Monolithic integration of an injection laser and a metal semiconductor field effect transistor

A new laser structure, the "T-laser", has been monolithically integrated with a MESFET on a semi-insulating GaAs substrate. Integration is achieved by means of a compatible structure in which the optically active layer of the laser also serves as the electrically active layer of the MESFET. Direct modulation of the laser by means of the transistor is demonstrated

Q-switched ruby laser alloying of Ohmic contacts on gallium arsenide epilayers

Ohmic contacts of AuGe have been produced on GaAs epilayers by laser alloying. The contacts possess morphological and electrical properties which are superior to those formed by conventional alloying

Be-implanted (GaAl)As stripe geometry lasers

GaAl)As double-heterostructure stripe geometry lasers have been fabricated using Be ion implantation. Pulsed threshold currents as low as 21 mA have been found. The light-vs-current characteristics were kink-free up to 10 mW output power and the measured differential quantum efficiency was 45%

Phase-locking characteristics of coupled ridge-waveguide InP/InGaAsP diode lasers

The phase-locking characteristics of two coupled, ridge waveguide InP/InGaAsP diode lasers emitting at 1.2 µm were investigated experimentally. The phase locking of the lasers was verified by the observation of phase-locked modes (supermodes) in the spectrally resolved near fields and distinct diffraction patterns in the far field. By independent control of the laser currents it was possible to vary continuously the mutual phase shift between the two phase-locked lasers and thus steer the far-field diffraction lobes. In addition, the separate current control could be utilized to obtain single longitudinal mode oscillation of the phase-locked lasers. Variation in one of the laser currents resulted then in tuning of the wavelength of this single mode over a range of 90 Å

Phased arrays of buried-ridge InP/InGaAsP diode lasers

Phase-locked arrays of buried-ridge InP/InGaAsP lasers, emitting at 1.3 µm, were grown by liquid phase epitaxy. The arrays consist of index-guided, buried-ridge lasers which are coupled via their evanescent optical fields. This index-guided structure makes it possible to avoid the occurrence of lower gain in the interchannel regions. As a result, the buried-ridge arrays oscillate mainly in the fundamental supermode, which yields single lobed, narrow far-field patterns. Single lobed beams less than 4° in width were obtained from buried-ridge InP/InGaAsP phased arrays up to more than twice the threshold current

Cd diffused mesa-substrate buried heterostructure InGaAsP/InP laser

A new type of buried heterostructure InGaAsP/InP lasers grown by a single-step liquid phase epitaxy on Cd diffused mesa substrate is described. These lasers exhibit excellent current and optical confinement. Threshold currents as low as 15 mA are achieved for a laser with a 2-µm-wide active region

A monolithically integrated optical repeater

A monolithically integrated optical repeater has been fabricated on a single-crystal semi-insulating GaAs substrate. The repeater consists of an optical detector, an electronic amplifier, and a double heterostructure crowding effect laser. The repeater makes use of three metal semiconductor field effect transistors, one of which is used as the optical detector. With light from an external GaAlAs laser incident on the detector, an overall optical power gain of 10 dB from both laser facets was obtained

InGaAsP p-i-n photodiodes for optical communication at the 1.3-µm wavelength

The preparation and properties of Cd-diffused p-n homojunction InGaAsP photodiodes designed specifically for operation at the 1.3-µm wavelength are described. At a reverse bias of 10 V, the dark current of these diodes was as low as 15 pA. The peak responsivity at 1.3-µm wavelength was 0.7 A/W. An impulse response (full width at half maximum) of 60 ps and a 3-dB bandwidth of 5.5 GHz were achieved.