Modified Mach-Zehnder Interferometer Research Articles

Synthesis and optical properties of fluorinated polyurethaneimide electro-optic waveguide polymer

Fluorinated polyurethaneimide (PUI) electro-optic waveguide polymer with polyurethane and polyimide chain segment structures was synthesized by stepwise polymerization using the synthesized amino ester oligomer pu and imide oligomer pi as monomers. Since the main chain structure of the synthesized PUI had the functionality of both polyurethane and polyimide chain segment structures, it combines the excellent thermal and film-forming properties of polyurethanes and polyimides, as well as lower optical transmission loss in the near-infrared wavelength band. The glass transition temperature (Tg) of PUI was 182 °C, and the 5% heat loss decomposition temperature was 325 °C. The PUI had good optical properties with an optical propagation loss of 1.10 dB/cm and an electro-optic (EO) coefficient (γ33) of 86 pm/V at a wavelength of 1550 nm. A Mach-Zehnder interferometric polymer waveguide EO modulator had been designed and fabricated by using the PUI as a waveguide electro-optic core layer. The prepared polymer waveguide EO modulator showed a good electro-optic modulation response at a wavelength of 1550 nm under an applied 1 kHz sinusoidal modulation signal. The results showed that the synthesized PUI met the performance requirements for the preparation of polymer optical waveguide devices and was a polymer electro-optic waveguide material with good overall performance.

Quantum dot fourth-harmonic colliding pulse mode-locked laser for high-power optical comb generation

Quantum-dot mode-locked lasers have advantages such as high temperature stability, large optical bandwidth, and low power consumption, which make them ideal optical comb sources, especially for wavelength-division multiplexing (WDM) telecommunications, and optical I/O applications. In this work, we demonstrate an O-band quantum dot colliding pulse mode-locked laser (QD-CPML) to generate optical frequency combs with 200 GHz spacing with maximum channels of 12 within 3 dB optical bandwidth. To achieve the high output power of individual comb lines, four channel conditions are implemented at central wavelength of 1310 nm for WDM transmission experiments. Each channel exhibits more than 10 dBm output power with 200 Gb/s PAM-4 and 270 Gb/s PAM-8 modulation capability via thin-film LiNbO3 Mach–Zehnder interferometer modulator without the requirement of any optical amplifications. This high-order QD-CPML is an ideal comb source for power-efficient optical interconnects and large bandwidth optical data transmission.

Chip-scale all-optical complex-valued matrix inverter

Matrix inversion is a fundamental and widely utilized linear algebraic operation but computationally expensive in digital-clock-based platforms. Optical computing is a new computing paradigm with high speed and energy efficiency, and the computation can be realized through light propagation. However, there is a scarcity of experimentally implemented matrix inverters that exhibit both high integration density and the capability to perform complex-valued operations in existing optical systems. For the first time, we experimentally demonstrated an iterative all-optical chip-scale processor to perform the computation of complex-valued matrix inversion using the Richardson method. Our chip-scale processor achieves an iteration speed of 10 GHz, which can facilitate ultra-fast matrix inversion with the assistance of high-speed Mach–Zehnder interferometer modulators. The convergence can be attained within 20 iterations, yielding an accuracy of 90%. The proposed chip-scale all-optical complex-valued matrix inverter represents a distinctive innovation in the field of all-optical recursive systems, offering significant potential for solving computationally intensive mathematical problems.

Determining Topological Charge of Bessel-Gaussian Beams Using Modified Mach-Zehnder Interferometer

The orbital angular momentum (OAM) associated with structured singular beams carries vital information crucial for studying various properties and applications of light. Determining OAM through the interference of light is an efficient method. The interferogram serves as a valuable tool for analyzing the wavefront of structured beams, especially identifying the order of singularity. In this study, we propose a modified Mach–Zehnder interferometer architecture to effectively determine the topological charge of Bessel–Gaussian (BG) beams. Several numerically generated self-referenced interferograms have been used for analysis. Moreover, this study examines the propagation property and phase distribution within BG beams after they are obstructed by an aperture in the interferometer setup.

On the Time-Dilation Paradox—Can it be Removed?

In special relativity theory, the velocity of light is assumed to be constant, independent of the reference frame. This creates paradoxes when observations in different reference frames are compared. The so-called twin-paradox is based on a Gedanken experiment with identical twins, one traveling in a spaceship and one remaining on Earth. Due to the time-dilation effect, the traveling twin, when returning to Earth is younger than the other twin. This paradox has been tentatively resolved by inserting asymmetry, but the fully symmetrical twin-paradox remains within the relativity theory. However, if the light velocity, instead of being absolute, is taken to be relative, the paradox can be resolved. By reevaluating the light-clock experiment and performing various other Gedanken experiments, it becomes apparent that constant movement, independent of velocity, is the same as “at rest” for any one reference frame and does not need to involve any relativistic effects. This would make the Lorentz–Voigt factor void, and red- and blue-shifts of electromagnetic (EM) radiation can be explained as true changes in light-velocities. Based on thinking experiments, new rules for light-velocities are proposed, which also could explain anomalous observations regarding Jupiter’s moon Io’s movement. Gravity and its effect on light are examined, and it is argued that planetary lensing of light can be simply explained as refraction in a planet’s atmosphere or by diffraction on the planet itself. Further, the light pressure can resolve the indistinguishability principle. Alternatives to relativity explanations are suggested for several observations that nullify Fresnel dragging and oppose the existence of an aether medium. A modified Mach–Zehnder interferometer is proposed as an instrument for measuring sub-c and super-c velocities of EM-waves. The “old” relativity theories are replaced by a novel postulate that an applied force, leading to changes in velocity, is the reason for time-dilation: what may be called mechanical relativity. A mathematical suggestion of mechanical relativity is presented, along with discussions on connections between time, energy, and gravity.

Enabling secure high-speed data transmission: Coherent chaotic optical communication with deep learning and electro-optic feedback

Coherent chaotic optical communication represents a present-day technique for attaining excessive-pace, long-distance statistics transmission with first-rate protection. This approach combines deep-gaining knowledge of chaotic synchronization (DLM-CS) models with virtual-sign processing algorithms to counteract fibre transmission impairments, resulting in a sturdy and green communiqu? device. Chaotic indicators are generated through electro-optic feedback, explicitly using Optical Intensity Chaos and Optical Phase Chaos (OIC), facilitated by Mach-Zehnder Modulator and Interferometer (MZM/MZI) modulators. Additionally, device getting to know-primarily based algorithms are hired to mitigate non-linearity in the communiqu? channel. Performance analysis in this context encompasses Bit Error Rate(BER), lengthy-distance communication competencies, chaotic signal periodicity, chaos synchronization, and safety. This technique allows for steady, high-speed facts transmission over prolonged distances, making it an important era for numerous packages, which includes telecommunications and statistics safety.

Geometric phase for investigation of nanostructures in approaches of polarization-sensitive optical coherence tomography

Proposed paper presents the latest results in the framework of polarization-sensitive low-coherence interferometry related to new approaches for using the geometric phase to reproduce the polarization structure of a biological transparent anisotropic micro (nano) object. The polarization parameters of an anisotropic object are measured in real time on the basis of a modified Mach-Zehnder interferometer. The advantage of using the geometric phase is the diagnostic of polarization anisotropic surface (subsurface) nanosized layers in a non-contact, non-invasive manner.

Modeling of the high-resolution optical-coherence diagnostics of bi-refringent biological tissues

We present a computer model of the polarization-sensitive interference diagnostics of the bi-refringent biological media, with a particular example of the lamella of eye cornea. The diagnostic procedure employs the modified Mach–Zehnder interferometer with controllable phase retardation of the reference wave, separate observation of the orthogonal linearly-polarized interference signals, and evaluation of the phases and amplitudes of their variable (AC) components. The data obtained permit to determine the mean refractive index as well as the difference between the extraordinary and ordinary refractive indices, which, in turn, indicates the optical axis and the collagen fibers’ orientation in the lamella. The modelled procedure enables the sample structure diagnostics with the longitudinal and lateral resolution ∼100 nm and ∼1.8 μm, correspondingly. In particular, it permits a reliable detection and quantitative characterization of a thin (<100 nm) near-surface layer where the mean refractive index differs by less than 1% from that in the main volume (due to the different orientation of the collagen fibers). The diagnostic approach, developed in the paper, can be useful in various problems of structure characterization of optically-anisotropic biological tissues.

Synthesis and Characterization of Electro-Optic Polyurethaneimide-Polyimide Copolymers

Polyurethaneimide prepolymer was synthesized using the synthesized chromophore C containing tricyanofuran, hexafluorodianhydride and phenyl diisocyanate as monomers. Polyimide prepolymers were synthesized using fluorinated aromatic diether dianhydride and fluorinated aromatic diamine as monomers. Polyurethaneimide-polyimide (PUI-FPI) copolymers were then synthesized by a polycondensation reaction of the polyimide and polyurethaneimide prepolymers. The electro-optic (EO) PUI-FPI copolymers had a special segment structure and concentrate the advantages of polyurethaneimide and polyimide. The copolymers exhibited good film-forming properties, high glass transition temperature (Tg =196 °C), and high thermal stability (Td up to 358 °C). The copolymers possessed a high EO coefficient (γ33 =72 pm/V) at the 1550 nm wavelength, good long-term electro-poled orientation stability, and low optical propagation loss (1.2–1.4 dB/cm) at 1550 nm. Mach-Zehnder interferometric electro-optic modulators were designed and fabricated using the synthesized copolymer as the waveguide material. The prepared polymer optical waveguide EO modulators showed a good low-frequency electro-optic modulation response. The results showed that the synthesized polyurethaneimide-polyimide copolymers meeted the performance requirements for the preparation of polymeric optical waveguide devices and were suitable as polymeric electro-optic waveguide materials.

Modified Mach-Zehnder interferometer for spatial coherence measurement.

Spatial coherence of light sources is usually obtained by using the classical Young's interferometer. Although the original experiment was improved upon in successive works, some drawbacks still remain. For example, several pairs of points must be used to obtain the complex coherence degree (normalized first-order correlation function) of the source. In this work, a modified Mach-Zehnder interferometer which includes a pair of lenses and is able to measure the spatial coherence degree is presented. With this modified Mach-Zehnder interferometer, it is possible to measure the full 4D spatial coherence function by displacing the incoming beam laterally. To test it, we have measured only a 2D projection (zero shear) of the 4D spatial coherence, which is enough to characterize some types of sources. The setup has no movable parts, making it robust and portable. To test it, the two-dimensional spatial coherence of a high-speed laser with two cavities was measured for different pulse energy values. We observe from the experimental measurements that the complex degree of coherence changes with the selected output energy. Both laser cavities seem to have similar complex coherence degrees for the maximum energy, although it is not symmetrical. Thus, this analysis will allow us to determine the best configuration of the double-cavity laser for interferometric applications. Furthermore, the proposed approach can be applied to any other light sources.

An exploratory simulation study and prediction model on human brain behavior and activity using an integration of deep neural network and biosensor Rabi antenna

The plasmonic antenna probe is constructed using a silver rod embedded in a modified Mach-Zehnder interferometer (MZI) ad-drop filter. Rabi antennas are formed when space-time control reaches two levels of system oscillation and can be used as human brain sensor probes. Photonic neural networks are designed using brain-Rabi antenna communication, and transmissions are connected via neurons. Communication signals are carried by electron spin (up and down) and adjustable Rabi frequency. Hidden variables and deep brain signals can be obtained by external detection. A Rabi antenna has been developed by simulation using computer simulation technology (CST) software. Additionally, a communication device has been developed that uses the Optiwave program with Finite-Difference Time-Domain (OptiFDTD). The output signal is plotted using the MATLAB program with the parameters of the OptiFDTD simulation results. The proposed antenna oscillates in the frequency range of 192 THz to 202 THz with a maximum gain of 22.4 dBi. The sensitivity of the sensor is calculated along with the result of electron spin and applied to form a human brain connection. Moreover, intelligent machine learning algorithms are proposed to identify high-quality transmissions and predict the behavior of transmissions in the near future. During the process, a root mean square error (RMSE) of 2.3332(±0.2338) was obtained. Finally, it can be said that our proposed model can efficiently predict human mind, thoughts, behavior as well as action/reaction, which can be greatly helpful in the diagnosis of various neuro-degenerative/psychological diseases (such as Alzheimer's, dementia, etc.) and for security purposes.

High-efficiency thin-film lithium niobate modulator with highly confined optical modes.

We demonstrate a low-loss, high-efficiency lithium niobate electro-optic (EO) modulator with optical isolation trenches to achieve stronger field confinement and reduced light absorption loss. The proposed modulator realized considerable improvements, including a low half-wave voltage-length product of 1.2 V·cm, an excess loss of ∼2.4 dB, and a broad 3-dB EO bandwidth of over 40 GHz. We developed a lithium niobate modulator with, to the best of our knowledge, the highest reported modulation efficiency of any Mach-Zehnder interferometer (MZI) modulator.

Increasing Measurements Range of Electro-Optic Sensors for Electric Field by Using a Mach–Zehnder Interferometer Modulators Array

Increasing Measurements Range of Electro-Optic Sensors for Electric Field by Using a Mach–Zehnder Interferometer Modulators Array

Refractive index profile measurement of planar optical waveguides based on the near-field technique and digital holography

• A new method is proposed to measure the refractive index profile of planar optical waveguides. • A measurement system is established by integrating the near-field setup and the modified Mach-Zehnder interferometer. • The refractive index profile is quantitatively obtained from two phase difference distributions. • The accuracy of the proposed method is up to 1 × 10 −3 . A method based on the near-field technique and digital holography is proposed to measure the refractive index profile of planar optical waveguides. A measurement system is established by integrating the near-field setup and the modified Mach-Zehnder interferometer. The near-field intensity profile of optical waveguides is recorded by CCD to get the primary refractive index profile. The primary phase difference distribution is calculated based on the relationship between the phase and refractive index. The digital hologram is acquired by the modified Mach-Zehnder interferometer to extract the real phase difference distribution using the hybrid reconstruction algorithm. According to the relationship between the primary and real phase difference distributions, the refractive index profile is quantitatively obtained. To evaluate the proposed method, we measured the refractive index profiles of multimode and single-mode fibers and compared with S14 based on refracted near-field method and SHR-1802 based on digital holography. The proposed method has a measurement accuracy of up to 1 × 10 -3 and is suitable for measuring the positive refractive index region of waveguides.

Calibration of the Soleil–Babinet Compensator Based on the Vectorial Optical Field

The Soleil–Babinet compensator (SBC) is a variable retarder and has been used in a variety of application fields. A scheme based on the vectorial optical field is proposed to calibrate the SBC by transforming the change of the phase retardation into the visible rotation of the petal-like pattern. The relationship between the rotation angle of the petal-like pattern and the phase retardation of the SBC is established theoretically. In the experiment, the vector beam is generated by using the spiral phase plate (SPP) and the modified Mach–Zehnder interferometer based on the superposition principle of two orthogonal circularly polarized vortex beams with opposite topological charges. Taking advantage of the image processing method, the rotation angles of the acquired petal patterns are calculated, and the relationship between the phase retardation of the SBC and the displacements of its micrometer screw is determined. The measured phase retardation of the SBC ranges from −277.00° to 516.57°. By linearly fitting the experimental data, the phase sensitivity is 33.076 ± 0.147 °/mm, and the coefficient of determination value that shows the linearity of the experimental data is 0.9995. The experimental results agree well with the theoretical data.

Phase-shifting hiding technology for fully phase-based image using the Mach–Zehnder interferometer

A two-step phase-shifting hiding technique for a fully phase-based image is proposed. A reference beam was generated with a laser illuminating the host image using our modified Mach–Zehnder interferometer (MZI) design, and an object beam was injected into a fully phase-based image that is to be hidden. A reference beam was used to engage the image-hiding function while providing phase changes in the hologram recording process. After Fresnel diffraction occurred on the two paths of the MZI, the diffracted waves were detected as interference patterns on a charge-coupled device plane, which resembled the host image’s Fresnel diffraction pattern. A theoretical analysis is provided alongside the experimental results.

Imaging inspired characterization of single photons carrying orbital angular momentum

We report on an imaging-inspired measurement of orbital angular momentum (OAM) using only a simple tilted lens and an intensified charged coupled device camera, allowing us to monitor the propagation of OAM structured photons over distance, which is crucial for free-space quantum communication networks. We demonstrate the measurement of OAM orders as high as ls = 14 in a heralded single-photon source and show, for the first time, the imaged self-interference of photons carrying OAM in a modified Mach–Zehnder interferometer. The described methods reveal both the charge and order of a photon's OAM and provide a proof of concept for the interference of a single OAM photon with itself. Using these tools, we are able to study the propagation characteristics of OAM photons over a distance, which is important for estimating transport in free-space quantum links. By translating these classical tools into the quantum domain, we offer a robust and direct approach for the complete characterization of a twisted single-photon source, an important building block of a quantum network.

Control of nonlinear processes using versatile random photonic sources: Application to the energy deposition in a dielectric material

We report on the properties of a nonconventional stochastic photonic source. We first describe the principle of nonlinear intensity filtering by using a modified Mach-Zehnder interferometer. The latter alters the characteristics of an input stochastic source based on Bose-Einstein emission. Computed output intensity fluctuations are compared to an analytical model. Adjusting the interferometer parameters, we show theoretically and numerically that the statistical properties of light such as its probability density function can be tailored. Depending on the parameters, the probability density may exhibit large overshoots or smoother fluctuations. We further evaluate the impact of these modified statistics on simple nonlinear processes. Compared to Bose-Einstein emitters, the yield of nonlinear phenomena varies by several orders of magnitude. We finally simulate the nonlinear interaction of such a laser source with a dielectric material (fused silica) within the framework of a more realistic model, including a statistical analysis. It confirms that the deposited energy varies over many decades and can be largely enhanced due to the properties of the presented laser source.

Efficient silicon and side-cladding waveguide modulator with electro-optic polymer.

Efficient electro-optic (EO) modulation can be generated in the hybrid silicon modulator with EO polymer in the form of an in-plane coplanar waveguide and electrode structure. Strong confinement of the optical field in the hybrid structure is critical to performing efficient electric poling and modulation of the EO polymer. The waveguide consists of silica-based side claddings and an EO core for increasing the integral of the optical field and the overlap interaction between the optical field and the modulated electric field within the EO polymer. We discuss in detail the volume resistivity dependence of the efficiency of electric poling and modulation for various side-cladding materials. In a Mach-Zehnder interferometer modulator, the measured half-wave-voltage length product (VπL) is 1.9 V·cm at an optical communication wavelength of 1,550 nm under the TE optical mode operation. The high-speed signaling of the device is demonstrated by generating on-off-keying transmission at signal rates up to 52 Gbit/s with a Q factor of 6.1 at a drive voltage of 2.0 Vpp.

Balloon-like angle and micro-displacement sensor based on bent single-mode fiber

In this paper, a simple balloon-like fiber sensing system based on a Mach-Zehnder modal interferometer by bending single-mode fiber (SMF) into a balloon-like structure is proposed, and the experiment proves that the system can be used for angle and micro-displacement measurement. The sensor system is only composed of SMF. Firstly, the transmission spectrum curves under different sensitive lengths and bending diameters are analyzed. It is found that the maximum extinction ratio of 24 dB can be achieved when the bending diameter of SMF is 8 mm. Then, by comparing the angle and micro-displacement sensitivity under different sensitivity lengths, it is found that the angle and micro-displacement sensitivity of balloon-like structures increase with the increase of sensitivity lengths. The angle measurement sensitivity is 253.1 pm/°, the detection range is −90° ∼ 90°, and the micro-displacement measurement sensitivity is 327.4 pm/μm. This sensor system has a great potential in the field of angle and micro-displacement measurement, and provides a new idea for angle and micro-displacement measurement.