Charge sensitive infrared phototransistors (CSIP) are well known for their capability for response spectrum tuning and single photon detection. In this paper, we established a physical model for a charge sensitive infrared phototransistor operating at 45μm wavelength using the Crosslight Apsys software. Several key physical mechanisms involved such as inter-subband optical transition and resona...

According to opponent-colors theory, a reddish surround induces greenness in a central test field. Color-appearance measurements verify this with a long-wavelength reddish surround (660 nm) but not with a short-wavelength reddish surround (440 nm). Surprisingly, a short-wavelength reddish surround shifts the appearance of a test toward redness. Four possible explanations are: (1) stray light fr...

Long-wavelength luminescent probes and sensors become increasingly popular. They offer the advantage of lower levels of autofluorescence in most biological probes. Due to high penetration depth and low scattering of red and NIR light such probes potentially enable in vivo measurements in tissues and some of them have already reached a high level of reliability required for such applications. Th...

An electroretinographic response of the human short wavelength (S) cone system can be distinguished from that of the longer wavelength (L or M) cone system by using ganzfeld short-wavelength stimulation at relatively high levels of retinal adaptation. The S cone response has both an a- and b-wave component in its ERG, both of which are slower than those of the L or M cone response at the same l...

Physiological studies of color have uncovered many puzzles. Here are four puzzles. First, neurons in the lateral geniculate nucleus (LGN; Fig. 1) are strongly color opponent, but the opponency does not correspond to Hering's fundamental opponent-color pairs (red–green, blue–yellow) (Webster et al., 2000); moreover, the color-tuning of the population of LGN cells is not balanced across color spa...

Long-wavelength sensitive (L) cone dark adaptation curves were measured with a 10-msec, 20' v.a., 650 nm test flash and a moderate intensity adapting field. When the 650 nm and 500 nm fields were equated for the L cones, the dark adaptation curve fell faster for the 500 nm field than for the 650 nm field. Over the range of adapting lights used, no adjustment of the intensities of the two fields...