Magneto-optical resonance of the polarized fluorescence in a paraffin-coated87Rb vacuum cell

2015 ◽  
Author(s):  
E. T. Taskova ◽  
E. A. Alipieva ◽  
G. Tz. Todorov
1980 ◽  
Vol 41 (C9) ◽  
pp. C9-463-C9-469
Author(s):  
J. H.S. Wang ◽  
J. Finzi ◽  
P. K. Baily ◽  
K. K. Hui ◽  
G. W. Holleman

2007 ◽  
Vol 2 (2) ◽  
pp. 257-264
Author(s):  
Satoko Nishiyama ◽  
Masahiro Tajima ◽  
Yasuhiko Yoshida

Nanophotonics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 3535-3544 ◽  
Author(s):  
Laura Mercadé ◽  
Leopoldo L. Martín ◽  
Amadeu Griol ◽  
Daniel Navarro-Urrios ◽  
Alejandro Martínez

AbstractCavity optomechanics has recently emerged as a new paradigm enabling the manipulation of mechanical motion via optical fields tightly confined in deformable cavities. When driving an optomechanical (OM) crystal cavity with a laser blue-detuned with respect to the optical resonance, the mechanical motion is amplified, ultimately resulting in phonon lasing at MHz and even GHz frequencies. In this work, we show that a silicon OM crystal cavity performs as an OM microwave oscillator when pumped above the threshold for self-sustained OM oscillations. To this end, we use an OM cavity designed to have a breathing-like mechanical mode at 3.897 GHz in a full phononic bandgap. Our measurements show that the first harmonic of the detected signal displays a phase noise of ≈−100 dBc/Hz at 100 kHz. Stronger blue-detuned driving leads eventually to the formation of an OM frequency comb, whose lines are spaced by the mechanical frequency. We also measure the phase noise for higher-order harmonics and show that, unlike in Brillouin oscillators, the noise is increased as corresponding to classical harmonic mixing. Finally, we present real-time measurements of the comb waveform and show that it can be fitted to a theoretical model recently presented. Our results suggest that silicon OM cavities could be relevant processing elements in microwave photonics and optical RF processing, in particular in disciplines requiring low weight, compactness and fiber interconnection.


1991 ◽  
Author(s):  
B. George Barisas ◽  
N. A. Rahman ◽  
Thomas Londo ◽  
J. R. Herman ◽  
Deborah A. Roess

Author(s):  
Arpan Dutta ◽  
Tarmo Nuutinen ◽  
Khairul Alam ◽  
Antti Matikainen ◽  
Peng Li ◽  
...  

Abstract Plasmonic nanostructures are widely utilized in surface-enhanced Raman spectroscopy (SERS) from ultraviolet to near-infrared applications. Periodic nanoplasmonic systems such as plasmonic gratings are of great interest as SERS-active substrates due to their strong polarization dependence and ease of fabrication. In this work, we modelled a silver grating that manifests a subradiant plasmonic resonance as a dip in its reflectivity with significant near-field enhancement only for transverse-magnetic (TM) polarization of light. We investigated the role of its fill factor, commonly defined as a ratio between the width of the grating groove and the grating period, on the SERS enhancement. We designed multiple gratings having different fill factors using finite-difference time-domain (FDTD) simulations to incorporate different degrees of spectral detunings in their reflection dips from our Raman excitation (488 nm). Our numerical studies suggested that by tuning the spectral position of the optical resonance of the grating, via modifying their fill factor, we could optimize the achievable SERS enhancement. Moreover, by changing the polarization of the excitation light from transverse-magnetic to transverse-electric, we can disable the optical resonance of the gratings resulting in negligible SERS performance. To verify this, we fabricated and optically characterized the modelled gratings and ensured the presence of the desired detunings in their optical responses. Our Raman analysis on riboflavin confirmed that the higher overlap between the grating resonance and the intended Raman excitation yields stronger Raman enhancement only for TM polarized light. Our findings provide insight on the development of fabrication-friendly plasmonic gratings for optimal intensification of the Raman signal with an extra degree of control through the polarization of the excitation light. This feature enables studying Raman signal of exactly the same molecules with and without electromagnetic SERS enhancements, just by changing the polarization of the excitation, and thereby permits detailed studies on the selection rules and the chemical enhancements possibly involved in SERS.


2011 ◽  
Author(s):  
Manas Ranjan Gartia ◽  
Austin Hsiao ◽  
Mayandi Sivaguru ◽  
Yi Chen ◽  
G. Logan Liu

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