Refractive index step and optical confinement in Ga0.86In0.14As0.13Sb0.87/Ga0.73Al0.87As0.02Sb0.98 double heterostructure lasers emitting at 2.2 μm

1993 ◽  
Vol 29 (14) ◽  
pp. 1240 ◽  
Author(s):  
M.S.S. Loural ◽  
M.S.S. Loural ◽  
M.B.Z. Morosini ◽  
J.L. Herrer-Pérez ◽  
A.A.G. von Zuben ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Confinement ◽  
Double Heterostructure

NUMERICAL SIMULATION OF OPTICAL CONFINEMENT IN ZnO BASED HETEROSTRUCTURES AT 375-NANOMETER WAVELENGTH

2008 ◽  
Vol 22 (12) ◽  
pp. 1985-1995 ◽  
Author(s):  
M. P. BHOLE ◽  
E. P. SAMUEL ◽  
D. S. PATIL
Keyword(s):  
Numerical Simulation ◽  
Layer Thickness ◽  
Mole Fraction ◽  
Active Layer ◽  
Active Layer Thickness ◽  
Optical Confinement ◽  
Double Heterostructure ◽  
Active Layers ◽  
Junction Plane ◽  
Different Thickness

Numerical simulation of optical confinement in simple double heterostructure of ZnO / Mg x Zn 1-x O and hybrid double heterostructure of Al x Ga 1-x N/ZnO have been carried out at 375 nanometer wavelength using MATLAB. Field distribution along the junction plane has been studied as a function of mole fractions of Mg and Al for different thickness of active layers. The spread of field has been estimated as a function of mole fractions and articulated as Full Width at Half Maximum (FWHM). It was found to be decreasing nonlinearly with increase of Mg mole fraction in simple heterostructure and increasing in a nonlinear manner with increase of Al mole fraction in hybrid heterostructure. FWHM deduced from our analysis was 0.265 micron for 9% and 0.16 micron for 30% Mg mole fraction. For hybrid heterostructure, FWHM values estimated were 0.13 micron and 0.1475 micron for corresponding Al mole fraction values of 9% and 30%, respectively. The narrower confinement of field intensity around the center of the active layer for the higher values of Mg mole fraction has been attributed to an increase of refractive index step between active and barrier layers. The confinement factor as a function of mole fractions and active layer thickness has been explored, and it was found to be increasing with active layer thickness. Our analysis explores the optical confinement of mode 0 in simple and hybrid heterostructures of ZnO .

TEM characterization of proton-exchanged LiNbO3 optical waveguides

1986 ◽  
Vol 44 ◽  
pp. 480-481
Author(s):  
W. E. Lee
Keyword(s):  
Refractive Index ◽  
Benzoic Acid ◽  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Index Of Refraction ◽  
Optical Measurements ◽  
Lithium Ions ◽  
Wide Channel ◽  
Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

Light microscopy of ceramics

1993 ◽  
Vol 51 ◽  
pp. 908-909
Author(s):  
Walter C. McCrone
Keyword(s):  
Refractive Index ◽  
Light Microscopy ◽  
Light Microscope ◽  
Polarized Light ◽  
Refractive Indices ◽  
Complete Coverage ◽  
The Subject ◽  
Lower Refractive Index

An excellent chapter on this subject by V.D. Fréchette appeared in a book edited by L.L. Hench and R.W. Gould in 1971 (1). That chapter with the references cited there provides a very complete coverage of the subject. I will add a more complete coverage of an important polarized light microscope (PLM) technique developed more recently (2). Dispersion staining is based on refractive index and its variation with wavelength (dispersion of index). A particle of, say almandite, a garnet, has refractive indices of nF = 1.789 nm, nD = 1.780 nm and nC = 1.775 nm. A Cargille refractive index liquid having nD = 1.780 nm will have nF = 1.810 and nC = 1.768 nm. Almandite grains will disappear in that liquid when observed with a beam of 589 nm light (D-line), but it will have a lower refractive index than that liquid with 486 nm light (F-line), and a higher index than that liquid with 656 nm light (C-line).

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