Single Mach-Zehnder Interferometer Research Articles

Trace detection of canine distemper virus based on surface-functionalized optic-fiber Mach–Zehnder interferometer and the Vernier effect

A surface-functionalized cascaded optic-fiber Mach–Zehnder interferometer (MZI) is proposed and fabricated for trace detection of canine distemper virus (CDV). The Vernier effect is formed based on single-mode fiber (SMF)-dislocation single-mode fiber-SMF. The two MZIs serve as the sensing arm and reference arm, respectively. The CDV antibody is modified on the sensing arm to detect CDV antigen, and the surface structure and morphology are analyzed by the atomic force microscope. The sensitivity of the cascaded MZI sensor is about 12 times than that of a single MZI. In the range of 0.1–104 pg ml−1 CDV, the detection limit of the cascaded MZI sensor is 0.1687 pg ml−1, and the response time is 25 min. The sensor also has good temperature, time stability and excellent selectivity. The biosensor has the advantages of low cost, easy preparation, high sensitivity and good selectivity, and has potential application for trace CDV detection.

Hardware Error Correction for MZI-Based Matrix Computation.

With the rapid development of artificial intelligence, the electronic system has fallen short of providing the needed computation speed. It is believed that silicon-based optoelectronic computation may be a solution, where Mach-Zehnder interferometer (MZI)-based matrix computation is the key due to its advantages of simple implementation and easy integration on a silicon wafer, but one of the concerns is the precision of the MZI method in the actual computation. This paper will identify the main hardware error sources of MZI-based matrix computation, summarize the available hardware error correction methods from the perspective of the entire MZI meshes and a single MZI device, and propose a new architecture that will largely improve the precision of MZI-based matrix computation without increasing the size of the MZI's mesh, which may lead to a fast and accurate optoelectronic computing system.

Ultra-high sensitivity gas pressure sensor based on cascaded Mach-Zehnder interferometer and Sagnac interferometer

A highly sensitive optical fiber gas pressure sensor based on Vernier effect of cascaded optical fiber Sagnac interferometer (SI) and Mach Zehnder interferometer (MZI) is proposed, and the sensing characteristics are verified. The SI consists of a 3 dB coupler and a section of panda fiber, and SI is used as a filter. As the sensing part, MZI has high sensitivity and good stability. It is composed of single-mode fiber, multimode fiber and quartz capillary. By controlling the length of two interferometers, their free spectrum ranges (FSR) are similar but not equal. Therefore, the cascade structure produces the Vernier effect, which can amplify the gas pressure sensitivity of the sensor. The experimental results show that the gas pressure sensitivity of a single MZI is only − 7.75 nm/MPa. The cascade structure can amplify the sensitivity to − 211.9 nm/MPa, and the magnification factor is 27.3, which is consistent with the theoretical analysis results. In addition, the proposed sensor has excellent repeatability and stability.

A compact realization of Feynman Reversible and NOR logic gate using Plasmonic waveguide based MZI for all-optical signal processing

The reversible logic function becomes a potential solution in the regime of optical switching and computing. The one-to-one mapping between inputs and outputs in a reversible gate is a key advantage, that prevents information loss. The reversible logic gates have shown potential applications in low-power complementary metal-oxide semiconductors and in quantum computing. Therefore, to utilize these benefits of reversible functions, we have proposed an all-optical compact circuit to realize the functioning of Feynman reversible and NOR logic gates. The proposed all-optical circuit is modeled within the footprints of 87μm by using a plasmonic metal–insulator–metal (MIM) waveguide-based Mach–Zehnder interferometer (MZI). The numerical investigation of the MZI is done by evaluating the power imbalance and extinction ratio. The results show that the optical signal propagating in a single MZI with an extinction ratio of 15.1 dB for the power difference of 0.001 W/μm (∼0.1 dB) and 0.0012 W/μm (∼0.79 dB) for logic ‘0’ and logic ‘1’, respectively. The logic ‘0’ and ‘1’ is represented by low (0.028 W/μm) and high (0.038 W/μm) power signals. At logic ‘0’ the optical signal propagates in linear arms of MZI with ‘π’ phase variation, which causes constructive interference (CI) and thrives the signal at the cross-port. For logic ‘1’ the optical signal experiences ‘0’ phase variation in linear arms of MZI, and due to destructive interference reaches its through-port. The investigated results of the proposed circuit are attained by using the finite difference time domain (FDTD) method.

Displacement-noise-free neutron interferometer for gravitational wave detection using a single Mach-Zehnder configuration

The improvement of sensitivity to gravitational waves (GWs) at lower frequencies is still challenging on account of displacement noise. One of the solutions is the neutron displacement-noise-free interferometer (DFI). We focus on a simplification of the detector configuration by taking advantage of the ability to adjust the neutron speed depending on the configuration. The new configuration consists of two beamsplitters and two mirrors, which constitute a single Mach-Zehnder interferometer (MZI). It is simpler than the configuration with two MZIs in previous research. All displacement noise of mirrors and beamsplitters can be canceled in the frequency domain. This cancellation can be explained intuitively using a phasor diagram.

A Microscale Numerical Analysis of Ex-OR and Ex-NOR Logic Gates by Using Single Plasmonic MZI

This work is focused on a detailed mathematical and numerical simulation–based analysis of Ex-OR and Ex-NOR logic gates at microscale by employing metal-insulator-metal (MIM) plasmonic waveguide–based Mach-Zehnder interferometer (MZI). The geometry of MIM waveguide is designed by considering the air as dielectric material in between silver metallic layers. The bulk plasma frequency and damping constant of silver metallic layers are considered as ωp = 140 × 1014 rad/s and $${\varvec{\gamma}}=$$ 0.4 × 1014 rad/s, respectively. A nonlinear Kerr-material with response in the order of picosecond is employed in linear arms of MZI to switch the phase of optical signals. The design of single MZI is modelled within the footprints of 19 × 3 µm with a high extinction ratio (ER) of 29 dB. The phase change property of MZI is utilized to validate the operation of Ex-OR and Ex-NOR gates. The results suggest that the proposed plasmonic-based logic gates can pave the path for efficient all optical signal processing system.

Numerical simulation of all-optical logic functions at micrometer scale by using plasmonic Metal-Insulator-Metal (MIM) waveguides

All-optical integrated circuits are quite useful in the regime of ultrafast computing to overcome the limitations of existing electronic components. In this work, we have modelled two different all-optical integrated circuits to validate the operations of OR, AND, NOR, XOR, XNOR logic gates and half-adder circuit. To cascade the integrated circuits, a plasmonic metal–insulator-metal (MIM) waveguide based Mach-Zehnder interferometer (MZI) has been used. The signal switching is attained by using MEH-PPV [poly(2-methoxy-5-(28-ethylhexyloxy)-PPV)] as nonlinear Kerr material in one linear arm of MZI. The relative linear permittivity, response time and RI of nonlinear Kerr material are 2.7225, 2.0 e−15 s, and 1.67, respectively. The switching of signal across the output ports of MZI depends on the principle of self-phase and cross-phase modulation, which depends on the power of input signals. Signal power of 0.326 W/µm and 0.828 W/µm is used for low and high intensity which corresponds to logic level ‘0′ and ‘1′, respectively. The projected integrated circuits are analyzed at the wavelength of 1550 nm with transverse magnetic (TM) polarization under the contour of perfect matched layer (PML) as boundary conditions. The results conclude that the extinction ratio (ER) of single MZI is gradually decreasing with respect to the increase in power difference. For proposed design of single MZI the attained value of ER is 24 dB at the power difference of 0.3 dB. The authentication of proposed integrated circuits is done by using finite difference time domain (FDTD) based method.

Terahertz Spoof Surface Plasmonic Logic Gates.

SummaryLogic gates are important components in integrated photonic circuitry. Here, a series of logic gates to achieve fundamental logic operations based on linear interference in spoof surface plasmon polariton waveguides are demonstrated at terahertz frequencies. A metasurface-based plasmonic source is adopted to couple free-space terahertz radiation into surface waves, followed by a funnel-shaped metasurface to efficiently couple the surface waves to the waveguides built on a domino structure. A single Mach-Zehnder waveguide interferometer can work as logic gates for four logic functions: AND, NOT, OR, and XOR. By cascading two such interferometers, NAND and NOR operations can also be achieved. Experimental investigations are supported by numerical simulations, and good agreement is obtained. The logic gates have compact sizes and high intensity contrasts for the output “1” and “0” states. More complicated functions can be envisioned and will be of great value for future terahertz integrated computing.

Design of on-chip hybrid plasmonic Mach-Zehnder interferometer for temperature and concentration detection of chemical solution

We report a compact lab-on-chip design of a Mach-Zehnder interferometer (MZI) incorporating a novel metal strip loaded horizontal slot hybrid plasmonic waveguide (HSHPW) in the sensing arm and a dielectric horizontal slot (DHS) waveguide in the reference arm. The HSHPW is optimized to confine a high ∼60% and ∼82% evanescent optical field in the low index dielectric slot and an active sensing region, respectively which enhance the device sensitivity with a comparative lower propagation loss than a typical plasmonic waveguide. We report here a single MZI configuration which not only exhibits an excellent temperature sensitivity of 243.9 pm/°C but also liquid concentration sensitivity of 437.3 nm/RIU for a 40 μm long HSHPW. To mitigate loss arising from each section such as butt coupling and plasmonic modal losses, the HSHPW has been optimized by incorporating an asymmetric power splitter which shows a considerable improvement in the fringe visibility and device insertion loss. Thus, the proposed single MZI design shows an excellent response to the temperature and liquid concentration sensing with a maximum total loss and extinction ratio of 2.56 dB and>25 dB, respectively. A much simpler CMOS friendly compact design is also found to have a great robustness to the fabrication tolerances.

Mode-locking evolution in ring fiber lasers with tunable repetition rate

We have applied a simple approach to analyze behavior of the harmonically mode-locked fiber laser incorporating an adjustable Mach-Zehnder interferometer (MZI). Our model is able to describe key features of the laser outputs and explore limitations of physical mechanisms responsible for laser operation at different pulse repetition rates tuned over a whole GHz range. At low repetition rates the laser operates as a harmonically mode-locked soliton laser triggered by a fast saturable absorber. At high repetition rates the laser mode-locking occurs due to dissipative four-wave mixing seeded by MZI and gain spectrum filtering. However, the laser stability in this regime is rather low due to poor mode selectivity provided by MZI that is able to support the desired laser operation just near the lasing threshold. The use of a double MZI instead of a single MZI could improve the laser stability and extends the range of the laser tunability. The model predicts a gap between two repetitive rate ranges where pulse train generation is not supported.

Compact, flexible and versatile photonic differentiator using silicon Mach-Zehnder interferometers

We propose and experimentally demonstrate the flexibility and versatility of photonic differentiators using a silicon-based Mach-Zehnder Interferometer (MZI) structure. Two differentiation schemes are investigated. In the first scheme, we demonstrate high-order photonic field differentiators using on-chip cascaded MZIs, including first-, second-, and third-order differentiators. For single Gaussian optical pulse injection, the average deviations of all differentiators are less than 6.5%. In the second scheme, we demonstrate multifunctional differentiators, including intensity differentiator and field differentiator, using an on-chip single MZI structure. These different differentiator forms rely on the relative shift between the probe wavelength and the MZI resonant notch. Our schemes show the advantages of compact footprint, flexible functions and versatile differentiation forms. For example, high order field differentiators can be used to generate complex temporal waveforms, such as high order Hermite-Gaussian waveforms. And intensity differentiators are useful for ultra-wideband pulse generation.

Single Mach–Zehnder interferometer based optical Boolean logic gates

In this paper, we demonstrate different optical logic gates using a single Mach-Zehnder interferometer with controlled phase modulators in each arm. The operational conditions to obtain 16 optical logic circuits, using the same design, are investigated and are a result of a constructive or destructive interference process. The proposed configuration presents significant low complexity and high scalability, and its feasibility is evaluated through numerical simulations.

Linear optical Fredkin gate based on partial-SWAP gate

We propose a scheme for linear optical quantum Fredkin gate based on the combination of recently experimentally demonstrated linear optical partial-SWAP gate and controlled-Z gates. Both heralded gate and simplified post-selected gate operating in the coincidence basis are designed. The suggested setups have a simple structure and require stabilization of only a single Mach-Zehnder interferometer. A proof-of-principle experimental demonstration of the post-selected Fredkin gate appears to be feasible and within the reach of current technology.

Measuring the Complete Transverse Spatial Mode Spectrum of a Wave Field

We put forward a method that allows the experimental determination of the entire spatial mode spectrum of any arbitrary monochromatic wave field in a plane normal to its propagation direction. For coherent optical fields, our spatial spectrum analyzer can be implemented with a small number of benchmark refractive elements embedded in a single Mach-Zehnder interferometer. We detail an efficient setup for measuring in the Hermite-Gaussian mode basis. Our scheme should also be feasible in the context of atom optics for analyzing the spatial profiles of macroscopic matter waves.

10 Gb/s Reconfigurable Optical Logic Gate Using a Single Hybrid-Integrated SOA-MZI

A novel reconfigurable Boolean device based on a single Mach-Zehnder interferometer with semiconductor optical amplifiers is demonstrated at 10 Gb/s using intensity return-to-zero modulated signals. The experimental results show that the device can be dynamically reconfigured to operate as a logic XOR, AND, OR, and NOT gate using optical switches. By properly adjusting the input powers, an extinction ratio higher than 10 dB may be obtained. The potential of integration of this architecture makes it an interesting approach in photonic computing and optical signal processing.

Cascaded Operation of a 2R Burst-Mode Regenerator for Optical Burst Switching Network Transmission

We demonstrate the cascaded operation of an all-optical 2R burst-mode regenerator consisting of a single Mach-Zehnder interferometer, using a loop configuration that introduces a 6-dB power variation on each recirculation of the data. The device is shown to regenerate error-free 10-Gb/s data streams for up to six successive loop recirculations.

Comparison of all-optical co- and counter-propagating high-speed signal processing in SOA-based Mach-Zehnder interferometers

The all-optical signal processing performance of a Mach–Zehnder interferometer (MZI) is investigated. Calculated switching windows are used to investigate and understand the physical mechanisms limiting the high speed performance. Especially, the co- and counter-propagating operation of the MZI is discussed and important differences in the performance for the two schemes are addressed. The non-regenerative all-optical clear and drop functionality is investigated for a 2, 4 and 8 × 40 Gbit/s signal, showing good performance in the co-propagating case. Regenerative simultaneous clear and drop functionality in a single MZI is demonstrated experimentally and compared to the large signal model predictions.

Factoring and Fourier transformation with a Mach-Zehnder interferometer

The scheme of Clauser and Dowling [Phys. Rev. A 53, 4587 (1996)] for factoring $N$ by means of an $N$-slit interference experiment is translated into an experiment with a single Mach-Zehnder interferometer. With dispersive phase shifters, the ratio of the coherence length to wavelength limits the numbers that can be factored. A conservative estimate permits $N\ensuremath{\approx}{10}^{7}$. It is furthermore shown that sine and cosine Fourier coefficients of a real periodic function can be obtained with such an interferometer.

Two-photon interference in a Mach-Zehnder interferometer.

Pairs of 826.8-nm correlated photons, generated by parametrically down-converting 413.4-nm krypton-ion laser light, are directed into a single Mach-Zehnder interferometer such that each photon of the pair enters a different input port. The rate of coincidence at the two output ports displays oscillations (as the path-length difference is swept) with a spatial period equal to the 413-nm wavelength of the pump photons, and with a visibility of 62% when the path-length difference exceeds the coherence length of the individual photon beams. This unequivocally demonstrates the nonclassical and entangled nature of the two-photon state.

Multiplexing of nonlinear fiber-optic interferometric sensors

The scheme is demonstrated with a three-sensor array consisting of magnetic-field, pressure, and displacement sensors exhibiting resolutions at 1 Hz of 20 mu Oe/ square root Hz (limited by ambient noise), 0.1 kPa/ square root Hz, and 30 nm/ square root Hz, respectively. Multiplexing is accomplished by dithering each transducer at a different frequency and using parallel phase-sensitive detectors (PSD) at the interferometer output to demultiplex the information. A single Mach-Zehnder interferometer driven by a single unmodulated laser was used. Factors affecting the performance of the multiplexing scheme, including interferometric demodulation technique, PSD performance, and nonlinear transduction mechanism, are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>