Hybrid Mach-Zehnder Interferometer Research Articles

Fabrication and characterization of electro-optic polymer/silicon hybrid MZI for interrogating small signals from an ECG

A Mach–Zehnder interferometer (MZI) composed of electro-optical polymer/silicon hybrid slot waveguides is reported. The device is designed to be asymmetrical so that the modulator is in a linear workspace when no electric field is applied to the initial operating state. We rely on the fast and strong nonlinearities of CLD-1/PMMA that infiltrates silicon rather than on the slower free-carrier effect in silicon. The modulated arm waveguides are designed in the shape of silicon/polymer hybrid slot waveguides to increase the interaction of the polymer material with the light field. The results show that the loss of the proposed MZI is 3.51 dB with a core size of 420μm × 160μm, and the half-wave voltage of the MZI is 2.1 V at 1550 nm, which provides the possibility of application in measuring small signals from an electrocardiogram with the optical principle.

A Selectable Single-Mode Erbium Fiber Laser With Mach-Zehnder Interferometer and Rayleigh Injection Scheme

In the paper, a hybrid Mach-Zehnder interferometer (MZI) and Rayleigh backscattering (RB) injection is designed and applied in the erbium-doped fiber (EDF) ring laser configuration. The MZI scheme and RB-induced signal can accomplish the single-longitudinal-mode (SLM) oscillation and narrow the linewidth to kHz target for each generated wavelength over the available wavelength-tuning bandwidth. In the measurement, the output power, optical signal to noise ratio (OSNR) and wavelength linewidth of the designed fiber laser are also executed and discussed.

Fabrication of Hybrid Mach-Zehnder Interferometer based on Hollow-Core Photonic Crystal Fiber for Load Measurement

Fabrication of Hybrid Mach-Zehnder Interferometer based on Hollow-Core Photonic Crystal Fiber for Load Measurement

Dispersed-Monolayer Graphene-Doped Polymer/Silica Hybrid Mach-Zehnder interferometer (MZI) Thermal Optical Switch with Low-Power Consumption and Fast Response.

This article demonstrates a dispersed-monolayer graphene-doped polymer/silica hybrid Mach–Zehnder interferometer (MZI) thermal optical switch with low-power consumption and fast response. The polymer/silica hybrid MZI structure reduces the power consumption of the device as a result of the large thermal optical coefficient of the polymer material. To further decrease the response time of the thermal optical switch device, a polymethyl methacrylate, doped with monolayer graphene as a cladding material, has been synthesized. Our study theoretically analyzed the thermal conductivity of composites using the Lewis–Nielsen model. The predicted thermal conductivity of the composites increased by 133.16% at a graphene volume fraction of 0.263 vol %, due to the large thermal conductivity of graphene. Measurements taken of the fabricated thermal optical switch exhibited a power consumption of 7.68 mW, a rise time of 40 μs, and a fall time of 80 μs at a wavelength of 1550 nm.

Polarization dependence of a graphene-optical fiber hybrid Mach-Zehnder interferometer.

Graphene exhibits a particular optical polarization dependence property, which is that supporting optical polarization states of graphene can be readily altered through tuning the polarity of the imaginary part of its conductivity. The in-fiber Mach-Zehnder interferometer (MZI) possesses extremely high sensitivity to the surrounding refractive index through cladding modes. Combining graphene and the in-fiber interferometer, a graphene-optical fiber hybrid MZI is constructed. Depending on the graphene polarization dependence property, the interference wavelength of the graphene-optical fiber hybrid MZI expresses periodic drift with the in-fiber light linear polarization angle adjusting within 180°. Meanwhile, drift periods corresponding to different interference wavelengths are slightly different, which is primarily due to the superposition of the polarization dependence behaviors of different cladding modes. For different light polarization states, with the in-fiber optical power increasing, the interference wavelengths and contrast intensities of the hybrid MZI transmission spectrum show a polarization independent linear blue shift and a nonlinear decrease, respectively.

Hybrid MZI-SOA InGaAs/InP Photonic Integrated Switches

A low-power, high-performance integrated 4 × 4 hybrid Mach–Zehnder interferometer (MZI) semiconductor optical amplifier (SOA) optical switch is designed, fabricated, and characterized. The 4 mm × 6 mm device is fabricated using an active–passive integration scheme in an InGaAsP/InP foundry. MZIs are implemented as the main switching elements and short switchable SOAs are used to either compensate the loss or suppress the crosstalk. A dilated Benes architecture is implemented to reduce the crosstalk and offer rearrangeably nonblocking connections. The 4 × 4 switch exhibits a low 1.3–dB loss, a crosstalk ratio of −47 dB, and more than 13–dB input power dynamic range (IPDR) for a 0.5–dB power penalty at a 10–Gb/s signal rate. By active control of injection currents into the SOAs, a fixed output power is achieved for a 10-dB range of input power and the IPDR is extended by at least 4 dB. A 12-mA control current tolerance has been demonstrated for a 10-dB IPDR. The performance of a 16 × 16 switch is emulated by cascading two 4 × 4 chips. A record IPDR of 15 dB at a 1-dB penalty is achieved with a 0.6–dB power penalty floor.

Low Latency Optical Switch for High Performance Computing With Minimized Processor Energy Load [Invited

Power density and cooling issues are limiting the performance of high performance chip multiprocessors (CMPs), and off-chip communications currently consume more than 20% of power for memory, coherence, PCI, and Ethernet links. Photonic transceivers integrated with CMPs are being developed to overcome these issues, potentially allowing low hop count switched connections between chips or data center servers. However, latency in setting up optical connections is critically important in all computing applications, and having transceivers integrated on the processor chip also pushes other network functions and their associated power consumption onto the chip. In this paper, we propose a low latency optical switch architecture that minimizes the power consumed on the processor chip for two scenarios: multiple-socket shared memory coherence networks and optical top-of-rack switches for data centers. The switch architecture reduces power consumed on the CMP using a control plane with a simplified send and forget server interface and the use of a hybrid Mach-Zehnder interferometer and semiconductor optical amplifier integrated optical switch with electronic buffering. Results show that the proposed architecture offers a 42% reduction in head latency at low loads compared with a conventional scheduled optical switch as well as offering increased performance for streaming and incast traffic patterns. Power dissipated on the server chip is shown to be reduced by more than 60% compared with a scheduled optical switch architecture with ring resonator switching.

Silicon-Organic Hybrid MZI Modulator Generating OOK, BPSK and 8-ASK Signals for Up to 84 Gbit/s

We report on high-speed multilevel signal generation and arbitrary pulse shaping with silicon-organic hybrid (SOH) Mach-Zehnder interferometer (MZI) modulators. Pure phase modulation exploiting the linear electrooptic effect allows the generation of multiple modulations formats at highest speed such as 40-Gbit/s on-off-keying (OOK) and binary-phase-shift keying (BPSK) and 28-Gbd 4-ASK and 8-ASK with data rates up to 84 Gbit/s. Additionally, beside NRZ pulse shaping, for the first time, Nyquist pulse shaping with silicon modulators is demonstrated to enable multiplexing at highest spectral efficiency.

Driving-Noise-Tolerant Broadband Polymer/Silica Hybrid Thermo-Optic Switch with Low Power Consumption

A polymer/silica hybrid Mach–Zehnder interferometer thermo-optic switch is experimentally demonstrated. The switch exhibits low power consumption of 7.8 mW, high extinction ratio of 32.6 dB, and short rise and fall times of 107 and 71 μs, respectively. The output spectrum is 50 nm (1,520–1,570 nm), with the extinction ratio level of over 18 dB. The driving-noise tolerance of this device was experimentally investigated by imposing a generated tunable noise on the pure driving signal. The device reveals a voltage-noise budget as high as 1.1 Vpp relative to a driving voltage of 3.0 Vpp for obtaining higher than a 10-dB extinction ratio.

Hybrid Mach–Zehnder interferometer and knot resonator based on silica microfibers

We propose and demonstrate an all-fiber high Q Mach–Zehnder interferometer (MZI)-coupled microknot resonator (MZKR) structure using optical microfibers drawn from silica fibers. The experimental results show that this microfiber-based structure achieved a high Q factor of ∼ 15,000 and good interference fringes with extinction ratio of up to ∼ 15 dB. By optimizing the loop-length of the microfiber knot and the optical path-difference of the MZI, the desired MZKR with higher Q factor and better extinction ratio could be obtained. A series of integrated all-fiber optical devices could be realized based on such a MZKR structure due to its outstanding advantages of easy fabrication, great flexibility, low cost, low loss, etc.

Hybrid MZI optical regeneration for XGM wavelength converter

We propose and experimentally demonstrate an optical 2R limiter circuit for improvement of cross gain modulation (XGM) wavelength converter performance. The 2R limiter circuit based on a hybrid Mach–Zehnder Interferometer provides a non-inverted output signal and an improved extinction ratio compared to the conventional XGM wavelength converted signal. The optimum operation condition of 2R limiter in terms of the gain and phase variations of linear optical amplifier (LOA) and semiconductor optical amplifier (SOA) is described.

Unrepeatered 160 Gbit/s RZ single-channel transmission over 160 km of standard fibre at 1.55 [micro sign]m with hybrid MZI optical demultiplexer

The authors report on single-channel, single-polarisation, 160 Gbit/s, RZ, 1.55 µm transmission over 160 km of standard fibre without inline optical amplifiers, with passive compensation of dispersion and dispersion slope, and using an optical 160 to 10 Gbit/s demultiplexer based on a hybrid Mach-Zehnder interferometer.

All-optical switching in a hybrid Mach–Zehnder interferometer as a result of cascaded second-order nonlinearity

We demonstrate, for the first time to our knowledge, all-optical switching with a contrast ratio of 7:1 based on the cascaded second-order nonlinearity. We performed the switching experiments in a nonlinear hybrid Mach–Zehnder interferometer, using a nonuniformly temperature-tuned lithium niobate channel waveguide in an operating regime of small fundamental depletion.