The fabrication and optical properties of an erbium-doped gallium phosphide microdisk resonator pumped by a Ti-sapphire laser at 980 nm were investigated. Enhanced Er3+ intra-4f-shell photoluminescence was observed in the microdisk resonator compared to a thin film, and is attributed to a microcavity effect. At low pumping power intensity, the photoluminescence from erbium-doped gallium phosphide microdisks is an order of magnitude more intense than that from a thin film sample.

Summary form only given. We have discussed a novel microcavity structure, which is a combination of one-dimensional bandgap structure and photonic wire. We have successfully demonstrated the fabrication of the suspended photonic-wire microcavity, which is an important step towards the realization of microcavity lasers based a photonic-band-gap structure.

We describe a novel pulse-delayed scheme to realize degenerate optical parametric amplification in chi((3)) planar waveguides. The scheme utilizes two identical birefringent plates placed before and after a chi((3)) planar waveguide to implement a single-arm, pulse-multiplexed nonlinear Mach-Zehnder interferometer. Using this scheme, we demonstrate ultrafast degenerate optical parametric amplification in AlGaAs waveguides.

We report on the fabrication and characterization of broadband Bragg filters in microfabricated AlGaAs waveguides. Electron-beam lithography and chemically assisted ion-beam etching were used to fabricate first-order gratings with 250 nm period. Bragg filters with rejection bandwidth ∼15 nm and centered at ∼1.6 μm are demonstrated.

A strongly-guided one-dimensional (1-D) waveguide called a photonic wire has high spontaneous emission coupling efficiency, enabling one to realize low-threshold lasers. Combined with the use of 1-D photonic bandgap structures consisting of arrays of holes etched within the photonic wire, novel microcavity lasers can be realized, We report the nanofabrication of a photonic bandgap structure for 1.5 mu m wavelength along a InGaAsP photonic wire, and discuss numerical simulations for its electrodynamics.

We have obtained directional light output from a recently realized InGaAsP photonic-wire microcavity ring lasers. The output was achieved by fabricating a 0.45-/spl mu/m-wide U-shape waveguide next to a 10-/spl mu/m diameter microcavity ring laser. The laser has a threshold pump power of around 124 /spl mu/W when optically pumped at 514 nm. It is comparable to the former structure without output coupling. The output coupling efficiency can be controlled carefully by choosing the spacing between the laser cavity and the waveguide.

We report all-optical switching with low-peak power in a microfabricated AlGaAs waveguide operating at 1.6 mu m. We show that by using a 1-cm long microfabricated strongly-guided waveguide with 0.8 mu m by 0.9 mu m mode cross-sectional area, switching is achieved with an average power of 1.2 mW for 82-MHz mode-locked 430 fs pulses. The estimated peak pump power and pulse energy inside the microfabricated waveguide were similar to 30 W and similar to 14.6 pJ, respectively, which is 5-10 times lower than the values needed with conventional waveguides. In terms of a practicality index defined via switching power times waveguide length, this waveguide has around the best value.

We report experimental results from an erbium-doped gallium phosphide microdisk resonator pumped by a Ti-sapphire laser at 980 nm. Fabrication and characterization of the microdisk resonator are discussed. Enhanced Er+3 intra-4f-shell photoluminescence was observed in the microdisk resonator due to microcavity effect and compared to a thin film sample. At low pumping power intensity, the photoluminescence from erbium-doped gallium phosphide microdisks is an order stronger than that from a thin film sample.

We have achieved lasing in a strongly guided semiconductor waveguide with mode area as small as 0.02 mu m(2) (lambda = 1.4 mu m). The lasing action takes advantage of the large enhancement of stimulated emission in the waveguide and its suppression of unwanted dipole emission. We call the waveguide a photonic wire. The laser cavity is a high-Q microcavity ring resonator formed by the photonic wire and has a small cavity mode volume of 0.27 mu m(3). The lasing behaviors are consistent with theory. Laser outputs can be obtained via photon tunneling to adjacent waveguides. The laser realized will allow us to study spontaneous emission and lasing in nanofabricated waveguide structures.

Recently, Ho et. al. showed that a thin 2-dimensional dielectric waveguide with a large core and cladding refractive index difference can be used to modify the spontaneous emission of an active medium in the waveguide1. The modification of the spontaneous emission is a result of the change in photon density of states in the 2-D potential well for photons. We may call such a strongly guided dielectric waveguide a dielectric photonic well.

Microdisk lasers with three InGaAs/InAlGaAs quantum wells were demonstrated for the first time. The selective etching method used to fabricate the laser structure is discussed. Lasers 20 mu m in diameter lased with single mode at 1.5- mu m wavelength when optically pumped by a pulsed argon-ion laser at 80 K.<>

We report our experiment on the use of a double-disk structure to couple light output from a microdisk laser which allows us to maintain a high Q value of the microdisk resonator. The small photon leakage rate from the lower lasing disk to the top waveguiding disk can be carefully controlled by choosing the distance between the two disks. Various structures can be fabricated on the top disk to couple the light out. In this letter, a simple opening in the top disk is used for output coupling.

A simple approximation is developed for solving the “whispering gallery modes” of a microdisk laser structure using conformal transformation and the WKB approximation. Using this method the spontaneous emission coupling factor of microdisk lasers is estimated. The result predicts a β value of the order of 10-1.

The modification of the spontaneous emission from various dipoles in a cylindrical dielectric waveguide is studied as a function of the refractive index and the radius of the waveguide. It is found that the emission rates of the axial dipoles and the radial dipoles can be modified to enhance greatly the fraction of radial dipole emission that goes into the guided lasing modes. The total emission from the axial dipoles can be suppressed. This combination gives a high spontaneous-emission factor β for a microcavity ring laser. Other microlaser structures that have high β values are also discussed. We conclude that microlasers based on strongly guided single-mode dielectric waveguides are promising devices for achieving high β values and low lasing thresholds.

The performance of eight different BiCMOS logic configurations is discussed. The Z-type structure is found to be the most promising. The characteristics of Z-type inverters for Si MESFET and GaAlAs MODFET technologies are analyzed. The analysis shows that bipolar complementary structures, in general, can provide superior performance to other logic structures, and that BiCMES and BiCMOD structures can operate at higher speeds and lower power than BiCMOS