This paper describes the design and implementation of a second-order switched-capacitor (SC) bandpass (BP) filter with very wide quality factor (Q) programmability range. The filter selectivity is digitally programmed by varying the effective sampling frequency of an SC branch, without modifying any capacitor value. The proposed approach allows a quasi-continuous Q-factor tunability avoiding, i...

Introduction: Guided mode resonance is generated by coupling wave diffractions with the waveguided mode. The guided resonances provide narrow-linewidth and intensity for high quality factor (Q-factor) optical resonators. Methods: we demonstrate high-Q propagating on a low-loss, terahertz guided-mode magnetic system, which are periodic square lattices of U-shaped split ring resonators (SRRs) qua...

We uncover how to achieve giant Q-factors in finite-length periodic arrays of subwavelength optical resonators. The underlying physics is based on interference between the band-edge mode and a standing array, it leads formation spatially localized states with dramatically suppressed radiative losses. demonstrate this concept for an array N dipoles simultaneous cancellation multipoles up N-th or...

A subjective test study was carried out in order to identify the perceptibility of changes in the Q-factor of room modes. The experimental technique concentrates on the identification of difference limen for three levels of Q-factor referring to modes in rooms used for critical listening. Trends show that changes in higher Q values are more perceptible than those for lower Q values. The results...

Ras guanine nucleotide exchange factor (GEF) Q, a nucleotide exchange factor from Dictyostelium discoideum, is a 143-kD protein containing RasGEF domains and a DEP domain. We show that RasGEF Q can bind to F-actin, has the potential to form complexes with myosin heavy chain kinase (MHCK) A that contain active RasB, and is the predominant exchange factor for RasB. Overexpression of the RasGEF Q ...

We demonstrate electro-optic ultrafast control of the optical quality factor of an on-chip silicon microcavity. The micrometer-sized cavity is formed by light confinement between two microring resonators acting as frequency selective mirrors. The ring resonators are integrated into p-i-n junctions enabling ultrafast injection and extraction of carriers. We show tuning of the cavity quality fact...

We show that by using a perturbed photonic Dirac-cone, one can realize ultra-narrow and finite Q-factor peak in the wavevector space, with both value width separately tunable. also discuss lower bound minimal viable given Q-value while maintaining sufficient Q differentiation among modes. The strong angular frequency Q-selection finds applications optical devices where angle- frequency-selectio...

Bound states in the continuum (BICs) have attracted a lot of interest field nanophotonics, and provide an important physical mechanism to realize high quality (Q) factor resonance. However, practice, manufacturing error will greatly affect Q factor. In this paper, we propose asymmetric metasurface supporting near merging BIC under normal incidence. Such can achieve higher (>107) than common ...

Let Fq be a finite field of odd order q. In this paper, the irreducible factorization of x2 pr − 1 over Fq is given in a very explicit form, where a, b, c are positive integers and p, r are odd prime divisors of q−1. It is shown that all the irreducible factors of x2 pr − 1 over Fq are either binomials or trinomials. In general, denote by vp(m) the degree of prime p in the standard decompositio...