High-contrast level-crossing resonances in a small cesium vapor cell for applications in atomic magnetometry

AbstractWe recorded visual evoked potentials in response to square-wave contrast-reversal checkerboards undergoing a transition in the mean contrast level. Checkerboards were modulated at 4.22 Hz (8.45-Hz reversal rate). After each set of 16 cycles of reversals, stimulus contrast abruptly switched between a “high” contrast level (0.06 to 1.0) to a “low” contrast level (0.03 to 0.5). Higher contrasts attenuated responses to lower contrasts by up to a factor of 2 during the period immediately following the contrast change. Contrast-response functions derived from the initial second following a conditioning contrast shifted by a factor of 2–4 along the contrast axis. For low-contrast stimuli, response phase was an advancing function of the contrast level in the immediately preceding second. For high-contrast stimuli, response phase was independent of the prior contrast history. Steady stimulation for periods as long as 1 min produced only minor effects on response amplitude, and no detectable effects on response phase. These observations delineate the dynamics of a contrast gain control in human vision.

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Investigation of pernicious oscillation inside a LD-pumped cesium vapor cell

Journal of the Optical Society of America B ◽

10.1364/josab.35.002970 ◽

2018 ◽

Vol 35 (12) ◽

pp. 2970 ◽

Cited By ~ 1

Author(s):

Shunyan Wang ◽

Xiaoxu Liu ◽

Qiang Yu ◽

Guofei An ◽

He Cai ◽

...

Keyword(s):

Cesium Vapor ◽

Vapor Cell

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Femtotesla atomic magnetometry in a microfabricated vapor cell

Optics Express ◽

10.1364/oe.18.027167 ◽

2010 ◽

Vol 18 (26) ◽

pp. 27167 ◽

Cited By ~ 71

Author(s):

W. Clark Griffith ◽

Svenja Knappe ◽

John Kitching

Keyword(s):

Vapor Cell ◽

Atomic Magnetometry

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Bloch's Law for Contrast Increment Detection: The Effects of Pedestal Contrast and Light Level

Perception ◽

10.1068/v96l0606 ◽

1996 ◽

Vol 25 (1_suppl) ◽

pp. 149-149

Author(s):

R J Snowden

Keyword(s):

Visual System ◽

Temporal Summation ◽

Light Level ◽

High Light ◽

High Contrast ◽

Contrast Level ◽

Low Light ◽

Low Contrast ◽

Temporal Characteristics ◽

Test Grating

The duration over which contrast detection improves (Bloch's regime) decreases with increasing light level and is often thought to reflect the temporal characteristics of the visual system. There is also some evidence to suggest that the temporal characteristics of the visual system might also change with increasing contrast level (M A Georgeson, 1987 Vision Research27 765 – 780). Here we compare temporal summation for stimuli presented on a blank field or on a high contrast background. On each trial a test grating was presented for X ms with the use of a spatial-alternate forced-choice procedure. The test grating (2 cycles deg−1) was presented superimposed on a similar pedestal grating which was also present for 500 ms prior to and after the test grating. Pedestal contrasts of 0% and 32% were tested at mean luminance levels of 150 cd m−2 and 1.5 cd m−2. The results show that both increasing light level and increasing contrast level resulted in smaller temporal summation times. In the current conditions both these effects approximately halve the summation time such that for a stimulus of low light level and of low pedestal contrast the summation time was ∼60 ms; low light, high contrast ∼30 ms; high light, low contrast ∼30 ms; and high light, high contrast ∼15 ms. The results imply that the temporal response of the visual system quickens with increasing contrast.

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