Refractive index and absorption measurement in a thin layer by two reflection measurements

Abstract

The analysis of two reflection spectra measuring the reflected power without and with reflection at the backside of a very thick substrate, as described in a previous paper [1], is used for implanted LiNbO3 samples. In the first case the profile of refractive index in the implanted layer can be evaluated for extra‐ordinary and ordinary light polarization. The measurement with reflections from the backside of the sample gives information about the amount and dispersion of absorption in the implanted layer. The decrease of this absorption by a thermal annealing at TA = 670 K is also clearly seen by the analysis.

Diffusion and recrystallization processes during annealing of N+- and P+-implanted LiNbO3

“…Similar results were found for P+-implanted layers, e.g. the same maximum values of the refractive index changes were attained [2]. An optical anisotropy was kept in the layers, also when implanted a t TI = 80 K with a high ion dose (Dp+ = 2 x 1OI6 em-").…”

Optical reflection and transmission through a flat system with a thick fluctuating layer

“…Because in most of the cases all reflection coefficients are of the same order of magnitude the independent measurement of Rf, and ( R f b ) ) allows the indirect determination of Tf,. I n a following paper [5] this will be demonstrated in the case of implanted LiNbO, samples, where a measurement of the absorption in the implanted layer is done by reflection measurements only. The higher-order Fourier components M , are proportional to Mo except the term AB*/CD* in the case of the reflection coefficient.…”

“…The determination of the transmission through a thin layer can be done by a second reflection measurement. The application of this proposal will be demonstrated in a subsequent paper [5] for the case of an implanted LiNbO, sample.…”

MBE growth and characterization of Hg based compounds and heterostructures

“…surface demonstrates that these long ridges also consist of terraces whose height difference is one monolayer and average width is approximately 180 A [22]. 14 , . , .n 2 That this is the case here, is demonstrated in Fig.…”

“…The absorption If the HgTe layer is less than 6 nm thick then the coefficient, aL, was determined by fitting the experimenheterostructure is a normal semiconductor, however, if tal transmission spectra to a theoretical description of the thickness is greater than 6 nm then the band structure the multi-layer system using standard matrix procedures is inverted, i.e. the F 6 and F 8 bands exchange places [14]. and the energy gap is negative.…”