COMPARISON BETWEEN THE INFLUENCES OF LAYER THICKNESSES AND ALAS MOLE FRACTION-X ON VERTICAL-CAVITY SURFACE-EMITTING LASERS

Based on the n(x, lambda), the calculation of the reflection spectrum for vertical cavity surface emitting lasers shows that the deviation of the central wavelength caused by the change of layer thickness is much more than that caused by the change of AlAs mole fractions. Therefore the control of the MBE growth rate is very important.

THE DEPENDENCE OF THE INVERSION LAYER THICKNESS ON THE FILM THICKNESS IN THIN-FILM SOI STRUCTURES

The dependence of the inversion-layer thickness on the film thickness in thin-film SOI structure is analyzed theoretically by using computer simulation. A new concept and parameter, the critical thickness of thin film all-bulk inversion, is introduced for the design of thin-film MOS/SOI devices. It is necessary to select the film thickness T(s1) close to the all-bulk strong inversion critical thickness in order to get high-speed and high-power operation of ultra-thin film MOS/SOI devices.

Interfacial behaviour of quantum well electrode/electrolyte: effect of redox species on EER spectra of a single quantum well GaAs vertical bar AlxGa1-xAs electrode

The EER spectra of a single quantum well GaAs\AlxGa1-xAs electrode were studied as a function of applied reverse bias in ferrocene, p-methyl nitrobenzene and hydroquinone+benzoquinone non-aqueous solutions. EER spectra were compared for different redox species and showed that a pronounced quantum-confined Stark effect and a Franz-Keldysh oscillation for a single quantum well electrode were obtained in the p-methyl-nitrobenzene- and hydroquinone+benzoquinone-containing solutions. A surface interaction of the single quantum well electrode with ferrocene led to fewer changes in the electric field of the space charge layer for reverse bias; this was suggested to explain the weak quantum-confined Stark effect and Franz-Keldysh oscillation effect observed for the single quantum well electrode in the ferrocene-containing solution. (C) 1997 Elsevier Science S.A.

Far-field and beam characteristics of vertical-cavity surface-emitting lasers

We have determined the far-field patterns and beam parameters of vertical-cavity surface-emitting lasers (VCSELs) with different structures. The results show that the window diameter and the active-layer aperture of VCSELs strongly influence laser far-field distributions and beam characteristics; for VCSELs with small window omega=5 mu m, only one dominant lobe has been observed in the far-field profiles, even though injected current was increased up to 2 Ith; and the smaller the ratio of the window diameter to the active-layer aperture, the larger is the far-field divergence. The laser structure dependence of the K factor has also been studied. (C) 1996 American Institute of Physics.

EFFECTIVE CAVITY LENGTH IN VERTICAL-CAVITY SURFACE-EMITTING LASER

Effective cavity length method is introduced to vertical cavity surface emitting laser for characterizing some properties, including reflectivity FWHM, mode wavelength and threshold gain. Some experiment results are demonstrated, showing the agreement of theoretical analysis with experiment.

PULSED ELECTRICAL OPERATION OF 1.5-MU-M VERTICAL-CAVITY SURFACE-EMITTING LASERS

Vertical cavity surface emitting lasers operating in the 1.3- and 1.5-mu m wavelength ranges are highly attractive for telecommunications applications. However, they are far less well-developed than devices operating at shorter wavelengths. Pulsed electrically-injected lasing at 1.5 mu m, at temperatures up to 240 K, is demonstrated in a vertical-cavity surface-emitting laser with one epitaxial and one dielectric reflector. This is an encouraging result in the development of practical sources for optical fiber communications systems.

Effect of Mesa Size on Thermal Characteristics of Vertical-cavity Surface-emitting Lasers

The effect of mesa size on the thermal characteristics of etched mesa vertical-cavity surfaceemitting lasers(VCSELs) is studied. The numerical results show that the mesa size of the top mirror strongly influences the temperature distribution inside the etched mesa VCSEL. Under a certain driving voltage, with decreasing mesa size, the location of the maximal temperature moves towards the p-contact metal, the temperature in the core region of the active layer rises greatly, and the thermal characteristics of the etched mesa VCSELs will deteriorate.

Array for 980nm Vertical Cavity Surface Emitting Diodes and Detectors

Both the vertical cavity surface emitting diodes and detectors are fabricated by using the epitaxial wafer with resonant cavity structure. Their characteristics are analyzed. The light emitters have high spectral purity of 4.8nm and high electroluminescence intensity of 0.7mW while injection current is 50mA. A 1*16 array of surface emitting light device is tested on line by probes and then used for module. The light detectors have wavelength selectivity and space selectivity. The required difference in input mirror reflectivity between emitters and detectors can easily be achieved though varying the numbers of top DBR period by etching.