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As a result, the SNR (Signal-to-noise ratio) for a fixed number of detected photons can be higher than that from a PMT. Conversely, the stochastic gain of a PMT typically requires more detected photons to obtain the same SNR. Mass production of silicon electronics by multiple vendors allows SiPMs to be made very cheaply relative to vacuum tubes.
The most important refinement is a definition of the camera signal nonlinearity better adapted to cameras with a higher dynamic range. The only two other major additions are: a) the total SNR curve which includes the spatial nonuniformities, and b) diagrams of horizontal and vertical profiles for a meaningful and well-arranged characterization ...
Photons seem well-suited to be elements of an extremely fast quantum computer, and the quantum entanglement of photons is a focus of research. Nonlinear optical processes are another active research area, with topics such as two-photon absorption , self-phase modulation , modulational instability and optical parametric oscillators .
A Feynman diagram (box diagram) for photon–photon scattering: one photon scatters from the transient vacuum charge fluctuations of the other. Two-photon physics, also called gamma–gamma physics, is a branch of particle physics that describes the interactions between two photons.
PPF values all photons from 400 to 700 nm equally, while YPF weights photons in the range from 360 to 760 nm based on a plant's photosynthetic response. [8] PAR as described with PPF does not distinguish between different wavelengths between 400 and 700 nm, and assumes that wavelengths outside this range have zero photosynthetic action.
Each dynode is held at a more positive potential, by ≈100 Volts, than the preceding one. A primary electron leaves the photocathode with the energy of the incoming photon, or about 3 eV for "blue" photons, minus the work function of the photocathode. A small group of primary electrons is created by the arrival of a group of initial photons.
Photons are massless particles of definite energy, definite momentum, and definite spin. To explain the photoelectric effect , Albert Einstein assumed heuristically in 1905 that an electromagnetic field consists of particles of energy of amount hν , where h is the Planck constant and ν is the wave frequency .
Due to the limited full-well capacity of conventional image pixel, the pixel will saturate when the light intensity is too strong. This is the reason that the dynamic range of the pixel is low. For the oversampled binary image sensor, the dynamic range is not defined for a single pixel, but a group of pixels, which makes the dynamic range high. [2]