Spectral characteristics of long-wavelength two-segment multiquantum well distributed-feedback (DFB) lasers

1995 ◽  
Author(s):  
Guo P. Li ◽  
Toshi Makino
Keyword(s):  
Spectral Characteristics ◽  
Distributed Feedback ◽  
Long Wavelength ◽  
Multiquantum Well

1.5 μm compressive-strained multiquantum-well 20-wavelength distributed-feedback laser arrays

1992 ◽  
Vol 28 (9) ◽  
pp. 824 ◽  
Author(s):  
C.E. Zah ◽  
P.S.D. Lin ◽  
F. Favire ◽  
B. Pathak ◽  
R. Bhat ◽  
...  
Keyword(s):  
Distributed Feedback ◽  
Distributed Feedback Laser ◽  
Laser Arrays ◽  
Multiquantum Well

S cones: Evolution, retinal distribution, development, and spectral sensitivity

2013 ◽  
Vol 31 (2) ◽  
pp. 115-138 ◽  
Author(s):  
DAVID M. HUNT ◽  
LEO PEICHL
Keyword(s):  
Spectral Sensitivity ◽  
Spectral Characteristics ◽  
Primary Role ◽  
Long Wavelength ◽  
Representative Species ◽  
Cone Pathway ◽  
Cone Development ◽  
High Acuity ◽  
Retinal Distribution

AbstractS cones expressing the short wavelength-sensitive type 1 (SWS1) class of visual pigment generally form only a minority type of cone photoreceptor within the vertebrate duplex retina. Hence, their primary role is in color vision, not in high acuity vision. In mammals, S cones may be present as a constant fraction of the cones across the retina, may be restricted to certain regions of the retina or may form a gradient across the retina, and in some species, there is coexpression of SWS1 and the long wavelength-sensitive (LWS) class of pigment in many cones. During retinal development, SWS1 opsin expression generally precedes that of LWS opsin, and evidence from genetic studies indicates that the S cone pathway may be the default pathway for cone development. With the notable exception of the cartilaginous fishes, where S cones appear to be absent, they are present in representative species from all other vertebrate classes. S cone loss is not, however, uncommon; they are absent from most aquatic mammals and from some but not all nocturnal terrestrial species. The peak spectral sensitivity of S cones depends on the spectral characteristics of the pigment present. Evidence from the study of agnathans and teleost fishes indicates that the ancestral vertebrate SWS1 pigment was ultraviolet (UV) sensitive with a peak around 360 nm, but this has shifted into the violet region of the spectrum (>380 nm) on many separate occasions during vertebrate evolution. In all cases, the shift was generated by just one or a few replacements in tuning-relevant residues. Only in the avian lineage has tuning moved in the opposite direction, with the reinvention of UV-sensitive pigments.

Narrow-linewidth strained-layer 1.5 μm multiquantum well distributed feedback lasers

1991 ◽  
Vol 27 (8) ◽  
pp. 645
Author(s):  
S.J. Wang ◽  
Y. Twu ◽  
T. Tanbun-Ek ◽  
R.A. Logan ◽  
N.K. Dutta ◽  
...  
Keyword(s):  
Distributed Feedback ◽  
Distributed Feedback Lasers ◽  
Narrow Linewidth ◽  
Strained Layer ◽  
Multiquantum Well
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