Israel Ury

Direct amplitude modulation of short‐cavity GaAs lasers up to X‐band frequencies

Experimental and theoretical studies indicate that a high‐frequency laser with bandwidths up to X‐band frequencies (≳10 GHz) should be one having a short cavity with a window structure, and preferably operating at low temperatures. These designs would accomplish the task of shortening the photon lifetime, increasing the intrinsic optical gain, and increasing the internal photon density without inflicting mirror damage. A modulation bandwidth of >8 GHz has been achieved using a 120‐μm laser without any special window structure at room temperature.

A monolithic integration of GaAs/GaAlAs bipolar transistor and heterostructure laser

A GaAlAs double-heterostructure laser has been monolithically integrated with a heterojunction bipolar transistor on a GaAs substrate. Integration is achieved by means of a mutually compatible structure formed by Be ion implantation. Typical pulsed threshold currents for the laser are 60 mA, and the transistors have a typical common-emitter current gain of 900.

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.

Integration of an injection laser with a Gunn oscillator on a semi‐insulating GaAs substrate

The integration of an injection semiconductor laser with an active electronic device (Gunn oscillator) in a single epitaxial crystal device is demonstrated.

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.

11‐GHz direct modulation bandwidth GaAlAs window laser on semi‐insulating substrate operating at room temperature

We have demonstrated a direct modulation bandwidth of up to 11 GHz in a window GaAlAs buried heterostructure laser fabricated on a semi-insulating substrate, operating at room temperature.

Coherent coupling of diode lasers by phase conjugation

We report experimental demonstrations of the use of a photorefractive barium titanate ring passive phase conjugate mirror in the coherent coupling of two GaAlAs diode lasers. By cooling the crystal towards its tetragonal to orthorhombic phase transition, we were also able to achieve infrared photorefractive phase conjugation with gain.

Passive and active mode locking of a semiconductor laser without an external cavity

This letter describes the first attempt to passively and actively mode lock a discrete semiconductor laser, i.e., one not coupled to an external cavity. Beat notes of the longitudinal modes of a 1.97-mm-long GaAlAs laser have been observed at 17.7 GHz. The spectral width of the beat note was approximately 100 kHz. Stable passive mode locking has been observed under appropriate operating conditions. Active mode locking by an externally injected microwave signal was also achieved.

Monolithic optoelectronic integration of a GaAlAs laser, a field‐effect transistor, and a photodiode

A low threshold buried heterostructure laser, a metal-semiconductor field-effect transistor, and a p-i-n photodiode have been integrated on a semi-insulating GaAs substrate. The circuit was operated as a rudimentary optical repeater. The gain bandwidth product of the repeater was measured to be 178 MHz.

GaAs‐GaAlAs injection lasers on semi‐insulating substrates using laterally diffused junctions

Low‐threshold GaAs‐GaAlAs lasers operating in a stable single mode have been fabricated using laterally diffused junctions. The lasers are fabricated on semi‐insulating substrates and can be integrated with other components.