Showing papers on "Mach–Zehnder interferometer published in 2011"
TL;DR: A high-temperature sensor based on a Mach-Zehnder interferometer (MZI) in a conventional single-mode optical fiber is proposed and fabricated by concatenating two microcavities separated by a middle section.
Abstract: A high-temperature sensor based on a Mach–Zehnder interferometer (MZI) in a conventional single-mode optical fiber is proposed and fabricated by concatenating two microcavities separated by a middle section A femtosecond laser is used to fabricate a microhole on the center of a fiber end Then a micro-air-cavity is formed by splicing the microholed fiber end with a normal fiber end The interferometer is applied for high-temperature sensing, in the range of 500–1200 °C, with a sensitivity of 109 pm/°C that, to the best of our knowledge, is highest in silica fiber temperature sensors Also, the interferometer is insensitive to external refractive index (RI), which is desirable for temperature sensors
186 citations
TL;DR: In this article, the authors constructed an interferometer with parametric amplifiers as beam splitters, and they found that the fringe intensity depends quadratically on the intensity of the phase sensing field at high gain.
Abstract: We construct an interferometer with parametric amplifiers as beam splitters. Because of the gain in the parametric amplifiers, the maximum output intensity of the interferometer can be much bigger than the input intensity as well as the intensity inside the interferometer (the phase sensing intensity). We find that the fringe intensity depends quadratically on the intensity of the phase sensing field at high gain. This type of nonlinear interferometer has better sensitivity than the traditional linear interferometer made of beam splitters with the same phase sensing intensity.
170 citations
TL;DR: In this article, a plasmonic Mach-Zehnder interferometer (MZI) is integrated with a microfluidic chip for ultrasound biosensing, which is formed by patterning two parallel nanoslits in a thin metal film, and the sensor monitors the phase difference, induced by surface biomolecular adsorptions, between surface Plasmon waves propagating on top and bottom surfaces of the metal film.
Abstract: We experimentally demonstrate a plasmonic Mach–Zehnder interferometer (MZI) integrated with a microfluidic chip for ultrasensitive optical biosensing. The MZI is formed by patterning two parallel nanoslits in a thin metal film, and the sensor monitors the phase difference, induced by surface biomolecular adsorptions, between surface plasmon waves propagating on top and bottom surfaces of the metal film. The combination of a nanoplasmonic architecture and sensitive interferometric techniques in this compact sensing platform yields enhanced refractive index sensitivities greater than 3500 nm/RIU and record high sensing figures of merit exceeding 200 in the visible region, greatly surpassing those of previous plasmonic sensors and still hold potential for further improvement through optimization of the device structure. We demonstrate real-time, label-free, quantitative monitoring of streptavidin–biotin specific binding with high signal-to-noise ratio in this simple, ultrasensitive, and miniaturized plasmoni...
154 citations
TL;DR: In this article, an all-fiber high-sensitivity temperature fiber sensor based on a Mach-Zehnder interferometer in standard single-mode fibers (SMFs) is described.
Abstract: An all-fiber high-sensitivity temperature fiber sensor based on a Mach-Zehnder interferometer in standard single-mode fibers (SMFs) is described. The interferometer consists of two concatenated waist-enlarged fusion bitapers which are fabricated simply by cleaving and fusion splicing. It is demonstrated that such an all-fiber Mach-Zehnder interferometer incorporates intermodal interference between the LP01 mode and a high-order cladding mode of LP07 mode. Its response to temperature is investigated and a high sensitivity of 0.070 nm/°C is obtained by a 7.5 mm interferometer. This simple, low-cost and easy-to-fabricate core-cladding modal interferometer with entire SMF-based structure also has great potential in diverse sensing applications.
153 citations
TL;DR: A highly sensitive refractive index (RI) sensor based on three cascaded single-mode fiber tapers, in which a weak taper is sandwiched between the two tapers to improve the sensitivity of the sensor.
Abstract: We report a highly sensitive refractive index (RI) sensor based on three cascaded single-mode fiber tapers, in which a weak taper is sandwiched between the two tapers to improve the sensitivity of the sensor. Experimental results show that the sensitivity of the device is 0.286 nm for a 0.01 RI change, which is about four times higher than that of the normal two-cascaded-taper-based Mach–Zehnder interferometer. In addition, the sensitivity of the device could be enhanced by tapering a longer and thinner middle weak taper. Such kinds of low-cost and highly sensitive fiber-optic RI sensors would find applications in chemical or biochemical sensing fields.
144 citations
Metz1
TL;DR: In this paper, the authors discuss and analyze the different sources of the drift in commercially LiNbO3 Mach-Zehnder modulators, and point out the predominant role of the intrinsic (dc) drift.
Abstract: The drift issue induces slow drifting of the optimum operating point for high efficiency or large nonlinearities in analog optical links, and requires complex control of the offset bias voltage for achieving high extinction ratio in digital optical links. We discuss and analyze the different sources of the drift in commercially LiNbO3 Mach-Zehnder modulators. The different extrinsic and intrinsic origins are compared in terms of phase shift and the different corresponding orders of magnitude are given, pointing out the predominant role of the intrinsic (dc) drift. We show the large role played by the electrical inhomogeneities at the surface of the LiNbO3 substrate by highlighting the link between the time dependence of the dc drift and the electrical conductivity measured at the surface and in the volume of the LiNbO3 substrate. This allows to propose a solution to the drift issue which consists in the engineering of the electrical conductivity of the lithium niobate substrate.
127 citations
TL;DR: In this paper, an optical fiber bend sensor with photonic crystal fiber (PCF) based Mach-Zehnder interferometer (MZI) is demonstrated experimentally.
117 citations
TL;DR: The proposed MZIs have lower temperature sensitivities compared with normal fiber sensors, which is a desirable merit for RI sensors to reduce the cross sensitivity caused by thermal drift.
Abstract: A taper-based Mach–Zehnder interferometer (MZI) embedded in a thinned optical fiber is demonstrated as a highly sensitive refractive index (RI) sensor. A RI sensitivity of 2210.84 nm/RIU (refractive index unit) is obtained at the external RI of 1.40, which is ten times higher than that of normal taper- and long-period fiber grating (LPFG)-based sensors. The sensitivity can be further improved by decreasing the diameter of the thinned fiber and increasing the interferometer length of the MZI. The proposed MZIs have lower temperature sensitivities compared with normal fiber sensors, which is a desirable merit for RI sensors to reduce the cross sensitivity caused by thermal drift.
95 citations
TL;DR: In this paper, a versatile, compact and sensitive in-fiber open cavity Mach-Zehnder interferometer (MZI) gas refractive index (RI) sensor formed by fusion splicing a short section of singlemode fiber (SMF) between two sections of single-mode fibers with a large intentional lateral offset is demonstrated.
Abstract: A versatile, compact and sensitive in-fiber open cavity Mach–Zehnder interferometer (MZI) gas refractive index (RI) sensor formed by fusion splicing a short section of single-mode fiber (SMF) between two sections of single-mode fibers with a large intentional lateral offset is demonstrated. The fabrication is easy, safe, and cost effective. Gas or other materials can contact with the light signal in the totally open cavity of sensor directly and easily, thus the ambient refractive index (RI) change can be detected very quickly. We discussed the fabrication and operation of the sensor, and we successfully used the sensor to monitor changes of refractive index of air as a function of pressure and obtained a sensitivity of over 3402 nm/RIU (refractive index unit) with good linearity and repeatability.
82 citations
TL;DR: The design enables a refractometer with a low limit of detection, low variability, and high sensitivity, comparable to state-of-the-art optofluidic refractometers that involve complex fabrication processes and/or expensive, bulky optics.
Abstract: We have developed a planar, optofluidic Mach–Zehnder interferometer for the label-free detection of liquid samples. In contrast to most on-chip interferometers which require complex fabrication, our design was realized via a simple, single-layer soft lithography fabrication process. In addition, a single-wavelength laser source and a silicon photodetector were the only optical equipment used for data collection. The device was calibrated using published data for the refractive index of calcium chloride (CaCl2) in solution, and the biosensing capabilities of the device were tested by detecting bovine serum albumin (BSA). Our design enables a refractometer with a low limit of detection (1.24 × 10−4 refractive index units (RIU)), low variability (1 × 10−4 RIU), and high sensitivity (927.88 oscillations per RIU). This performance is comparable to state-of-the-art optofluidic refractometers that involve complex fabrication processes and/or expensive, bulky optics. The advantages of our device (i.e. simple fabrication process, straightforward optical equipment, low cost, and high detection sensitivity) make it a promising candidate for future mass-producible, inexpensive, highly sensitive, label-free optical detection systems.
80 citations
TL;DR: In this paper, a technique based on the use of a Mach-Zehnder (MZ) interferometer is proposed to evaluate chirp properties, as well as the linewidth enhancement factor (αH-factor) of optoelectronic devices.
Abstract: In this paper, a technique based on the use of a Mach-Zehnder (MZ) interferometer is proposed to evaluate chirp properties, as well as the linewidth enhancement factor (αH-factor) of optoelectronic devices. When the device is modulated, this experimental setup allows the extraction of the component's response of amplitude modulation (AM) and frequency modulation (FM) that can be used to obtain the value of the αH-factor. As compared with other techniques, the proposed method gives also the sign of the αH-factor without requiring any fitting parameters and, thus, is a reliable tool, which can be used for the characterization of high-speed properties of semiconductor diode lasers and electroabsorption modulators. A comparison with the widely accepted fiber transfer function method is also performed with very good agreement.
TL;DR: In this paper, an optical liquid-level sensor (LLS) based on a long-period fiber grating (LPG) interferometer is proposed and experimentally demonstrated.
Abstract: An optical liquid-level sensor (LLS) based on a long-period fiber grating (LPG) interferometer is proposed and experimentally demonstrated. Two identical 3-dB LPGs are fabricated to form an in-fiber Mach-Zehnder interferometer, and the fiber portion between two LPGs is exposed to the liquid as the sensing element. The sensitivity and measurement range of the sensors employing different orders of cladding modes are investigated both theoretically and experimentally. The experimental results show good linearity and large measurement range. One of the significant advantages of such a sensing structure is that the measurement level is not limited to the length of the LPG itself. Also, the measurement range and sensitivity of the proposed LLS can be readily tailored for a particular applications.
TL;DR: In this paper, the authors proposed a methodology to measure the singleparticle coherence length from the decay of the Aharonov-Bohm oscillations as a function of the imbalance of a Mach-Zehnder interferometer.
Abstract: A unique type of electron source has emerged which permits to inject particles in a controllable manner, one at a time, into an electronic circuit. Such single-electron sources make it possible to address experimentally one of the most fundamental quantum properties of an electron, its coherence length. We propose a methodology to measure the single-particle coherence length from the decay of the Aharonov-Bohm oscillations as a function of the imbalance of a Mach-Zehnder interferometer.
TL;DR: In this article, an in-fiber Mach-Zehnder interferometer (MZI) was fabricated and characterized for solution refractive index (RI) sensors, which consists of two cascade double cladding fibers in a standard single mode fiber (SMF).
Abstract: An in-fiber Mach-Zehnder interferometer (MZI) was fabricated and characterized for solution refractive index (RI) sensors. The MZI consists of two cascade double cladding fibers (DCFs) in a standard single mode fiber (SMF). The DCFs serve as the in-fiber couplers which split and combine light propagating in the core and the outer cladding region. Since the cladding mode is excited, the interference spectrum is sensitive to the ambient RI variation. Within the RI range from 1.3333 to 1.4535, the sensor characteristics were characterized. The sensitivity of 31 nm/RIU and 823 nm/RIU were obtained for the lower RI (1.34) and the higher RI (1.44), respectively. With the mass-producing of DCF and the easy fabrication process of the sensor head, the proposed in-fiber MZI is a potential alternative for the RI sensor application.
TL;DR: The Mach-Zehnder interferometer as mentioned in this paper uses a Dove prism in each arm where each has a mirror plane around which the transverse phase profile is inverted, and it requires minimal angular alignment for the routing of beams carrying orbital angular momentum.
Abstract: We have developed an interferometer requiring only minimal angular alignment for the routing of beams carrying orbital angular momentum. The Mach–Zehnder interferometer contains a Dove prism in each arm where each has a mirror plane around which the transverse phase profile is inverted. One consequence of the inversions is that the interferometer needs no alignment. Instead the interferometer defines a unique axis about which the input beam must be coupled. Experimental results are presented for the fringe contrast, reaching a maximum value of 93±1%.
TL;DR: The development of a Mach-Zehnder interferometer biosensor based on a high index contrast polymer material system and the demonstration of label-free online measurement of biotin-streptavidin binding on the sensor surface are reported.
TL;DR: A fiber inline Mach-Zehnder interferometer (MZI) consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method, capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.
Abstract: A fiber inline Mach-Zehnder interferometer (MZI) consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method. By fusion-splicing, the taper diameter-length ratio is around 1:1, which is much greater than those (1:10) made by stretching. The proposed fabrication method is very low cost, 1/20–1/50 of those of LPFG pair MZI sensors. The fabricated MZIs are applied to measure refractive index, temperature and rotation angle changes. The temperature sensitivity of the MZI at a length of 30 mm is 0.061 nm/°C from 30–350 °C. The proposed MZI is also used to measure rotation angles ranging from 0° to 0.55°; the sensitivity is 54.98 nm/°. The refractive index sensitivity is improved by 3–5 fold by fabricating an inline micro–trench on the fiber cladding using a femtosecond laser. Acetone vapor of 50 ppm in N2 is tested by the MZI sensor coated with MFI–type zeolite thin film. The proposed MZI sensors are capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.
TL;DR: The experimental demonstration of ultrafast all-optical switching and wavelength down-conversion based on a novel nonlinear Mach-Zehnder interferometer with subwavelength grating and wire waveguides is reported on.
Abstract: We report on the experimental demonstration of ultrafast all-optical switching and wavelength down-conversion based on a novel nonlinear Mach-Zehnder interferometer with subwavelength grating and wire waveguides. Unlike other periodic waveguides such as line-defects in a 2D photonic crystal lattice, a subwavelength grating waveguide confines the light as a conventional index-guided structure and does not exhibit optically resonant behaviour. Since the device had no dedicated port to input optical signal to control switching a new approach was also implemented for all-optical switching control.
TL;DR: In this paper, an asymmetrical Mach-Zehnder Interferometer (MZI) structures on a submicrometer silicon-on-insulator platform are designed and analyzed when used as a polarization beam splitter (PBS).
Abstract: Asymmetrical Mach-Zehnder Interferometer (MZI) structures on a submicrometer silicon-on-insulator platform are designed and analyzed when used as a polarization beam splitter (PBS). The analysis shows that it is allowed to use 2×2 power splitter/combiner couplers with a balanced ratio (50:50) for only one polarization by selecting the output ports for TE and TM polarizations appropriately. This makes the design much easier and more flexible. Examples for the design of MZI-based PBSs using directional couplers as well as multimode interference couplers are given. Finally, compensating the positive or negative wavelength shifts due to fabrication errors is proposed by using a thermal-optical effect on the two MZI arms separately. The numerical calculation shows that a small temperature increase (e.g., 30°C) is enough to compensate the wavelength shift due to an arm-waveguide width deviation of 50 nm. The parameters of MZI arm waveguides are chosen appropriately in order to make the MZI wavelength shifts (due to the fabrication errors) almost polarization independent, so that the thermal compensation approach could push the central wavelengths for both polarizations back to the designed value.
15 May 2011
TL;DR: In this paper, a highly sensitive refractive-index sensor based on three cascaded single-mode fiber tapers is presented, in which a weak taper is sandwiched between the two tapers to improve the sensitivity of the sensor.
Abstract: We report the fabrication of a highly sensitive refractive-index sensor based on three cascaded single-mode fiber tapers,
in which a weak taper is sandwiched between the two tapers to improve the sensitivity of the sensor. Experimental
results show that the sensitivity of the device is 0.286 nm for a 0.01 RI change, which is about eleven times higher than
that of the normal two cascaded tapers MZ interferometer. Such kind of low-cost and highly sensitive fiber-optic
refractive index sensors will find applications in chemical or bio-chemical sensing fields.
TL;DR: In this article, the performances of all-optical logic gates XOR, AND, OR, NOR and NAND based on SOA have been simulated including the effects of amplified spontaneous emission (ASE).
TL;DR: In this paper, a ring-bus-ring (RBR) resonator system is proposed to generate a spectrum resembling electromagnetically induced transparency (EIT), which is qualitatively different compared to other existing EIT schemes.
Abstract: This paper presents theoretical studies on the ring-bus-ring (RBR) resonator system, which consist of two resonators indirectly coupled through a center waveguide between them. By controlling the intercavity interaction and engineering the phase response through incorporation of RBR with Mach-Zehnder interferometer, we show that it is possible to generate a spectrum resembling electromagnetically induced transparency (EIT), which is qualitatively different compared to other existing EIT schemes. The transparency becomes sharper as the coupling strength between resonators is increased, with the background spectrum significantly reduced as a result of additional phase shift from indirect coupling. In addition, the EIT-like spectrum is generated out of low-finesse resonators, in contrast with existing EIT schemes where the resonator's finesse is required to be high. Comparisons with finite-difference-time-domain simulation show fairly a good agreement with analytical formulations.
TL;DR: Stable and user-adjustable single-photon interference in a 1 km long fiber-optic Mach-Zehnder interferometer is experimentally demonstrated, using an active phase control system with the feedback provided by a classical laser.
Abstract: We experimentally demonstrate stable and user-adjustable single-photon interference in a 1 km long fiber- optical Mach-Zehnder interferometer, using an active phase control system with the feedback provided by a classical laser. We are able to continuously tune the single-photon phase difference between the interferometer arms using a phase modulator, which is synchronized with the gate window of the single-photon detectors. The phase control system employs a piezoelectric fiber stretcher to stabilize the phase drift in the interferometer. A single-photon net visibility of 0.97 is obtained, yielding future possibilities for experimental realizations of quantum repeaters in optical fibers, and violation of Bell's inequalities using genuine energy-time entanglement
TL;DR: High speed and high extinction ratio silicon optical modulator using carrier depletion is experimentally demonstrated using a 1.8 mm-long PIPIN diode integrated in a Mach Zehnder interferometer.
Abstract: High speed and high extinction ratio silicon optical modulator using carrier depletion is experimentally demonstrated. The phase-shifter is a 1.8 mm-long PIPIN diode which is integrated in a Mach Zehnder interferometer. 8.1 dB Extinction Ratio at 10 Gbit/s is obtained simultaneously with optical loss as low as 6 dB.
TL;DR: In this article, a tapered fiber Mach-Zehnder interferometer sensor is presented to simultaneously measure liquid level and temperature, and the level difference of 190mm can be measured with millimetre resolution in 90 mm-long linear range.
Abstract: A tapered fibre Mach-Zehnder interferometer sensor is presented to simultaneously measure liquid level and temperature. The transmission spectra shift with the change in immersed liquid level and environmental temperature. The liquid level difference of 190 mm can be measured with millimetre resolution in 90 mm-long linear range. The temperature response is discriminated from level response by simultaneously monitoring different interference orders at 1520 and 1620 nm. Level sensitivities of −0.017 and −0.021 nm/mm, and temperature sensitivities of 0.074 and 0.081 nm/°C are achieved, respectively.
TL;DR: In this article, the authors theoretically analyze a Mach-Zehnder interferometer with trapped condensates and find that it is surprisingly stable against the nonlinearity induced by interparticle interactions.
Abstract: We theoretically analyze a Mach-Zehnder interferometer with trapped condensates and find that it is surprisingly stable against the nonlinearity induced by interparticle interactions. The phase sensitivity, which we study for number-squeezed input states, can overcome the shot noise limit and be increased up to the Heisenberg limit provided that a Bayesian or maximum-likelihood phase estimation strategy is used. We finally demonstrate the robustness of the Mach-Zehnder interferometer in the presence of interactions against condensate oscillations and a realistic atom-counting error.
TL;DR: An experimental system consisting of a Dove prism embedded Mach-Zehnder (M-Z) interferometer and two gratings was built to sort and detect orbital angular momentum (OAM) states of light beams as discussed by the authors.
TL;DR: A femtosecond laser microfabricated fiber Mach-Zehnder interferometer is demonstrated and the dependences of the sensitivities of different environmental parameters on the specifications of the interferometers are revealed.
Abstract: We demonstrate a femtosecond laser microfabricated fiber Mach–Zehnder interferometer and reveal the dependences of the sensitivities of different environmental parameters on the specifications of the interferometer. A 30-mm-long fiber interferometer at a wavelength of 1593nm exhibits a temperature sensitivity of 0.103nm/°C, axial strain sensitivity of −1.35pm/μe, and refractive index sensitivity of −15.294nm/RIU, respectively. In addition to dependence on interferometer length, the sensitivities are also strongly dependent on the operation wavelength of the selected interference order. When the operation wavelength is selected at 1525nm, the sensitivities are 0.085nm/°C, −0.09pm/μe, and −13.824nm/RIU, respectively.
TL;DR: In this paper, a polarization beam splitter based on a self-collimation Mach-Zehnder interferometer (SMZI) in a hole-type silicon photonic crystal was proposed and numerically demonstrated.
TL;DR: In this paper, a novel filterless optical millimeter-wave generation scheme via two parallel dual-parallel Mach-Zehnder modulators (MZMs) is proposed.
Abstract: A novel filterless optical millimeter-wave generation scheme via two parallel dual-parallel Mach–Zehnder modulators (MZMs) is proposed. Theoretical analysis suggests that it can be used for the generation of millimeter-wave signal with octupling or 16-tupling of the local oscillator. An 80 GHz millimeter-wave is generated by octupling of a 10 GHz RF oscillator, or 16-tupling of a 5 GHz RF oscillator. Several influence factors on the performance of the optical sideband suppression ratio (OSSR) and the radio frequency spurious suppression ratio (RFSSR) are numerically studied. Simulation results show that the generated millimeter-wave can keep good performance, especially for octupling millimeter-wave generation; its performance is stable and insensitive to the extinction ratio of MZMs and the DC bias drift.