High-speed optical communication networks with ter- abit transmission capabilities attract much attention, in terms of high capability and exibility in optical signal processing. Such ultrafast optical signal process- ing can be achieved using a SymmetricMachZehnder (SMZ) all opticalswitch family, including an origi- nal SMZ switch [1,2], a Delayed Interference Signal- wavelength Converter (DISC) , and a Polarization Discrimination SMZ (PD-SMZ) . The Semiconduc- tor Optical Amplier (SOA) is a key element in many ultrafast switching schemes. The speed of switches based on SOA is limited, especially because of SOA carrier dynamics. To overcome this limitation, dierent approaches have been used. Wang et al. proposed and experimentally demonstrated a SOA based dierential
waveguide. W 3 is the width of the second segment (homogenous Kerr medium) and W 4 the width of each channel of the output segment. In the first simulation related to structure shown in Figure 1(a), the peak power of the input pulse was kept as a constant value of 18 W, and only its wavelength is changed from 1.5 µm to 2.05 µm. Here the proposed switches rely on the wavelength variations, which causes phases difference in the first output segment of the switches and the signal to appear in different spatial locations of Mach-Zehnder output. This difference along with second segment swing properties causes the signal to extract in different channels due to input power and wavelength. The evolutions of such a input pulse with constant power propagating along 1 × 5 all-opticalswitch are demonstrated in Figure 2. Figure 2 and Table 2 reveal that when input signal wavelength is between 1.5 µm to 1.645 µm, the coupled signal passes from channel #1. For another case with wavelength between 1.645 µm to 1.73 µm, it passes from channel #2. The other results of the switch function related to wavelength ranges according to Table 2 present in Figures 2(c), 2(d), and 2(e). One of the most important characteristic of the designed switch is that by increasing the wavelength of the input signal, it sequentially switches to the output channel as desired which is demonstrated in Figure 2 and Table 2. Moreover, the simulations were repeated for the second structure shown in Figure 1(b) with the same peak power as mentioned above, and the results are given in Table 2 in which they also confirm that increasing the input signal wavelength shifts it toward the output channel sequentially, which means that by using symmetricMach-Zhender, beside easier and cheaper fabrication process, similar results to the asymmetric one are obtained.
A Mach-Zehnder interferometer (MZI) switch is a very powerful technique to realize ultrafast switching. The block diagram of a Symmetric SOA-assisted MZI switch is shown in Fig. 1. In this switch two SOAs (SOA-1 and SOA-2) are inserted in each arm of a MZI [7-14]. It has two input ports (port-1 and port-2) and two output ports (port-3 and port-4). The incoming signal pulse at the wavelength λ 2 enters port-1, is split equally by coupler C1 (50:50) and propagates simultaneously in the two arms of the
 G. Gumbs et al., “Plasmon excitations of multilayer graphene on a conducting substrate”, Sci. Rep, vol. 6, Article number 21063, 2016.  P.A. Thomas et al., “Strong coupling of diffraction coupled plasmons and optical waveguide modes in gold stripe dielectric Nano- structures at telecom wavelengths”, Sci. Rep., vol. 7, article number 45196, 2017.
The novelty of the proposed scheme is that the frequency of the generated mm wave signal is 30 times the frequency of applied microwave drive. Here, an overdriven Mach-Zehnder light intensity modulator is used to produce higher harmonics intensity modulation. The modulator is said to be over driven when the microwave signal voltage, V m applied to the modulator is greater than the half wave voltage of the modulator, V π . By
are useful for the resonator ring and Mach-Zehnder inter- ferometer applications at 138 GHz only. Since the reﬂec- tivity R is close to zero at 110 GHz, the power of 110 GHz can be transmitted without change by the diplexer. It is one choice of operating scenarios in the 2- f transmission. Fine tuning of the waveguide length for the operating frequency is required in the diplexer circuit, but it will be sometimes diﬃcult for the 2- f application in the rigid waveguide line. The diplexer works for only one frequency with the ﬁne tuning, and the other frequency power could be transmit- ted with no modiﬁcation of the transmission line. Points C and E are proposed for the diplexer application only at 110 GHz. Although the CW window has been well developed with the CVD-diamond plate, the CVD-diamond splitter still bears the risk of damage. The operating polarization is limited to s-polarization. The diplexer in circular cor- rugated waveguides is one of the attractive candidates, but some critical aspects are to be considered.
In the first instance the analyte refractive index range of interest is from 1.32 to 1.41, although future work exploiting these sensors may explore analytes having indices as high as 1.6, requiring the use of a substrate glass of commensurately high index. The Mach-Zehnder interferometer has been chosen for this instrument, as it shows high-sensitivity, is straightforward to design and fabricate, and is tolerant of manufacturing error. The interferometer responds to changes in the refractive index of analyte in the waveguide evanescent field in a region of one branch defined by a window in an isolation layer otherwise covering the device. However, sensitive transducer response to small changes in index requires that the device operates in a sensitive region of the response curve; this cannot be satisfied over the complete range of indices for a single-output MZI, which shows maxima and minima in the interference function. The use of a three-waveguide output coupler at the output of the MZI results in three outputs with interference functions which are shifted by nominally 120 with respect to each other. In this way at least one output yields a o sensitive response to small analyte index changes notwithstanding the starting value. While this tightens the constraints on manufacture somewhat, it also allows referencing the individual signals to the sum of the signals emerging from the three outputs, removing the effects of source intensity fluctuations. Alternatively, in conjunction with an independent reference output, it potentially allows measurement of the optical absorption of the analyte as well as its refractive index. In this paper we present measurements on multiple-output integrated optical sensor devices using fibre input coupling and a cheap, readily available, 1D CCD array detector to simultaneously address all outputs. This approach leads to a low-cost reconfigurable approach to the simultaneous acquisition of multiple outputs. A lens is used to focus the waveguide outputs onto the array, resulting in a compact unit that can be housed in a standard instrument package. A further advantage of this arrangement is that other optical elements such as filters and polarisers can readily be inserted into the beam path. Work is presently in progress to precisely stabilise the temperature of the sensor surface through feedback control and to explore the use of selective polymers in sensor arrays for quantification of chemical species of interest in beverage analysis. 2. TRANSDUCER DESIGN
between the normalized output power and the protein concentration According to Eq. (8), the sensor dynamic range expressed in terms of protein concentration is equal to ∆c = 0.37 g/ml as given by the range of variability of the biolayer refractive index. The sensitivity and the protein concentration dynamic range depend only on the performance of the sensor itself, irrespective of the overall measurement setup, whereas the measurement setup influences the resolution achievable. As an example, considering an output optical power dynamic range equal to 100 mW the non-normalized sensitivity is equal to 160 mW/(g/ml). Considering an optical power meter, having resolution equal to 1 nW, the minimum measurable value of the protein concentration c in aqueous phase is about 6 ng/ml (i.e., the ratio between the power meter resolution and the non-normalized sensitivity).
Reversible logic is becoming a popular emerging paradigm because of its applications in various emerging technologies like quantum computing, DNA computing, optical computing,etc. It is also considered as an alternate low-power design methodology. A reversible circuit consists of a cascade of reversible gates without any fanout or feedback connections, and the number of inputs and outputs must be equal. There exists various ways by which reversible circuits can be implemented like NMR technology, optical technology, etc.In the optical domain, a photon can store information in a signal having zero rest mass and provide very high speed. These properties of photon have motivated researchers to study and implement reversible circuits in optical domain. Theoretically from the decade old principles of Landauer and Bennett , reversible logic is considered as a potential of reversible gates can be one possible alternative to
are used to design the sequential circuits. Our primary objective in this work isto achieve the reversible implementation of counters with minimum number of ancilla lines and MZI switches. All optical implementation of MZI-based asynchronous and synchronous counter is presented. Mathematical model to simulate the proposed architecture has also been presented.Finally, design complexities of all the counters are analyzed.
O ne of the most vital objectives of optical digital computation techniques is to develop the performances of basic and complex digital devices. Optical logic device is a better alternative to process the information with high speed as it can realize a number of operations such as multiplexing, switching, addressing, coding/decoding and complex digital computations. Hence, it is a timely interest of many researchers to realize various logic gates optically, and XOR and XNOR in particular. Because, these two optical logic devices provide way for realization of number of other functions such as equality detectors, parity generators and code converters also. The ultrafast all-optical XOR gate using two types of semiconductor optical amplifier based SOA-MZI was analyzed and key parameters were optimized through mathematical simulations by Zhang et al.. The electro-optic effect based optical switching phenomena in MZI was efficiently considered and it was broadly investigated to implement the optical full adder and full subtractor by Ajay Kumar et al.. In digital communication, parity generator and checker had been used to retrieve the lost information. But, realizing them optically was not possible for
Abstract---- Use of optical fiber communication is widely use due to its better bit rate and bandwidth and high carrier frequency with low power consumption. So, in this paper, we have analyzed non linear modulation techniques that are self phase modulation (SPM) and cross phase modulation (CPM) in an optical fiber system and discussed how these cause dispersion in input signal. These effects are simulated using OPTISYSTEM tool at a bit rate of 10Gbps and analyzed by eye pattern method with respect to bit error rate and Q factor. Simulation results of self phase modulation and cross phase modulation obtained in OPTISYSTEM tool which is made by OPTIWAVE INC. are compared with each other. Formula for bit error rate (BER) is implemented in MATLAB and its value is obtained by taking the value of Q factor from the design implemented in OPTISYSTEM and further variations in the value of BER are studied for both types of non linear effects and see that which type of modulation is better for long transmission in single mode optical fiber.
This paper reports on a simple approach of determining the ability of a transparent material, such as cellophane to rotate the direction of polarization of a light beam. In order to determine the birefringence of such a material, a Mach-Zehnder interferometer is used to generate interference patterns when the cellophane sheet is mounted on one arm such as to intercept a portion of the laser beam. The recorded interferograms show a phase shift which is calculated to be 0.98π radians. By rotating the cellophane sheet on the object beam, the fringe separation is measured for different angles and the values used to calculate the ordinary and extraordinary refractive indices as 1.4721 ± 0.0002 and 1.4680 ± 0.0002 respectively at 632.8 nm wavelength. A surface error of approximately λ/16 (peak to valley) is measured from the re- corded interferograms. Because of its sufficient birefringence and small thickness of 24 µm, cellophane can be used to fabricate special polarization pupil masks by cutting and aligning different cellophane structures appropriately.
The concepts and applications of nonclassical states like squeezing and entangled states have been considered by many authors [1–4]. Recently, squeezing and entangled states have found many applications in diﬀerent ﬁelds [5–8], and many experimental setups have been presented to check the properties and applications of quantum entangled states [9–11]. Measurement and manipulation of quantum states, especially in quantum cavities, are a milestone for the development and improvement of atom-photon interaction methods [12–14], quantum teleportation , quantum cryptography , measuring the Wigner function of cavity ﬁeld [17, 18], detecting photons in a cavity by non-demolition method [4, 19], quantum information and invention of quantum computers [20, 21], etc. A winner of the Nobel Prize, Serge Haroche, has presented an interesting non-demolition method for measuring Wigner function in a quantum cavity . On the other hand, the Mach-Zehnder interferometry is applied to Bell’s inequality [22, 23], electronic Mach-Zehnder interferometer (MZI) , single and two photon interferometry [25, 26], production and observation of Greenberger-Horne-Zeilinger entanglement , and optical ampliﬁcation [28, 29].
Nonlinear optical phenomena occur when we apply an optical field and the response of the material would be nonlinear such as frequency doubling ”Second-Harmonic Genera- tion (SHG)”. This is a nonlinear optical process that occurs when photons with the same frequency interact with a nonlinear material and generate new photons with twice the fre- quency, so that the atomic response that balances quadratically at frequency 2ω with the
ABSTRACT: At the high power level the impairment of the signal transmission leads to the nonlinear effects.Here Concentrate On the Self Phase Modulation that induces the degradation of system performance.For this reason, SPM is reduced with the help of the MachZehnder Modulator for Error Free transmission of signal.This technique is suitable for 50Km, above this distance SPM is reduced but Eye Height is narrow compared with 50Km.Because Narrow Eye Height justifies more Crosstalk and vice versa.Eye Height decreases with increase in input power.SPM is reduced after that with the help of MZM, Optimum value of input power and varyfiber length such as 50km, 60km, 70km, 80km that produces the different values of BER, Q-factor, Eye Height.These are compared and fixed anyone distance which one is provide better performance than others.This analysis is done with the help of Optisystem12.0 Software.
We simulate many signals to verify that the effectiveness of extracting the character of various vibration signals by power spectrum estimation combined autocorrelation. Fundamental frequency is the main frequency components of free vibration of optical fiber and may also contain other harmonic frequencies. Otherwise, the signals of forced vibration depend on external force, so demodulation signals do not have obvious fundamental frequency component as inherence frequency for features. The simulation of non-intrusion and intrusion signals are compounded by sine wave, based on the theory of system. As the frequency-energy distribution of operating environment is unkown, here the simulation experiment which only extracts fundamental frequency from signals has been carried to verify the effectiveness of autocorrelation, then according to the calculated fundamental frequency, we can distinguish the type of vibration which can be used to discriminate intrusion. Fig. 9 shows the autocorrelation of free vibration and forced vibration.
Abstract—A procedure using stimulated annealing algorithm to design the reference function is proposed. First we encode color pattern into a single channel and use the minimum average correlation energy to obtain an initial feasible solution and the state. Then we substitute the solution into stimulated annealing algorithm to obtain the optimizing reference function, and utilize the multilevel quantitative analysis of the reference function. Finally we utilize Mach-Zehnder joint transform correlator with simulated annealing to obtain the optimization of the reference function for recognition of color targets. From numerical results, the performance is accepted.
measurement the proper beam expander is inevitable in the setup with double path. Double paths setup brings the benefit of double sensitivity but on the other hand any wavefront distortions caused by imperfections in the optical system of expander are boubled as well. The expander imperfections could origin either from improper assembly of expander or more frequently from non optimized design. The working principle is shown in Fig. 10.