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The vision of microchips that benefits from the high data rates of optical links has recently lead to novel concepts for the monolithic integration of active gain materials on silicon. In this letter, we use template-assisted selective epitaxy (TASE) for the monolithic integration of GaAs microsubstrates on silicon, which allows the subsequent integration of lattice-matched III–V laser cavities. We demonstrate the room-temperature operation of optically pumped microdisk-lasers with hexagonal top-facets and diameters as low as $1.2~\mu \text{m}$. The devices exhibit uniform emission spectra, low lasing thresholds of $P_{\mathrm{ th}}={13.6} \pm {0.7}$ pJ/pulse, and a high-temperature stability (${T}_{{0}} ={370}$ K). Scanning electron microscope and photoluminescence analysis of larger devices with a flat top-facet reveal a rotation of the crystal orientation and further reduce lasing thresholds. Our results show that the monolithic integration of III–V microsubstrates on silicon offers a versatile platform for on-chip light sources with excellent optical properties. [ABSTRACT FROM AUTHOR]

A GaAs/InGaAs microcylinder laser in diameter of $15~\mu $ m connected with a 2- $\mu $ m wide output waveguide is fabricated using standard photolithography and inductively coupled plasma etching technique. With the output waveguide, we realize the directional emission with the pulsed lasing operation wavelength of 1060 nm at room temperature. The maximum output power is $\sim 6~\mu $ W and the minimum threshold current is 2 mA, which is comparatively low compared with previous reported GaAs material microlasers. A single mode operation is achieved near threshold current at the wavelength of 1060 nm. Mode characteristics are calculated and analyzed by 2-D finite-difference time-domain simulation. The small volume, low threshold current, and low energy consumption make the GaAs/InGaAs microcylinder laser we presented a promising light source for optical interconnection on chip. [ABSTRACT FROM PUBLISHER]

The retro-reflector structure of semiconductor ring laser (RR-SRL) has been further miniaturized by redesigning its total-internal-reflection parabolic mirrors. The SRL device with new RR structures is fabricated successfully and identical output properties have been observed from the clockwise and the counterclockwise directions. The static stably switching and locking regions of both the main-mode and first sidemode have been measured, which are \sim5 and \sim6 GHz, respectively. The fast switching speed of \sim40 ps and error-free 10-Gb/s all-optical switching is achieved, which confirms the potential of these SRLs for high-speed all-optical digital applications. [ABSTRACT FROM PUBLISHER]

We developed a new method to fabricate a silica microsphere coated by a thin layer of Er : Yb-doped phosphate glass. The coated microsphere possessed high-Q whispering-gallery modes and formed single-mode and multimode microlasers in the both 1550- and 1040-nm bands. A low-loss fiber taper was used to not only launch the pump power around 980 nm into the microsphere, but also collect the resulting laser emissions. In our experiment, the threshold pump power as low as 30 muW of a single longitudinal mode was obtained. [ABSTRACT FROM PUBLISHER]

We describe a linear-geometry microcavity laser with microloops as end reflectors to achieve single-directional output. Finite-difference time-domain simulation is used to optimize the microloop mirror (MLM) performance and simulate the laser operation. We show that a single-directional microlaser with cavity length as small as 25 μm can be realized. A method to obtain higher output power from the microlaser with widened gain medium (WGM) is discussed. An initial fabrication of the MLM-WGM laser with transparent MLM formed by quantum-well intermixing is presented. A low-lasing threshold of ∼0.4 mA is achieved. [ABSTRACT FROM PUBLISHER]

We show for the first time that the longitudinal-mode discrimination in a birefringently filtered laser can be tuned through the variation of the waveplating action of the gain crystal. In this way, the laser can be optimized for either high intermodal discrimination or for frequency tuning with reduced output power rolloff. Up to 760 mW of single-frequency 1064-nm output is obtained from a compact diode-pumped source that can be frequency chirped over 6.5 GHz. [ABSTRACT FROM PUBLISHER]