Sanjeev Kumar Raghuwanshi

Effect of Laser Modulation on Dispersion Induced Chirp Microwave Signal Generation by Using Temporal Pulse Shaping Technique

A photonic approach for generating an arbitrary chirp microwave waveform using optical coupler of different length is proposed and experimentally demonstrated. The chirp microwave waveform can be used in Radar system to improve its range Doppler resolution. The paper give the specific details about various performance parameters like input signal frequency and power, output signal parameters viz output frequency, chirp rate, chirp bandwidth and time bandwidth product etc. In this proposed approach two single mode optical fibers of different lengths are used to create the phase variation of the light coming from the continuous wave laser. The overall model and its performance parameters are computed on optiwave software and compared with experimental results carried out in lab which shows the validity of our experimental setup.

Modeling and analysis of overmodulation in erbium-doped fiber amplifiers including amplified spontaneous emission

Abstract. Line surveillance and management information in erbium-doped fiber amplifiers (EDFAs) can be broadcast by modulating the amplitude of the low-frequency lightwave information signal, the process termed as overmodulation in the literature. This paper presents systematic solutions for the overmodulated pump and information signal transfer functions for EDFA. It includes amplified spontaneous emission (ASE) that has an impact on outcomes in the high-gain system. To the extent of our belief, the methodical model simulated with the current approach leads to a distinct perspective of an outcome in the respective field. The test bed described here is realistic. It specifically represents the overmodulation behavior in an EDFA under the influence of ASE.

A novel approach to generate a chirp microwave waveform using temporal pulse shaping technique applicable in remote sensing application

ABSTRACT Microwave photonics is a prominent field in which photonic technologies are used to empower and extend the functionalities of microwave system which is a very tough exercise to fulfil directly in microwave domain. A photonic technique to generate a high chirp rate arbitrary microwave waveform using dual-drive LiNbO3 has been put forward and demonstrated experimentally in this paper. Nowadays in order to increase the Range-Doppler resolution of radar, the chirp microwave waveform is widely used. The Mach-Zehnder modulator (MZM) performs the intensity modulation techniques which can operate on the principle of electro-optic effect. In this paper, the authors used a very simple and straightforward method of producing chirped arbitrary millimetre waveform by change in phase at the two arms of dual-drive LiNbO3 MZM. The generated waveform has the 3 dB bandwidth of 12.6 GHz which exists in extremely high-frequency band applicable in high-frequency microwave radio relay, microwave remote sensing, radar range resolution and millimetre wave scanner. The proposed design is simpler, cost-effective and compact than the previously proposed model of chirped waveform generation using MZM and fibre Bragg grating.

Review on Liquid-level Measurement and Level Transmitter Using Conventional and Optical Techniques

ABSTRACT Liquid-level measurement in storage tank system play an important role in industrial application such as in food processing, pharmaceutical industry, chemical industry, water purification system, petroleum industry and many more. Corrosive environments and turbulence can cause accidents and overflowing, taking a few of the conditions into consideration a measurement device must endure if it is to fulfil its goal of accuracy, linearity and dependability. So there are many well-established techniques to measure the liquid levels for different heights. In this paper, we have thoroughly reviewed the conventional as well as optical techniques of the liquid-level measurement and transmitting techniques of the measured quantity. Section 2 covers the different sensor designs while Section 3 covers transmitting technologies followed by conclusion in Section 4.

High sensitive pressure sensor based on plasmonic Mach-Zehnder interferometer

In this paper we theoretically realize the all optical pressure sensor using the Mach-Zehnder interferometer (MZI). In this model, one arm of MZI is plated with silver and surrounded with specially design polymer filled metal cylinder with opening at one side where pressure applied. The MZI structure can be effectively used to sense surface plasmon resonance and used as an efficient pressure sensor. The paper includes the suitable expressions for the optimizing the power entering each branch of the Mach-Zehnder interferometer, the SPR phase and amplitude changes. The results are very effectively supported by the use of COMSOL and MATLAB.

Reliable before-fabrication forecasting of normal and touch mode MEMS capacitive pressure sensor: modeling and simulation

Abstract. An analytical model and numerical simulation for the performance of MEMS capacitive pressure sensors in both normal and touch modes is required for expected behavior of the sensor prior to their fabrication. Obtaining such information should be based on a complete analysis of performance parameters such as deflection of diaphragm, change of capacitance when the diaphragm deflects, and sensitivity of the sensor. In the literature, limited work has been carried out on the above-stated issue; moreover, due to approximation factors of polynomials, a tolerance error cannot be overseen. Reliable before-fabrication forecasting requires exact mathematical calculation of the parameters involved. A second-order polynomial equation is calculated mathematically for key performance parameters of both modes. This eliminates the approximation factor, and an exact result can be studied, maintaining high accuracy. The elimination of approximation factors and an approach of exact results are based on a new design parameter (δ) that we propose. The design parameter gives an initial hint to the designers on how the sensor will behave once it is fabricated. The complete work is aided by extensive mathematical detailing of all the parameters involved. Next, we verified our claims using MATLAB® simulation. Since MATLAB® effectively provides the simulation theory for the design approach, more complicated finite element method is not used.