A5019628231- Photonic and Optical Devices
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Advanced Fiber Laser Technologies
- Advanced Fiber Optic Sensors
- Neural Networks and Reservoir Computing
- Analytical Chemistry and Sensors
- Semiconductor Lasers and Optical Devices
- Acoustic Wave Resonator Technologies
- Nonlinear Photonic Systems
- Advanced MEMS and NEMS Technologies
- Liquid Crystal Research Advancements
Boston University
2021-2024
Banaras Hindu University
2016
A spiral shaped plastic optical fiber (POF) has been constructed and applied for sensing of the refractive index a sucrose solution. The mechanism is based on evanescent wave interaction between light travelling within medium surrounding it. Difference in output voltage observed as concentration solution varied from 10% to 50%, demonstrating uniform relation among them. By varying pitch shape applying strain same, sensitivity POF refined. This spiral-shaped sensor comparatively easy...
Emerging applications of photonic integrated circuits are calling for extremely narrowband and/or low-insertion-loss bandpass filters. Both properties limited by cavity losses or intrinsic quality factors. However, the choice inter-cavity and bus couplings establishes trade-offs between these two passband shape, which have been little explored. Using widely used second-order resonant system as an example, we present new, to best our knowledge, classes filter shapes that provide lowest...
Electro-optic (EO) transduction of weak radio frequency (RF) and millimeter-wave signals, such as those received by an antenna, onto laser sidebands for processing in the optical domain requires efficient EO modulators. Microrings offer spatial density efficiency advantages over Mach–Zehnder modulators (MZMs), but conventional single-ring suffer a fundamental trade-off between resonantly enhanced conversion RF carrier that it can accommodate. Dual-cavity “photonic molecule” resolve this...
This work presents a fully-integrated electronic-photonic mm-wave sensing element, fabricated in commercial 45 nm SOI process. The element features low-noise amplffier (LNA) tuned to drive an integrated electro-optical microring modulator (MRM) instead of conventional Mach-Zehnder (MZM) with large footprint. With power only 30mW and area 0.6m$\mathrm{m}^{2}$, the design enables compact, low-power sensor arrays thousands elements, paving way new distributed cellfree radio architectures....
Electro-optic (EO) transduction of weak radio-frequency (RF) and millimeter-wave signals, such as those received by an antenna, onto laser sidebands for processing in the optical domain requires efficient EO modulators. Microrings offer spatial density efficiency advantages over Mach-Zehnder modulators, but conventional single-ring modulators suffer a fundamental trade-off between resonantly-enhanced conversion RF carrier frequency that it can accommodate. Dual-cavity ``photonic molecule''...
Electro-optic (EO) transduction of weak radio-frequency (RF) and millimeter-wave signals, such as those received by an antenna, onto laser sidebands for processing in the optical domain requires efficient EO modulators. Microrings offer spatial density efficiency advantages over Mach-Zehnder modulators, but conventional single-ring modulators suffer a fundamental trade-off between resonantly-enhanced conversion RF carrier frequency that it can accommodate. Dual-cavity ``photonic molecule''...
Recently discovered ferroelectric nematic liquid crystal promises to enable both strong phase shifters and fast Pockels’ effect modulation without poling. We demonstrate the first silicon slot-waveguide hybrid integration up 35 GHz.
We present a compact optical switch with rapid adiabatic coupling, achieving high extinction ratios over 75 nm wavelength in 1-by-2 unit. A 1-by-8 tree driven by three inputs is also demonstrated.
We demonstrate a Dual Active-Cavity RF modulator combining T-shaped spoked junction with novel “half-rib” waveguide in monolithic electronic-photonic platform. measure sideband efficiency of -52 dB at 66 GHz carrier frequency.
We demonstrate a novel compact, ultra-broadband polarization splitter-rotator (PSR) based on photonic magic-T and rapid adiabatic mode splitter (RAMS). Polarization cross-talk is < -14dB over 70 nm around 1550 nm, with IL -0.3dB > 5 × length reduction conventional PSR.
We propose photonic molecule electro-optic modulators with tunable supermode splitting for efficient widely RF sideband generation. Using an auxiliary off-resonant cavity as a variable coupler maintains high Q/V.
Numerous emerging applications of photonic integrated circuits are calling for extremely narrowband and/or low-insertion-loss bandpass filters. Both properties fundamentally limited by resonator losses, i.e. the intrinsic quality factor constituent resonant cavities. However, choice inter-cavity and bus couplings establishes tradeoffs between these two passband shape, which have been little explored. Using widely-used second-order system as example, we show that new classes filter shapes...
Numerous emerging applications of photonic integrated circuits are calling for extremely narrowband and/or low-insertion-loss bandpass filters. Both properties fundamentally limited by resonator losses, i.e. the intrinsic quality factor constituent resonant cavities. However, choice inter-cavity and bus couplings establishes tradeoffs between these two passband shape, which have been little explored. Using widely-used second-order system as example, we show that new classes filter shapes...
We demonstrate CMOS-integrated mm-wave-to-optical sensing elements comprising LNAs and triple-ring modulators that break the conversion-bandwidth tradeoff, showing a projected noise figure of 24 dB at 57 GHz (30 mW/element, -45dBm RF-input, 6dBm laser LO). The are tileable small pitches, enabling photonic disaggregation large-scale phased arrays.
We extend our proposal of efficient passive “noise eaters” based on Q-engineered Kerr OPOs to χ ( 2 ) systems, which could approach 100% conversion efficiency. show that existing state-of-the-art integrated devices can implement significant signal linewidth narrowing using this concept.
We demonstrate an adiabatic magic T in a 45 nm CMOS photonics foundry platform, with 3 ± 0.25 dB power splitting and < 1.2 loss over 1530-1600 nm, 60 µm-long device. It functions as 2 × beam splitter ratio from both input ports fundamentally robust by symmetry, supports novel polarization diversity modulator designs.
We investigate a linear configuration of coupled cavity resonators based on tri-diagonal Kac matrix which enables such cavities to support finite equi-spaced comb resonances. Such resonator may allow designing decouple size from spacings.
A finite-equispaced-comb resonator based on N “Kac-matrix” coupled cavities could be an important photonic building block. To maximally excite all comblines: there’s a best cavity to couple the bus waveguide; and, we “critically couple” geometric mean of supermode escape rates.