ABSTRACT
We report the optical characterization of an InP structure constituted by waveguides coupled to microcavity disk resonators. The lateral waveguide confinement is obtained by deep reactive ion etching through the guiding layer. We demonstrate the possibility of tuning optically the resonance wavelength into the illuminating disk resonator. We obtained a blueshift of 3 nm by laser irradiation at 980 nm corresponding to a photoinduced change in the effective refractive index of 6 x 10(-3). The InP structure behaves as a tunable optical demultiplexer.
ABSTRACT
From a comparison with the spectrum of NiF, a low-lying (2)Sigma(+) state is expected to lie in the first 2000 cm(-1) above the ground X(2)Pi(3/2) state of NiCl. The identification of this (2)Sigma(+) (v = 0) state (at 1768 cm(-1)) has been carried out through the analysis of two electronic transitions (2)Pi(3/2)-(2)Sigma(+) (22 720 cm(-1)) and (2)Pi(1/2)-(2)Sigma(+) (23 210 cm(-1)) recorded by high-resolution Fourier transform spectroscopy. Dispersed fluorescence spectroscopy allowed these transitions to be located on an absolute energy-level diagram that includes the previously studied electronic states. Copyright 2000 Academic Press.
ABSTRACT
The A'(1)Pi-X(1)Sigma(+) near-infrared system of CaO was observed for the first time at high resolution using a Fourier transform spectrometer. The A'(1)Pi-X(1)Sigma(+) chemiluminescence was excited in a Ca + N(2)O flame produced in a Broida-type oven. More than 3000 rotational lines, classified into 19 bands involving the A'(1)Pi 0 /= 2) levels with the nearby b(3)Sigma(+) (v-2) levels has been detected. An extended set of A'(1)Pi (v = 0-3) data has been obtained which is suitable for use in a future multistate deperturbation analysis of the a(3)Pi approximately A'(1)Pi approximately b(3)Sigma(+) approximately A(1)Sigma(+) complex of excited states. The new near-infrared spectra of the A'(1)Pi-X(1)Sigma(+) transition of CaO also permits the first direct high-resolution linkage between the orange and green systems and the near-infrared bands. Copyright 2000 Academic Press.
ABSTRACT
The A(1)Sigma(+)-X(1)Sigma(+) chemiluminescence spectrum of SrO was observed using a Fourier transform spectrometer. SrO was produced in a Broida-type oven from the Sr + N(2)O reaction. A total of 75 bands from (88)SrO, (87)SrO, and (86)SrO were measured in the range of 7600-13 600 cm(-1) at a resolution of 0.04 cm(-1). The vibrational levels of the ground state were observed up to v" = 12 and over 10 000 rovibrational lines with J as high as 153 were analyzed at a precision of about 0.005 cm(-1). Significantly improved spectral constants for the ground state were obtained by representing the perturbed excited state by term values and by adding the known microwave data and infrared data to our fit. Strong perturbations were observed in the upper A state. The vibrational levels of the A(1)Sigma(+) state were measured up to v' = 8 and some new perturbations are reported. Copyright 2000 Academic Press.
ABSTRACT
The A(2)Pi(r)-X(2)Sigma(+) emission spectrum of the magnesium monobromide radical, MgBr, has been recorded with a Fourier transform spectrometer modified to record double-sided interferograms. The emission spectra of the Deltav = -2, -1, 0, +1 bands were generated in a microwave discharge of a mixture of argon and vaporized MgBr(2). The Deltav = 0 and -1 bands were rotationally resolved, but the F(2) spin component (A(2)Pi(3/2)) in the (1, 1), (1, 2) and vibrational bands with v' > 1 were missing in our spectra because of a strong predissociation in the A state. The molecular constants in both electronic states were determined for the two bromine isotopomers. The r(0) bond length in the A state is about 2.327 Å, which is about 0.02 Å shorter than in the ground state. Franck-Condon factors were calculated from the Rydberg-Klein-Rees potentials, and they reproduce the observed relative intensities of the bandheads. An upper limit for the dissociation energy (D(0)(0)) was obtained as 26 268.4 cm(-1), based on the absence of the energy level with v = 1, A(2)Pi(3/2), J = 1.5 in our spectrum. Copyright 2000 Academic Press.
ABSTRACT
The molecular ion TiF+ has been observed for the first time using high-resolution spectroscopy. The ions were produced in the positive column of an AC glow discharge with a gas mixture of He/TiF4. A single-mode cw dye laser along with the velocity modulation detection technique was used to record an absorption spectrum in the spectral region 16 800-18 600 cm-1. The observed system was assigned to the 0-0 and 1-1 bands of the [17.6]3Delta-X3Phi transition of TiF+. The rotational analysis of the main subbands has been performed up to J values equal to 77 and 56 for the 0-0 and 1-1 bands, respectively. Despite a careful search, no intercombination band was observed. A set of effective molecular parameters has been determined, characterizing the v = 0, 1 levels of the [17.6]3Delta and X3Phi states. The spin-orbit constants Ae and the vibrational constants omegae, omegaexe have been estimated for both electronic states, as well as their equilibrium distances Re (1.7509 and 1.7800) Å for the [17.6]3Delta and X3Phi states, respectively). Copyright 1998 Academic Press.
