We report ultra-compact surface-normal high-Q optical filters based on single- and double-layer stacked Fano resonance photonic crystal slabs on both Si and quartz substrates. A single layer photonic crystal filter was designed and a Q factor of 1,737 was obtained with 23 dB extinction ratio. With stacked double-layer photonic crystal configuration, the optical filter Q can increase to over 10,...

X this pat)er we consider th effect ofthe damping or resistive mechanical loads on the characteristics of a piezoelectric crystal system vibrating in either a longitudinal or thickness mode. [n particular, the effect on the resonant and antiresonance frequencies is discussed. l.osses in the interior o[ the crystal are 'neglected. A quality [actor is defined [or damped crystal systems. The value...

Recently researchers have demonstrated ultra high quality factor (Q) resonances in one-dimensional (1D) dielectric gratings. Here we theoretically investigate a new class of subwavelength 1D gratings, namely "diatomic" gratings with two nonequivalent subcells in one period, and utilize their intrinsic dark modes to achieve robust ultra high Q resonances. Such "diatomic" gratings provide extra d...

Quantum vacuum forces dictate the interaction between individual atoms and dielectric surfaces at nanoscale distances. For example, their large strengths typically overwhelm externally applied forces, which makes it challenging to controllably interface cold atoms with nearby nanophotonic systems. Here we theoretically show that it is possible to tailor the vacuum forces themselves to provide s...

We derive an expression for the lower bound of the phase-space beam quality factor M(2) of an ultrashort pulse. We show that the condition M(2)>or=1 does not, in general, hold for such pulsed beams. Rather, the minimum value of M(2) depends on the pulse spectrum. We also show that M(2) attains minimum only for pulsed beams whose spot size varies with frequency as omega(-1/2), and that the radia...

We study synchronization and noise-induced resonance phenomena in systems of globally coupled oscillators, each possessing finite inertia. The behavior of the order parameter, which measures the collective synchronization of the system, is investigated as the noise level and the coupling strength are varied, and hysteretic behavior is manifested. The power spectrum of the phase velocity is also...

We study effective spatial and angular correlations in beams of any state of spatial coherence, and we introduce a phase-space product, Q , which takes these correlations into account. This phase-space product is shown to reduce to the conventional beam-quality factor M(2) when the beam is spatially fully coherent. We also determine the lower bound for the value of Q and demonstrate that it is ...

A new class of partially coherent beams with a separable phase, which carry optical vortices, is introduced. It is shown that any member of the class can be represented as an incoherent superposition of fully coherent Laguerre-Gauss modes of arbitrary order, with the same azimuthal mode index. The free-space propagation properties of such partially coherent beams are studied analytically, and t...