The Group Refractive Index of Air

1968 ◽  
Vol 7 (7) ◽  
pp. 1408 ◽  
Author(s):  
L. E. Wood ◽  
M. C. Thompson
Keyword(s):  
Refractive Index ◽  
Group Refractive Index

Minimal group refractive index dispersion and gain evolution in ultra-broad-band quantum cascade lasers

2002 ◽  
Vol 14 (12) ◽  
pp. 1671-1673 ◽  
Author(s):  
C. Gmachl ◽  
A. Soibel ◽  
R. Colombelli ◽  
D.L. Sivco ◽  
F. Capasso ◽  
...  
Keyword(s):  
Refractive Index ◽  
Quantum Cascade Lasers ◽  
Broad Band ◽  
Refractive Index Dispersion ◽  
Minimal Group ◽  
Quantum Cascade ◽  
Group Refractive Index ◽  
Cascade Lasers

scholarly journals Group refractive index reconstruction with broadband interferometric confocal microscopy

2008 ◽  
Vol 25 (5) ◽  
pp. 1156 ◽  
Author(s):  
Daniel L. Marks ◽  
Simon C. Schlachter ◽  
Adam M. Zysk ◽  
Stephen A. Boppart
Keyword(s):  
Refractive Index ◽  
Confocal Microscopy ◽  
Group Refractive Index

REFRACTIVE INDEX OF He4: LIQUID

1958 ◽  
Vol 36 (7) ◽  
pp. 884-898 ◽  
Author(s):  
M. H. Edwards
Keyword(s):  
Refractive Index ◽  
Experimental Error ◽  
Saturated Vapor ◽  
Liquid Density ◽  
Phase Index ◽  
Vertical Tangent ◽  
Group Refractive Index ◽  
Relative Measurements ◽  
Λ Point

Changes in the phase refractive index n with temperature have been measured between 1.6 and 4.2° K at λ = 5462.27 Å, for liquid He4 at its saturated vapor pressure, using a metal optical cryostat and a Jamin interferometer. A novel adaptation of the Jamin interferometer has been made so that, in addition, an absolute determination of the group refractive index, nG, could be made using white light of "effective wavelength" 5595 ± 40 Å. When the dispersion correction is made, the phase index for the Hg green line at T55E = 3.700° K is n = 1.026124 ± 0.000035. The relative measurements have been adjusted to this value. The more than 200 experimental points show a random scatter of less than 5 × 10−6 in index. Using Kerr's density data the polarizability is thus (N0α) = (0.12454 ± 0.00021) cm3 mole−1 at λ = 5462.27 Å, for liquid He4 at 3.7 °K. Within experimental error (N0α) is found to be independent of temperature. Thus the refractive index data may be considered as a measurement of the liquid density and coefficient of expansion.The region near the λ-point is of special interest. The expansion coefficient determined from the refractive index, βn, may be represented within experimental error by 103βnI = +41.5 + 14.5 log|T−Tλ| for T > Tλ, from about 0.1° above Tλ to within 0.01° of Tλ; and by 103βnII = −1.5 + 14.5 log |T−Tλ| for T < Tλ, from about 0.1° below Tλ to within 0.002° of Tλ. This implies that the density–temperature curve has both a vertical tangent and a point of inflection at the λ-point; and that the maximum in density occurs about 0.001° above the λ-point.

In situ measurement of group refractive index using tandem low-coherence interferometer

2006 ◽  
Vol 266 (1) ◽  
pp. 214-217 ◽  
Author(s):  
H. Matsumoto ◽  
K. Sasaki ◽  
A. Hirai
Keyword(s):  
Refractive Index ◽  
In Situ Measurement ◽  
Low Coherence ◽  
Group Refractive Index

scholarly journals Group Refractive Index of Nanocrystalline Yttria-Stabilized Zirconia Transparent Cranial Implants

2021 ◽  
Vol 9 ◽  
Author(s):  
David L. Halaney ◽  
Nitesh Katta ◽  
Hamidreza Fallah ◽  
Guillermo Aguilar ◽  
Thomas E. Milner
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Spectral Range ◽  
Laser Speckle ◽  
Yttria Stabilized Zirconia ◽  
Optical Systems ◽  
Stabilized Zirconia ◽  
Swept Source ◽  
Group Refractive Index ◽  
Cranial Implants

Transparent “Window to the Brain” (WttB) cranial implants made from a biocompatible ceramic, nanocrystalline Yttria-Stabilized Zirconia (nc-YSZ), were recently reported. These reports demonstrated chronic brain imaging across the implants in mice using optical coherence tomography (OCT) and laser speckle imaging. However, optical properties of these transparent cranial implants are neither completely characterized nor completely understood. In this study, we measure optical properties of the implant using a swept source OCT system with a spectral range of 136 nm centered at 1,300 nm to characterize the group refractive index of the nc-YSZ window, over a narrow range of temperatures at which the implant may be used during imaging or therapy (20–43°C). Group refractive index was found to be 2.1–2.2 for OCT imaging over this temperature range. Chromatic dispersion for this spectral range was observed to vary over the sample, sometimes flipping signs between normal and anomalous dispersion. These properties of nc-YSZ should be considered when designing optical systems and procedures that propagate light through the window, and when interpreting OCT brain images acquired across the window.

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