Noise-equivalent sensitivity of photoacoustics

Noise-equivalent sensitivity of photoacoustics.

The fundamental limitations of photoacoustic microscopy for detecting optically absorbing molecules are investigated both theoretically and experimentally. We experimentally demonstrate noise-equivalent detection sensitivities of 160,000 methylene blue molecules (270 zeptomol or 2.7×10-19  mol) and 86,000 oxygenated hemoglobin molecules (140 zeptomol) using narrowband continuous-wave photoacous...

An equivalent noise investigation of saccadic suppression.

Visual stimuli presented just before or during an eye movement are more difficult to detect than those same visual stimuli presented during fixation. This laboratory phenomenon--behavioral saccadic suppression--is thought to underlie the everyday experience of not perceiving the motion created by our own eye movements-saccadic omission. At the neural level, many cortical and subcortical areas r...

Noise and Equivalent Circuit of Double Injection

.Measurements o~ the high-frequ~ncy noi:e of a silicon double-injection diode result in (i'l)=a• 4kT ( 1/r) ~if With a= 1.04 and m agreement With the literature. A new interpretation demands Nyquist noise with a 121 in these devices at high frequencies. This is in accord with an equivalent circuit derived for the doubleinjection process. Speculations are made on the general validity of Nyquist ...

Noise sensitivity

Biomedical photoacoustics in China☆

During the last decade, along with its explosive growth globally, biomedical photoacoustics has become a rapidly growing research field in China as well. In particular, photoacoustic tomography (PAT), capable of imaging intact biological tissue in vivo at great depths, has generated intense interest among Chinese researchers. This review briefly summarizes the current status and recent progress...