Using the couple mode theory, the reflection spectrum, the peak reflectivity and the reflection bandwidth of several typical fiber grating filters have been theoretically analyzed and numerically simulated.
A new fast photoelectric recognition method of object colour isdiscribed, which is to determine object colour by use of the photovoltage ratio between two special colour light in transmission or reflection spectrum.
In this paper, the reflection coefficient of middle 1/R cantor potential barrier are calculated by the method of interference matrix. The results obtained show that there is self similarity in reflection spectrum. This property will be applied in other fields.
Using K-K relation, the data of reflection spectra of heavily-doped N-GaAs and N-InP are processed in the range of 50～2750cm~(-1) with 170SX model FT-IR instrument. The frequency of plasma ω_p, the damping coefficient γ, the free carrier concentration n, the mobility μ and the resistivity ρ are obtained.
The numerical fitting of the far-IR reflection spectra(70～360cm~(-1)) of the polycrystalline YBa_2Cu_3O_(7-δ) is given, using the Drude and its modified models. The curves of plasma frequency vs temperature and the gap frequency vs temperature are obtained, respectively. The drastic change in the strength of the 150cm~(-1) phonon at low tempcrature is found.
Five characteristic reflection peaks and three inversion structures have been observed in the far-infrared (40～360cm~(-1)) reflection spectra common to all these materials. In the mid-infrared region, there is another characteristic reflection peak of 580cm~(-1). In the absorption spectra two peaks have been found at 580～590 and 615～627cm~(-1).
The transmission and reflection spectra at wavelength between 0. 2 and 6. 0 μm, and photoluminescence spectra of Cd2SnO4 films deposited by RF reactive sputtering from a Cd-Sn alloy target have been measured. The optical properties of Cd2SnO4 films are analyzed and calculated theoretically in detail.
The transmission and reflectance spectrum of the sample showed a clear transmission valley/reflectance peak at 534 nm, indicating that the PC had a large photonic band gap in the range of visible wavelength.
The variation of reflectance spectrum induced by injection carrier in GaAlAs film is studied experimentally. The variation curves of reflectance spectrum after the carrier With the different concentration in GaAlAs film are given . This paper also gives the relation curve between the reflectance spectrum change and injection carrier concentration.
Based on the coupled mode theory,the chirped Moire grating formed by tow linear chirped fiber gratings was analyzed in detail via the matrix approach. A deeper insight into the relationship among its reflectance spectrum,time delay and the grating parameters,such as the length of the chirped Moire grating,the chirp parameter and the peak refractive index modulation,was obtained.
Results indicate that the reflectance spectrum shifts much due to the variation of periodic thickness. We also conclude that decreasing the thickness of thin-film layers with high refractive index can decrease the loss of DBR and increase its reflectivity. Moreover,changing contrarily the thickness of top and bottom DBR can increase the side-mode suppression ratio (SMSR) of vertical-cavity surface-emitting lasers(VCSEL).
Interband absorption and features in the reflection spectrum due to interband transitions have been calculated for an arbitrary ratio between the radiative and "phonon" lifetime of a combined polaron have been investigated.
Reflection spectrum of a cholesteric liquid crystal with structural defects
New qualitative features appear in the reflection spectrum of a cholesteric with two defects as the distance between them varies.
Method of the ratio of envelopes of the reflection spectrum for measuring optical constants and thickness of thin films
A spectrophotometric method is proposed that uses the ratio of envelopes of minima and maxima of the interference reflection spectrum for measuring optical constants of a film on a substrate.