Standard Mach-Zehnder Interferometer Research Articles

Deterministic enhancement for bright-seeded Mach–Zehnder interferometer using low-noise feed-forward amplifiers

We propose to use low-noise feed-forward amplifiers (LFAs) to enhance the phase sensitivity of a bright-seeded Mach–Zehnder interferometer (MZI). LFAs are performed on the two arms inside the MZI, which are based entirely on linear optics, off-line squeezed ancillary states, and homodyne detectors. We demonstrate the necessity of LFA-based topology in achieving sensitivity improvement beyond the standard quantum limit, compared with the deterministic linear amplification scheme. Remarkably, we find that the LFA-based MZI is advantageous over the standard MZI in robustness against the internal losses of the interferometer.

Enhanced on-chip phase measurement by inverse weak value amplification

Optical interferometry plays an essential role in precision metrology such as in gravitational wave detection, gyroscopes, and environmental sensing. Weak value amplification enables reaching the shot-noise-limit of sensitivity, which is difficult for most optical sensors, by amplifying the interferometric signal without amplifying certain technical noises. We implement a generalized form of weak value amplification on an integrated photonic platform with a multi-mode interferometer. Our results pave the way for a more sensitive, robust, and compact platform for measuring phase, which can be adapted to fields such as coherent communications and the quantum domain. In this work, we show a 7 dB signal enhancement in our weak value device over a standard Mach-Zehnder interferometer with equal detected optical power, as well as frequency measurements with 2 kHz sensitivity by adding a ring resonator.

Nonlinear phase estimation enhanced by an actively correlated Mach-Zehnder interferometer

A nonlinear phase shift is introduced to a Mach-Zehnder interferometer (MZI), and we present a scheme for enhancing the phase sensitivity. In our scheme, one input port of a standard MZI is injected with a coherent state and the other input port is injected with one mode of a two-mode squeezed-vacuum state. The final interference output of the MZI is detected with the method of active correlation output readout. Based on the optimal splitting ratio of beam splitters, the phase sensitivity can beat the standard quantum limit and approach the quantum Cram\'{e}r-Rao bound. The effects of photon loss on phase sensitivity are discussed. Our scheme can also provide some estimates for units of $\chi^{(3)}$, due to the relation between the nonlinear phase shift and the susceptibility $\chi^{(3)}$ of the Kerr medium.

Measuring the gravitational acceleration with matter-wave velocimetry

One of the major limitations of atomic gravimeters is represented by the vibration noise of the measurement platform, which cannot be distinguished from the relevant acceleration signal. We demonstrate a new method to perform an atom interferometry measurement of the gravitational acceleration without any need for a vibration isolation system or post-corrections based on seismometer data monitoring the residual accelerations at the sensor head. With two subsequent Ramsey interferometers, we measure the velocity variation of freely falling cold atom samples, thus determining the gravitational acceleration experienced by them. Our instrument has a fractional stability of $ 9 \times 10^{-6}$ at 1 s of integration time, one order of magnitude better than a standard Mach-Zehnder interferometer when operated without any vibration isolation or applied post-correction. Using this technique, we measure the gravitational acceleration in our laboratory, which is found in good agreement with a previous determination obtained with a FG5 mechanical gravimeter.

Spectral detection of graphene and graphene oxide with SU-8 based asymmetry tripled-Arm Mach Zehnder

This paper reports the experimental application of the fabricated SU-8 based triple arm Mach-Zehnder interferometer (MZI) in the detection of graphene and graphene oxide. A standard MZI has two arms in its structure. In our design, we combine two MZIs with different dimensions together in a way that a short arm MZI replaces one longer arm of the larger MZI. The parallel connections of the two MZIs with a common arm would enhance the overall sensitivity of the sensor. The measurands graphene and graphene oxide with almost similar refractivity has been applied to sensing arms of the MZI in separate steps. The equidistance picometric spectral shifts corresponding to each measurands over the operating wavelength of 1550nm are observed and is suitable for detection of graphene and graphene oxide.

Weak-measurement Mach-Zehnder interferometer for testing wave-particle duality

The Mach-Zehnder interferometer (MZI) is a regular yet simple instrument to test wave-particle duality. One key device in a standard MZI is the beam splitter 2 (BS2). Here we make a simple quantum mechanics analysis about the wave function evolution and find that the strong and exclusive interaction of BS2 with the incident microscopic particle beam (photons, electrons, etc.) is the fundamental reason why standard MZIs could not allow for the simultaneous observation of wave and particle properties of these particles. A weak-measurement (WM) MZI setup is then proposed, where BS2 is replaced with a deliberately designed highly transparent interference screen operating via either weak absorption or weak-scattering effect. Quantum-mechanical analysis on this WM-MZI shows that the overall power to make simultaneous observation of interference fringe (wave nature) and which-path information (particle nature) of microscopic particles can be significantly enhanced compared with the standard MZIs.

Tunable multi-wavelength erbium-doped fiber laser by cascading a standard Mach–Zehnder interferometer and a twin-core fiber-based filter

A tunable multi-wavelength erbium-doped fiber laser (MEDFL) based on a nonlinear optical loop mirror (NOLM) was proposed and experimentally demonstrated by cascading a standard Mach–Zehnder interferometer (MZI) and a twin-core fiber (TCF)-based filter. Due to the ‘blue shift’ of the transmission band of the TCF-based filter when the TCF was bent, a tunable lasing waveband was realized by moving the transmission band of the TCF-based filter to cover different channels provided by the standard MZI. Experimental results showed that the lasing waveband can be linearly tuned over a range of 24 nm from 1542 to 1566 nm with a channel spacing of 0.4 nm, a maximum lasing line amount of 19, and an optical signal to noise ratio (OSNR) of 39 dB. The stability of the laser spectra was verified with a wavelength drift of 0.04 nm and a power fluctuation of ±0.3 dB.

Analytical model, analysis and parameter optimization of a super linear electro-optic modulator (SFDR > 130 dB)

An analytical model of a super linear optical modulator with high spurious-free-dynamic-range (SFDR > 130 dB) is presented and analyzed. The linear modulator is referred to as IMPACC which stands for Interferometric Modulator with Phase-modulating And Cavity-modulating Components. The modulator is based on a unique combination of a RF-driven phase-modulator (PM) and a ring resonator (RR) within a Mach–Zehnder interferometer (MZI) configuration. Our analysis shows that our design can achieve SFDR values which are ~ 20 dB higher than the standard MZI modulator and 3–5 dB from the Ring Assisted Mach-Zehnder Interferometer (RAMZI) modulator. Both PM and RR in the IMPACC are simultaneously driven by a RF signal of the same frequency, but not necessarily the same amplitudes. The analytical model shows that the combination of these two optical elements, with the proper choice of RF-driving and device parameters, can lead to four important and compelling consequences. First, it offers a wholistic and elegant model in which the standard MZI modulator and the RAMZI modulator are just special cases of IMPACC. Second, the model offers an excellent parameter optimization methodology for fast parameter (internal and/or external) selection and performance evaluation. Third, it provides additional degree of control through the introduction of an external control parameter, the RF power split ratio ( F). Lastly, it demonstrates one unique feature of IMPACC such as adaptive SFDR characteristics, where manufacturing tolerances in the transmission coefficient ( τ) of the RR can be compensated with proper adjustments of the external parameter of the power split ratio ( F).

Large Signal Analysis of the Mach-Zehnder Interferometer with One Arm Loaded with a Second-Order Allpass Double-Microring Resonator

A mathematical model for the transfer function of the Mach-Zehnder interferometer with one arm loaded with a second-order allpass double-microring resonator (2R-MZI) is presented. The model, basically a sine-series function, can easily yield closed-form expressions for the amplitudes of the harmonic and intermodulation components of the output when the input is formed of large-amplitude multisinusoidal RF voltage. The special case of two-tone equal-amplitude RF input voltage is considered in detail. The results show that the third-order intermodulation component is always higher than the third-harmonic component. The results also show the extensive improvement in the linearity of the Mach-Zehnder interferometer with one arm loaded with a second-order allpass microring resonator. Compared with the standard Mach-Zehnder interferometer, the results show that a sharp reduction of 80 dB in the third-order intermodulation can be achieved.

Confronting the complementarity principle in an interference experiment

We propose a variant of the standard Mach-Zehnder interferometer experiment which is predicted by the formalism of quantum optics to display unambiguous particle-like and wave-like propagation of “single photon states” under identical conditions, confronting the complementarity principle it also clarifies certain issues involved in the interpretations of the QM formalism.