Tanmoy Datta
@vmharipal.ac.in
Assistant Professor
Vivekananda Mahavidyalaya, Haripal
RESEARCH, TEACHING, or OTHER INTERESTS
Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Akash Kumar Pradhan, Chandra Prakash, Tanmoy Datta, Mrinal Sen, and Haraprasad Mondal
Springer Science and Business Media LLC
Haraprasad Mondal, Kamanashis Goswami, Tanmoy Datta, Rajesh Bose, Sandip Roy, and Anup Sharma
Springer Science and Business Media LLC
Akash Kumar Pradhan, Mrinal Sen, and Tanmoy Datta
Optica Publishing Group
In this work, a model for an on-chip all-photonic analog to digital converter is proposed. Here, the underlying quantization technique is based on slicing the supercontinuum generated inside the highly nonlinear nanocrystal embedded slotted photonic crystal waveguide at specifically chosen wavelengths. It is shown that although both the broadening and splitting of the spectrum can be used for four level quantization, only broadening can be used for designing eight (or more) level quantization. The highly nonlinear device system makes the eight level quantization scheme incremental within a footprint of 50×20µm2, which can convert 0–11 mW analog optical power to respective quantization levels. Although both Kerr and stimulated Raman scattering (SRS) contribute to the generation of the supercontinuum, the giant SRS gain of the silicon nanocrystal essentially outweighs that of the Kerr, with, consequently, unprecedented miniaturization in both operating power and footprint.
Kaushik Shukla, Tanmoy Datta, and Mrinal Sen
AIP Publishing
The paper proposes a novel microcantilever based optical temperature sensor/calorimeter for use in applications requiring high-resolution measurements. The cantilever beam is made of bi-material that deflects in response to the change in temperature because of the difference that exists between the thermal expansion coefficients of the respective two materials. The deflection of the cantilever is then detected by an equivalent change in the optical intensity received by an optical setup. Analyses of the sensitivity have been carried out for different materials for the bimorph. The proposed sensor demonstrates a resolution of 110 nK as a temperature sensor and 0.5 pW as a calorimeter at 5% error for Al/SiO2 bimorph. Such a high sensitivity in the said context has never been reported earlier.
Akash Kumar Pradhan, Mrinal Sen, and Tanmoy Datta
Optica Publishing Group
A comprehensive analysis of Raman mediated solitonic compression of pulses inside a silicon nanocrystal embedded slotted photonic crystal waveguide (SPCW) is presented. The ultrahigh Raman gain coefficient of the silicon nanocrystal material, being fortified further by the intense optical confinement inside the SPCW, essentially outweighs the contribution of the Kerr in the self-phase modulation phenomenon that is responsible for the solitonic propagation of a pulse. This work particularly emphasizes the contribution of Raman nonlinearity in the soliton dynamics, which however has been neglected conventionally, leading to an unprecedented miniaturization in both the operating power and footprint. Spatiotemporal evolution of pulses inside the SPCW has been calculated using the nonlinear Schrödinger equation considering the slow-light regime. A compression factor as high as 44.3 is obtained using a 30 µm long SPCW with a peak input power of 8 mW at 1550 nm.
Akash Kumar Pradhan, Mrinal Sen, and Tanmoy Datta
Elsevier BV
Anup Sharma, Kamanashis Goswami, Haraprasad Mondal, Tanmoy Datta, and Mrinal Sen
Springer Science and Business Media LLC
Yash Raj, Kaushik Shukla, Tanmoy Datta, and Mrinal Sen
Institute of Electrical and Electronics Engineers (IEEE)
Geophysical phenomena like volcanic eruptions, tectonic plate movements, and earthquakes directly influence the gravitational pull in the region of occurrence. Measurement of anomalies in the gravitational pull has been a useful technique in analyzing such activities quantitatively. Gravitational variations also carry indications of the presence of the earth’s minerals and other such useful resources. In this paper, a novel on-chip micro-cantilever-based optical gravimeter has been proposed for the precise measurement of gravitational changes. Simulations comprising both three-dimensional full-vector finite element and finite difference time domain methods have been carried out for analyses, demonstrating an extensive reading range of 6000 mGal with a resolution of <inline-formula> <tex-math notation="LaTeX">$1.17~\\mu $ </tex-math></inline-formula>Gal and sensitivity of <inline-formula> <tex-math notation="LaTeX">$1~\\mu $ </tex-math></inline-formula>Gal/<inline-formula> <tex-math notation="LaTeX">$\\sqrt {Hz}$ </tex-math></inline-formula> at 1 Hz.
Tanmoy Datta and Mrinal Sen
Institution of Engineering and Technology (IET)
A new device architecture of an all-optical logic inverter (AOLI) has been proposed in this study. The AOLI functions based on stimulated Raman scattering (SRS) in silicon nanocrystal embedded slotted photonic crystal waveguide (SPCW). The operating power and footprint size of the proposed device have significantly been scaled down to ∼1.5 mW and
, respectively, by combining the benefits of giant SRS gain of silicon nanocrystal and ultra-high spatio-temporal confinement of the SPCW. Cascadability of the proposed AOLI has been investigated using the maximum product criterion of the noise margin. The successful operation of the AOLI has been demonstrated for the repetition rate of the pulses as high as 100 Gbps. Finally, tolerance of performance of the design under different types of fabrication imperfections has also been calculated to establish its sustainability in a practical scenario.
Tanmoy Datta and Mrinal Sen
Optica Publishing Group
A new device architecture has been proposed in this paper implementing the all-optical cascadable logic NOR functionality. The device functions based on stimulated Raman scattering (SRS) in silicon nanocrystal embedded slotted photonic crystal waveguide (SPCW). Substantial miniaturizations both in operating power and overall footprint of the device have been achieved owing to the ultrahigh SRS gain of silicon nanocrystal and strong spatio-temporal confinement of the SPCW. Successful operation of the device has been demonstrated at a pulse rate that is as high as 125 Gbps.
T. Datta and M. Sen
Institution of Engineering and Technology (IET)
A completely new design for an all-silicon all-optical pass switch has been proposed based on the stimulated Raman scattering (SRS) in silicon nanocrystal embedded slotted photonic crystal waveguide (SPCW). Substantial miniaturisation in the device footprint and operating power has been attained by merging the benefits of the giant SRS gain and the ultra-high optical confinement of the SPCW. The proposed switch offers a tremendously high contrast ratio of ∼ 27 dB between the logic levels and an extraordinary bit rate of 125 Gbps.
Tanmoy Datta, Mrinal Sen, Shatrughna Kumar, and Akash Kumar Pradhan
SPIE-Intl Soc Optical Eng
Abstract. A silicon photonic crystal (PhC)-based structure is proposed to efficiently couple power from two different wavelengths, targeted to the application of an integrable Raman amplifier. The coupler uses two asymmetrical PhC waveguides as input ports which are joined together and the coupled power is directed to a slotted photonic crystal waveguide-based output port. Coupling efficiency and the other performance metrics are evaluated using a three-dimensional full-vector finite-difference time domain simulation method, which is tested for accuracy using some existing experimental structures and corresponding results. The heuristic approach has been adopted to optimize the design for maximizing the coupling efficiency. Dependence of the coupling performance on different design parameters has also been investigated. Simulations exhibit ∼3-dB coupling losses for both arms in a small footprint as small as ∼54 μm2.
Tanmoy Datta, Akash Kumar Pradhan, Shatrughna Kumar, and Mrinal Sen
IEEE
A unified mathematical framework has been presented in this paper to describe various manifestations of stimulated Raman scattering (SRS) in the slow-light regime, in presence of multiple pumps while simultaneously considering higher order Stokes. The presented framework also deals with other related optical nonlinearities, and remains valid in the sub-picosecond pulse-width regime.
Akash Kumar Pradhan, Tanmoy Datta, Partha Saha, and Mrinal Sen
IEEE
A width-modulated air-slot photonic crystal (PhC) nanocavity is designed and analyzed. A tapered air-slot, instead of a regularly arranged rectangular slot, is used at the center of a W1 PhC waveguide. This is to reduce the vertical radiation loss which occurs at the abrupt termination of a rectangular slot, and also to increase the inline coupling from a waveguide to the cavity. A three dimensional finite difference time domain method is used to calculate the resonant wavelength, quality factor and modal volume of the cavity which are found as 1.559 μm, 3.4×106 and 0.154 μm3 respectively.
Shatrughna Kumar, Tanmoy Datta, Akash Kumar Pradhan, and Mrinal Sen
IEEE
A silicon nanocrystal embedded Nonlinear Slotted Photonic Crystal Waveguide (NSPhCW) is proposed to reduce the length of the nonlinear section required in a typical all-optical switching device. Phase-variation of a pulse due to the effect of self-phase modulation and cross-phase modulation has been calculated and analysed under slow-light regime using a modified Nonlinear Schrodinger Equation (NSEs). A 180-degree phase shift is observed in a sub-hundred micrometer length of the NSPhCW even without the effect of XPM. Also, the addition of a control signal increases the change in phase shift more drastically and a same phase shift is attained in a smaller length.
Tanmoy Datta and Mrinal Sen
Elsevier BV
Tanmoy Datta and Mrinal Sen
Elsevier BV
Haraprasad Mondal, Saurav Chanda, Mrinal Sen, and Tanmoy Datta
IEEE
All-optical logic AND gate is realized by incorporating an elliptical structure at the Y-junction of two-dimensional photonic crystal waveguides. Principle of operation of the device is based on linear optics and, hence, the device consumes very low power while having very fast response time. The proposed device works in the 1550 nm wavelength band. Additionally, the simplicity of the device structure and also the integrable size makes the device very efficacious for the realization of all-optical logic gate.
Somenath Dutta, Tanmoy Datta, Mrinal Sen, and Arpan Deyasi
IEEE
New design for silicon based integrable coupler/pump-combiner is presented in the paper. The pump-combiner is designed with the view of efficient stimulated Raman scattering/Raman amplification in silicon waveguides. Performances of some couplers with well-known structure are also analyzed in this work. Analysis of the new coupler shows significant improvement in the transmittance performance compared with the well-known structures, discussed in the work.
Mrinal Sen, Tanmoy Datta, and Mukul K. Das
IEEE
The dependency of effective free carrier lifetime on the lateral dimensions of the Silicon on Insulator (SOI) p-i-n optical rib waveguide has been demonstrated. Effect of reverse bias on the same is also studied. Since carrier generation through two photon absorption is omnipresent in Si, the lifetime of the free carriers plays an important role in determining the net achievable Raman gain in SOI waveguides as it affects nonlinear absorption loss due to free carriers. A detailed analytical model has been derived for the assessment of effective lifetime of free carriers in reverse bias condition in various geometrical features of the waveguide.