scholarly journals Breaking the diffraction limit in absorption spectroscopy using upconverting nanoparticles

Nanoscale ◽  
2021 ◽  
Author(s):  
Sumeet Kumar ◽  
Rahul Vaippully ◽  
Gunaseelan Murugan ◽  
Ayan Banerjee ◽  
Basudev Roy
Keyword(s):  
Absorption Spectroscopy ◽  
Diffraction Limit ◽  
Optically Trapped ◽  
Mode Volume

We employ a single optically trapped upconverting nanoparticle (UCNP) of NaYF$_4$:Yb,Er of diameter about 100 nm as a subdiffractive source to perform absorption spectroscopy. The experimentally expected mode volume of...

Surface imaging beyond the diffraction limit with optically trapped spheres

2015 ◽  
Vol 10 (12) ◽  
pp. 1064-1069 ◽  
Author(s):  
Lars Friedrich ◽  
Alexander Rohrbach
Keyword(s):  
Diffraction Limit ◽  
Surface Imaging ◽  
Optically Trapped

Absorption Spectroscopy of Single Optically Trapped Gold Nanorods

Nano Letters ◽  
2015 ◽  
Vol 15 (11) ◽  
pp. 7731-7735 ◽  
Author(s):  
Zhongming Li ◽  
Weizhi Mao ◽  
Mary Sajini Devadas ◽  
Gregory V. Hartland
Keyword(s):  
Absorption Spectroscopy ◽  
Gold Nanorods ◽  
Optically Trapped

scholarly journals Plasmonic nanolasers: fundamental properties and applications

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ren-Min Ma ◽  
Si-Yi Wang
Keyword(s):  
Scaling Laws ◽  
Diffraction Limit ◽  
Stimulated Emission ◽  
Optical Diffraction ◽  
Low Loss ◽  
Physical Size ◽  
New Class ◽  
Fundamental Properties ◽  
Threshold Gain ◽  
Mode Volume

Abstract Plasmonic nanolasers are a new class of coherent emitters where surface plasmons are amplified by stimulated emission in a plasmonic nanocavity. In contrast to lasers, the physical size and mode volume of plasmonic nanolasers can shrink beyond the optical diffraction limit, and can be operated with faster speed and lower power consumption. It was initially proposed by Bergman and Stockman in 2003, and first experimentally demonstrated in 2009. Here we summarize our studies on the fundamental properties and applications of plasmonic nanolasers in recent years, including dark emission characterization, scaling laws, quantum efficiency, quantum threshold, gain and loss optimization, low loss plasmonic materials, sensing, and eigenmode engineering.

Ultrasensitive Absorption Spectroscopy of Optically-Trapped Aerosol Droplets

2008 ◽  
Vol 112 (42) ◽  
pp. 10439-10441 ◽  
Author(s):  
Kerry J. Knox ◽  
Jonathan P. Reid
Keyword(s):  
Absorption Spectroscopy ◽  
Optically Trapped

scholarly journals Nanometer-scale photon confinement inside dielectrics

2021 ◽  
Author(s):  
Marcus Albrechtsen ◽  
Babak Vosoughi Lahijani ◽  
Rasmus Christiansen ◽  
Vy Nguyen ◽  
Laura Casses ◽  
...  
Keyword(s):  
Single Photon ◽  
Near Field ◽  
Critical Role ◽  
Diffraction Limit ◽  
Optical Measurements ◽  
Nanometer Scale ◽  
Common Definition ◽  
Photon Confinement ◽  
Definition Of ◽  
Mode Volume

Abstract Optical nanocavities confine and store light, which is essential to increase the interaction between photons and electrons in semiconductor devices, enabling, e.g., lasers and emerging quantum technologies. While temporal confinement has improved by orders of magnitude over the past decades, spatial confinement inside dielectrics was until recently believed to be bounded at the diffraction limit. The conception of dielectric bowtie cavities (DBCs) shows a path to photon confinement inside semiconductors with mode volumes bound only by the constraints of materials and nanofabrication, but theory was so far misguided by inconsistent definitions of the mode volume and experimental progress has been impeded by steep nanofabrication requirements. Here we demonstrate nanometer-scale photon confinement inside 8 nm silicon DBCs with an aspect ratio of 30, inversely designed by fabrication-constrained topology optimization. Our cavities are defined within a compact device footprint of 4 lambda^2 and exhibit mode volumes down to V = 3E-4 lambda^3 with wavelengths in the lambda = 1550 nm telecom band. This corresponds to field localization deep below the diffraction limit in a single hotspot inside the dielectric. A crucial insight underpinning our work is the identification of the critical role of lightning-rod effects at the surface. They invalidate the common definition of the mode volume, which is prone to gauge meretricious surface effects or numerical artefacts rather than robust confinement inside the dielectric. We use near-field optical measurements to corroborate the photon confinement to a single nanometer-scale hotspot. Our work enables new CMOS-compatible device concepts ranging from few- and single-photon nonlinearities over electronics-photonics integration to biosensing.

Confocal Raman mapping

1992 ◽  
Vol 50 (2) ◽  
pp. 1514-1515
Author(s):  
J. Barbillat ◽  
M. Delhaye ◽  
P. Dhamelincourt
Keyword(s):  
Chemical Species ◽  
Diffraction Limit ◽  
Microscopic Level ◽  
Raman Mapping ◽  
Complete Spectrum ◽  
Laser Illumination ◽  
Ccd Detector ◽  
Raman Microprobe ◽  
Photodiode Array ◽  
Raman Image

Raman mapping, with a spatial resolution close to the diffraction limit, can help to reveal the distribution of chemical species at the surface of an heterogeneous sample.As early as 1975,three methods of sample laser illumination and detector configuration have been proposed to perform Raman mapping at the microscopic level (Fig. 1),:- Point illumination:The basic design of the instrument is a classical Raman microprobe equipped with a PM tube or either a linear photodiode array or a two-dimensional CCD detector. A laser beam is focused on a very small area ,close to the diffraction limit.In order to explore the whole surface of the sample,the specimen is moved sequentially beneath the microscope by means of a motorized XY stage. For each point analyzed, a complete spectrum is obtained from which spectral information of interest is extracted for Raman image reconstruction.- Line illuminationA narrow laser line is focused onto the sample either by a cylindrical lens or by a scanning device and is optically conjugated with the entrance slit of the stigmatic spectrograph.

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