals. We propose new generic imaging techniques based on convex optimization for global minimization problems defined in this context. The versatility of the framework notably allows introduction of specific prior information on the signals, which offers the possibility of significant improvements of reconstruction relative to the standard local matching pursuit algorithm CLEAN used in radio astronomy. We illustrate the potential of the approach by studying reconstruction performances on simulations of two different kinds of signals observed with very generic interferometric configurations. The first kind is an intensity field of compact astrophysical objects. The second kind is the imprint of cosmic strings in the temperature field of the cosmic microwave background radiation, of particular interest for cosmology.
TL;DR: A dual sensing fiber-optic hydrophone that can make simultaneous measurements of acoustic pressure and temperature at the same location has been developed and showed that the sensor is not susceptible to viscous heating, is able to withstand high intensity fields, and can simultaneously acquire acoustic waveforms while monitoring induced temperature rises.
Abstract: A dual sensing fiber-optic hydrophone that can make simultaneous measurements of acoustic pressure and temperature at the same location has been developed for characterizing ultrasound fields and ultrasound-induced heating. The transduction mechanism is based on the detection of acoustically- and thermally-induced thickness changes in a polymer film Fabry-Perot interferometer deposited at the tip of a single mode optical fiber. The sensor provides a peak noise-equivalent pressure of 15 kPa (at 5 MHz, over a 20 MHz measurement bandwidth), an acoustic bandwidth of 50 MHz, and an optically defined element size of 10 microm. As well as measuring acoustic pressure, temperature changes up to 70 degrees C can be measured, with a resolution of 0.34 degrees C. To evaluate the thermal measurement capability of the sensor, measurements were made at the focus of a high-intensity focused ultrasound (HIFU) field in a tissue mimicking phantom. These showed that the sensor is not susceptible to viscous heating, is able to withstand high intensity fields, and can simultaneously acquire acoustic waveforms while monitoring induced temperature rises. These attributes, along with flexibility, small physical size (OD approximately 150 microm), immunity to Electro-Magnetic Interference (EMI), and low sensor cost, suggest that this type of hydrophone may provide a practical alternative to piezoelectric based hydrophones.
TL;DR: Critical performance parameters such as the ldquovisibility of the groundrdquo at L- and P-band as well as temporal decorrelation in short-time repeat-pass interferometry are discussed and quantitatively assessed.
Abstract: This paper addresses the potential and limitations of polarimetric synthetic aperture radar (SAR) interferometry (Pol-InSAR) inversion techniques for quantitative forest-parameter estimation in tropical forests by making use of the unique data set acquired in the frame of the second Indonesian Airborne Radar Experiment (INDREX-II) campaign - including Pol-InSAR, light detection and ranging (LIDAR), and ground measurements - over typical Southeast Asia forest formations. The performance of Pol-InSAR inversion is not only assessed primarily at L- and P-band but also at higher frequencies, namely, X-band. critical performance parameters such as the ldquovisibility of the groundrdquo at L- and P-band as well as temporal decorrelation in short-time repeat-pass interferometry are discussed and quantitatively assessed. Inversion performance is validated against LIDAR and ground measurements over different test sites.
TL;DR: A simple and compact modal interferometer for applications in refractometry that is highly stable over time, has low temperature sensitivity, and is suitable for measuring indices in the 1.330-1.440 range is reported.
Abstract: We report a simple and compact modal interferometer for applications in refractometry. The device consists of a stub of large-mode-area photonic crystal fiber (PCF) spliced between standard single-mode fibers. In the splice regions the voids of the PCF are fully collapsed, thus allowing the coupling and recombination of PCF core and cladding modes. The device is highly stable over time, has low temperature sensitivity, and is suitable for measuring indices in the 1.330-1.440 range. The measure of the refractive index is carried out by monitoring the shift of the interference pattern.
Book•
13 Apr 2009
TL;DR: In this paper, the authors present a taxonomy of the three revolutions of optical imaging, including the first three, the fourth revolution, the fifth revolution, and the present revolution.
Abstract: Preface. Acknowledgments. 1. Past, present and future. 1.1 Three revolutions. 1.2 Computational imaging. 1.3 Overview. 1.4 The fourth revolution. Problems. 2. Geometric imaging. 2.1 Visibility. 2.2 Optical elements. 2.3 Focal imaging. 2.4 Imaging systems. 2.5 Pinhole and coded aperture imaging. 2.6 Projection tomography. 2.7 Reference structure tomography. Problems. 3. Analysis. 3.1 Analytical tools. 3.2 Fields and transformations. 3.3 Fourier analysis. 3.4 Transfer functions and filters. 3.5 The Fresnel transformation. 3.6 The Whittaker-Shannon sampling theorem. 3.7 Discrete analysis of linear transformations. 3.8 Multiscale sampling. 3.9 B-splines. 3.10 Wavelets. Problems. 4. Wave imaging. 4.1 Waves and fields. 4.2 Wave model for optical fields. 4.3 Wave propagation. 4.4 Diffraction. 4.5 Wave analysis of optical elements. 4.6 Wave propagation through thin lenses. 4.7 Fourier analysis of wave imaging. 4.8 Holography. Problems. 5. Detection. 5.1 The Optoelectronic interface. 5.2 Quantum mechanics of optical detection. 5.3 Optoelectronic detectors. 5.3.1 Photoconductive detectors. 5.3.2 Photodiodes. 5.4 Physical characteristics of optical detectors. 5.5 Noise. 5.6 Charge coupled devices. 5.7 Active pixel sensors. 5.8 Infrared focal plane arrays. Problems. 6. Coherence imaging. 6.1 Coherence and spectral fields. 6.2 Coherence propagation. 6.3 Measuring coherence. 6.4 Fourier analysis of coherence imaging. 6.5 Optical coherence tomography. 6.6 Modal analysis. 6.7 Radiometry. Problems. 7. Sampling. 7.1 Samples and pixels. 7.2 Image plane sampling on electronic detector arrays. 7.3 Color imaging. 7.4 Practical sampling models. 7.5 Generalized sampling. Problems. 8. Coding and inverse problems. 8.1 Coding taxonomy. 8.2 Pixel coding. 8.3 Convolutional coding. 8.4 Implicit coding. 8.5 Inverse problems. Problems. 9. Spectroscopy. 9.1 Spectral measurements. 9.2 Spatially dispersive spectroscopy. 9.3 Coded aperture spectroscopy. 9.4 Interferometric Spectroscopy. 9.5 Resonant spectroscopy. 9.6 Spectroscopic filters. 9.7 Tunable filters. 9.8 2D spectroscopy. Problems. 10. Computational imaging. 10.1 Imaging systems. 10.2 Depth of field. 10.3 Resolution. 10.4 Multiple aperture imaging. 10.5 Generalized sampling revisited. 10.6 Spectral imaging. Problems. References.
Patent•
17 Jul 2009
TL;DR: In this paper, an optical coherence tomography-based ophthalmic testing center system is presented, which includes an eyepiece for receiving at least one eye of a user or subject.
Abstract: In accordance with one aspect of the present invention, an optical coherence tomography-based ophthalmic testing center system includes an optical coherence tomography instrument comprising an eyepiece for receiving at least one eye of a user or subject; a light source that outputs light that is directed through the eyepiece into the user's or subject's eye, an interferometer configured to produce optical interference using light reflected from the user's/subject's eye, an optical detector disposed so as to detect said optical interference; and a processing unit coupled to the detector. The ophthalmic testing center system can be configured to perform a multitude of self-administered functional and/or structural ophthalmic tests and output the test data
TL;DR: In this article, an inverse interferometer geometry is investigated that offers significant advantages for grating fabrication and for the application of the method in computed tomography (CT) scanners, where the sample should be placed in front of or behind the phase grating.
Abstract: Phase-contrast imaging using conventional polychromatic x-ray sources and grating interferometers has been developed and demonstrated for x-ray energies up to 60 keV. Here, we conduct an analysis of possible grating configurations for this technique and present further geometrical arrangements not considered so far. An inverse interferometer geometry is investigated that offers significant advantages for grating fabrication and for the application of the method in computed tomography (CT) scanners. We derive and measure the interferometer’s angular sensitivity for both the inverse and the conventional configuration as a function of the sample position. Thereby, we show that both arrangements are equally sensitive and that the highest sensitivity is obtained, when the investigated object is close to the interferometer’s phase grating. We also discuss the question whether the sample should be placed in front of or behind the phase grating. For CT applications, we propose an inverse geometry with the sample ...
Patent•
17 Mar 2009
TL;DR: In this paper, an optical coherence tomography instrument consisting of an eyepiece for receiving at least one eye of a user is provided; a light source that outputs light that is directed through the eye into the user's eye, and an interferometer configured to produce optical interference using light reflected from the eye; an optical detector disposed so as to detect said optical interference; and electronics coupled to the detector.
Abstract: In accordance with one aspect of the present invention, an optical coherence tomography instrument comprises an eyepiece for receiving at least one eye of a user is provided; a light source that outputs light that is directed through the eyepiece into the user's eye; an interferometer configured to produce optical interference using light reflected from the user's eye; an optical detector disposed so as to detect said optical interference; and electronics coupled to the detector. The electronics can be configured to perform a risk assessment analysis based on optical coherence tomography measurements obtained using the interferometer. An output device can be electrically coupled to the electronics, and may be configured to output the risk assessment to the user through the output device. The optical coherence tomography instrument can be self-administered, and the eyepiece can be a monocular system or a binocular system.
TL;DR: In this paper, the authors presented the full evaluation of a cold-atom gyroscope based on atom interferometry and demonstrated that the acceleration noise can be efficiently removed from the rotation signal, allowing them to reach the fundamental limit of the quantum projection noise for short term measurements.
Abstract: We present the full evaluation of a cold-atom gyroscope based on atom interferometry. We have performed extensive studies to determine the systematic errors, scale factor and sensitivity. We demonstrate that the acceleration noise can be efficiently removed from the rotation signal, allowing us to reach the fundamental limit of the quantum projection noise for short term measurements. The technical limits to the long term sensitivity and accuracy have been identified, clearing the way for the next generation of ultrasensitive atom gyroscopes.
TL;DR: In this paper, the resonant frequency of a 2.7 kg pendulum mode was dynamically shifted to lie within this optimal band, where its effective temperature falls as low as 1.4 μK and its occupation number reaches about 200 quanta.
Abstract: We introduce a novel cooling technique capable of approaching the quantum ground state of a kilogram-scale system—an interferometric gravitational wave detector. The detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) operate within a factor of 10 of the standard quantum limit (SQL), providing a displacement sensitivity of 10−18 m in a 100 Hz band centered on 150 Hz. With a new feedback strategy, we dynamically shift the resonant frequency of a 2.7 kg pendulum mode to lie within this optimal band, where its effective temperature falls as low as 1.4 μK, and its occupation number reaches about 200 quanta. This work shows how the exquisite sensitivity necessary to detect gravitational waves can be made available to probe the validity of quantum mechanics on an enormous mass scale.
TL;DR: In this paper, an optical analogue of the superconducting Josephson interferometer was proposed to enable detailed studies of the role that dissipation has in strongly correlated quantum-optical systems.
Abstract: A proposed device—an optical analogue of the superconducting Josephson interferometer—might enable detailed studies of the role that dissipation has in strongly correlated quantum-optical systems.
TL;DR: The use of white synchrotron radiation for high-speed X-ray phase imaging and tomography in combination with anX-ray Talbot interferometer is demonstrated, suggesting a breakthrough for time-resolved three-dimensional observation of objects that weakly absorb X-rays, such as soft material and biological objects.
Abstract: X-ray Talbot interferometry, which uses two transmission gratings, has the advantage that broad energy bandwidth x-rays can be used. We demonstrate the use of white synchrotron radiation for high-speed X-ray phase imaging and tomography in combination with an X-ray Talbot interferometer. The moire fringe visibility over 20% was attained, enabling quantitative phase measurement. X-ray phase images with a frame rate of 500 f/s and an X-ray phase tomogram with a scan time of 0.5 s were obtained successfully. This result suggests a breakthrough for time-resolved three-dimensional observation of objects that weakly absorb X-rays, such as soft material and biological objects.
TL;DR: In this article, two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford 10m atom interferer presently under construction, are proposed.
TL;DR: The differences between interferometric processing of strip map and of spotlight SAR data are elucidated, and adequate algorithms for key processing steps such as azimuth Doppler filtering are outlined.
Abstract: Recently, synthetic aperture radar (SAR) data with 1-m resolution acquired by satellites in spotlight mode became available to the public. In this paper, we elucidate the differences between interferometric processing of strip map and of spotlight SAR data, and we outline adequate algorithms for key processing steps such as azimuth Doppler filtering. We further present first TerraSAR-X spotlight interferograms, together with an evaluation of the paraeters that are critical for interferometry. Our results indicate a very good geometric accuracy, stability, and phase fidelity of the TerraSAR-X sensor and its products. From the interferograms, we are able to determine the heights of larger buildings and millimeter-scale structural deformation in several examples. The high detail level of imaged buildings and the good temporal phase coherence of urban areas in X-band make spotlight interferometry an exciting processing technique that enables new applications such as surveying individual buildings.
TL;DR: Astrophotonics, a field that has already created new photonic capabilities, is now extending its reach down to the Rayleigh scattering limit at ultraviolet wavelengths, and out to mid infrared wavelengths beyond 2500 nm.
Abstract: Astrophotonics lies at the interface of astronomy and photonics. This burgeoning field has emerged over the past decade in response to the increasing demands of astronomical instrumentation. Early successes include: (i) planar waveguides to combine signals from widely spaced telescopes in stellar interferometry; (ii) frequency combs for ultra-high precision spectroscopy to detect planets around nearby stars; (iii) ultra-broadband fibre Bragg gratings to suppress unwanted background; (iv) photonic lanterns that allow single-mode behaviour within a multimode fibre; (v) planar waveguides to miniaturize astronomical spectrographs; (vi) large mode area fibres to generate artificial stars in the upper atmosphere for adaptive optics correction; (vii) liquid crystal polymers in optical vortex coronographs and adaptive optics systems. Astrophotonics, a field that has already created new photonic capabilities, is now extending its reach down to the Rayleigh scattering limit at ultraviolet wavelengths, and out to mid infrared wavelengths beyond 2500nm.
TL;DR: A phase-shifting interferometric technique for imaging live biological cells in growth media, while optimizing spatial resolution and enabling potential real-time measurement capabilities is presented.
Abstract: We present a phase-shifting interferometric technique for imaging live biological cells in growth media, while optimizing spatial resolution and enabling potential real-time measurement capabilities. The technique uses slightly-off-axis interferometry which requires less detector bandwidth than traditional off-axis interferometry and fewer measurements than traditional on-axis interferometry. Experimental and theoretical comparisons between the proposed method and these traditional interferometric approaches are given. The method is experimentally demonstrated via phase microcopy of live human skin cancer cells.
TL;DR: In this paper, a Mach-Zehnder interferometer with two abrupt singlemode fiber tapers is simulated, constructed, and demonstrated, which has an insertion loss of 5 dB and an extinction ratio over 15 dB.
Abstract: A Mach-Zehnder interferometer with two abrupt single-mode fiber tapers is simulated, constructed, and demonstrated. The interferometer has an insertion loss of 5 dB and an extinction ratio over 15 dB. The interferometer is tested as a strain sensor based on the maximum attenuation wavelength shift with a comparable sensitivity (slope: 2000 nm/ epsiv, R 2 = 0.996) with long-period-grating-type sensor and promises low fabrication cost.
TL;DR: The measurement accuracy of MAI was improved using flat-Earth correction and coherence enhancement, with particular consideration given to coherence improvement, as well as to computational efficiency.
Abstract: Multiple-aperture synthetic aperture radar (SAR) interferometry (MAI) enables the measurement of along-track surface deformations by means of split-beam SAR processing. This paper examines the effects of flat-Earth and topographic phases on the MAI phase and derives formulas to correct them. Detailed MAI processing steps are introduced and discussed with particular consideration given to coherence improvement, as well as to computational efficiency. Forward- and backward-looking MAI pairs have different perpendicular baselines, which play a key role in phase distortion; consequently, an orbital deviation of only a few centimeters could result in a significant flat-Earth phase. A second-order polynomial model was used to estimate the perpendicular baseline difference. European Remote Sensing 2 satellite SAR data sets of the Hector Mine earthquake event in 1999 were used for performance evaluation. The proposed processing with the flat-Earth and topographic phase corrections achieved precision of along-track deformation ranging from 10.2 to 13.1 cm. Two coseismic pairs were compared and the standard deviation of the difference between the two independent measurements was 7.0 cm, with a mean difference of -0.24 cm. Thus, the measurement accuracy of MAI was improved using flat-Earth correction and coherence enhancement.
TL;DR: A key proof-of-principle demonstration of an externallycontrolled photonic quantum circuit based upon UV-written waveguide technology and non-classical interference of photon pairs in a Mach-Zehnder interferometer constructed with X couplers in an integrated optical circuit.
Abstract: Scalable photonic quantum technologies are based on multiple nested interferometers. To realize this architecture, integrated optical structures are needed to ensure stable, controllable, and repeatable operation. Here we show a key proof-of-principle demonstration of an externally-controlled photonic quantum circuit based upon UV-written waveguide technology. In particular, we present non-classical interference of photon pairs in a Mach-Zehnder interferometer constructed with X couplers in an integrated optical circuit with a thermo-optic phase shifter in one of the interferometer arms.