scholarly journals Spatiotemporal thermal analysis of taperedfibers in optical cavity sensing applications at633 nm and 1550 nm

OSA Continuum ◽  
2021 ◽  
Author(s):  
Ubaid Ullah ◽  
Imran Cheema
Keyword(s):  
Thermal Analysis ◽  
Optical Cavity ◽  
Sensing Applications

scholarly journals Bound in the continuum modes in indirectly-patterned hyperbolic media

2021 ◽  
Author(s):  
Frank Koppens ◽  
Hanan Herzig-Sheinfux ◽  
Lorenzo Orsini ◽  
Minwoo Jung ◽  
Iacopo Torre ◽  
...  
Keyword(s):  
Near Field ◽  
Optical Cavity ◽  
Bound State ◽  
Destructive Interference ◽  
Dramatic Improvement ◽  
Quality Factors ◽  
Strong Light ◽  
Sensing Applications ◽  
The Continuum ◽  
Nanoscale Level

Abstract A conventional optical cavity supports one or more modes, which are confined since they are unable to leak out of the cavity. Bound state in continuum (BIC) cavities are an unconventional alternative, based on confinement by destructive interference, even though optical leakage channels are available. BICs are a general wave phenomenon, of particular interest to optics, but BICs have never been demonstrated at the nanoscale level. Nanoscale BIC cavities are more challenging to realize, however, as they require destructive interference at the nanometer scale. Here, we demonstrate the first nanophotonic cavities based on BIC and find an unprecedented combination of quality factors and ultrasmall mode volume. In particular, we exploit hyperbolic media, HyM, as they can support large (in principle unlimited) momentum excitations, which propagate as ultra-confined rays, so that HyM cavities can in principle be extremely small. However, building a hyperbolic BIC (hBIC) cavity presents a fundamental challenge: an hBIC has an infinite number of modes, which would all need to interfere simultaneously. Here, we bring the BIC concept to the nanoscale by introducing and demonstrating a novel multimodal reflection mechanism of the ray-like optical excitations in hyperbolic materials. Using near-field microscopy, we demonstrate mid-IR confinement in BIC-based nanocavities with volumes down to 23x23x3〖nm〗^3 and quality factors above 100 – a dramatic improvement in several metrics of confinement. This alliance of HyM with BICs yields a radically novel way to confine light and is expected to have far reaching consequences wherever strong optical confinement is utilized, from ultra-strong light-matter interactions, to mid-IR nonlinear optics and a range of sensing applications.

scholarly journals Cooling of a levitated nanoparticle to the motional quantum ground state

Science ◽  
2020 ◽  
Vol 367 (6480) ◽  
pp. 892-895 ◽  
Author(s):  
Uroš Delić ◽  
Manuel Reisenbauer ◽  
Kahan Dare ◽  
David Grass ◽  
Vladan Vuletić ◽  
...  
Keyword(s):  
Ground State ◽  
Quantum Control ◽  
Optical Cavity ◽  
Optical Trap ◽  
Laser Cool ◽  
Complex Objects ◽  
Precise Control ◽  
Sensing Applications ◽  
Superposition States ◽  
Quantum Ground State

Quantum control of complex objects in the regime of large size and mass provides opportunities for sensing applications and tests of fundamental physics. The realization of such extreme quantum states of matter remains a major challenge. We demonstrate a quantum interface that combines optical trapping of solids with cavity-mediated light-matter interaction. Precise control over the frequency and position of the trap laser with respect to the optical cavity allowed us to laser-cool an optically trapped nanoparticle into its quantum ground state of motion from room temperature. The particle comprises 108 atoms, similar to current Bose-Einstein condensates, with the density of a solid object. Our cooling technique, in combination with optical trap manipulation, may enable otherwise unachievable superposition states involving large masses.

scholarly journals Probing gravity by holding atoms for 20 seconds

Science ◽  
2019 ◽  
Vol 366 (6466) ◽  
pp. 745-749 ◽  
Author(s):  
Victoria Xu ◽  
Matt Jaffe ◽  
Cristian D. Panda ◽  
Sofus L. Kristensen ◽  
Logan W. Clark ◽  
...  
Keyword(s):  
Noise Source ◽  
Optical Cavity ◽  
Hold Time ◽  
Gravitational Potential Energy ◽  
Vertical Separation ◽  
Fundamental Physics ◽  
Sensing Applications ◽  
Interferometer Phase ◽  
Phase Variance ◽  
Atom Interferometers

Atom interferometers are powerful tools for both measurements in fundamental physics and inertial sensing applications. Their performance, however, has been limited by the available interrogation time of freely falling atoms in a gravitational field. By suspending the spatially separated atomic wave packets in a lattice formed by the mode of an optical cavity, we realize an interrogation time of 20 seconds. Our approach allows gravitational potentials to be measured by holding, rather than dropping, atoms. After seconds of hold time, gravitational potential energy differences from as little as micrometers of vertical separation generate megaradians of interferometer phase. This trapped geometry suppresses the phase variance due to vibrations by three to four orders of magnitude, overcoming the dominant noise source in atom-interferometric gravimeters.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

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