We study, theoretically and experimentally, intensity noise induced by double Rayleigh scattering in long optical fibers. The results of the theoretical model are compared to experimental results performed with a high-coherence-length laser with a frequency noise spectrum that is dominated by 1/fν noise. Excellent quantitative agreement between theoretical and experimental RF spectra were obtai...

The amount of noise included in a hyperspectral image limits its application and has a negative impact on hyperspectral image classification, unmixing, target detection, and so on. In hyperspectral images, because the noise intensity in different bands is different, to better suppress the noise in the high-noise-intensity bands and preserve the detailed information in the low-noise-intensity ba...

We demonstrate narrow-linewidth-stimulated Brillouin lasers at 1064 nm from ultra-high-Q silica wedge disk resonators on silicon. Fundamental Schawlow-Townes frequency noise of the laser is on the order of 0.1 Hz2/Hz. The technical noise spectrum of the on-chip Brillouin laser is close to the thermodynamic noise limit of the resonator (thermorefractive noise) and is comparable to that of ultra-...

Background: In Neonatal intensive care units (NICU) different sound intensities and frequencies are produced from different sources, which may exert undesirable physiological effects on the infants. The aim of this study was to determine the noise level and its sources in the NICU and neonatal ward of Al-Zahra Hospital of Rasht, Iran. Methods: In this descriptive cross-sectional study, the inte...

The short-term sensitivity of a several-kilometers long fiber-optic gyroscope (FOG) is limited mainly by thermal phase noise (TPN) and relative intensity (RIN). Increasing the modulation frequency decreases TPN but not RIN since it behaves as white noise. Here, we propose experimentally demonstrate that angular random walk (ARW) can be effectively decreased suppressing at its third-order harmon...

background: in neonatal intensive care units (nicu) different sound intensities and frequencies are produced from different sources, which may exert undesirable physiological effects on the infants. the aim of this study was to determine the noise level and its sources in the nicu and neonatal ward of al-zahra hospital of rasht, iran. methods: in this descriptive cross-sectional study, the inte...

PURPOSE The Lombard effect describes the tendency for speakers to increase pitch, intensity, and duration in the presence of noise. It is unclear whether these modifications are uniformly applied across all words within an utterance or whether information-bearing content words are further enhanced compared with function words. In the present study, the authors investigated the influence of ling...

A circadian oscillator driven by external noise and internal noise has been studied by use of the chemical Langevin equation method. When the system is near a Hopf bifurcation and driven by internal noise only, it is found that the coherence resonance phenomenon can be induced by the internal noise. When the system is simultaneously driven by internal and external noise, it is found that extern...